Modern Pathology

Comment on HPV-independent, p53-wild-type vulvar intraepithelial neoplasia: a review of nomenclature and the journey to characterize acanthotic precursor lesions of the vulva. Parra-Herran C. et al Mod Pathol 2022 Apr 18 doi: 10.1038/s41379-022-01079-7

Massively parallel sequencing analysis of 68 gastric-type cervical adenocarcinomas reveals mutations in cell cycle-related genes and potentially targetable mutations

Gastric-type cervical adenocarcinoma (GCA) is an aggressive type of endocervical adenocarcinoma characterized by mucinous morphology, gastric-type mucin, lack of association with human papillomavirus (HPV) and resistance to chemo/radiotherapy. We characterized the landscape of genetic alterations in a large cohort of GCAs, and compared it with that of usual-type HPV-associated endocervical adenocarcinomas (UEAs), pancreatic adenocarcinomas (PAs) and intestinal-type gastric adenocarcinomas (IGAs). GCAs (n = 68) were subjected to massively parallel sequencing targeting 410-468 cancer-related genes. Somatic mutations and copy number alterations (CNAs) were determined using validated bioinformatics methods. Mutational data for UEAs (n = 21), PAs (n = 178), and IGAs (n = 148) from The Cancer Genome Atlas (TCGA) were obtained from cBioPortal. GCAs most frequently harbored somatic mutations in TP53 (41%), CDKN2A (18%), KRAS (18%), and STK11 (10%). Potentially targetable mutations were identified in ERBB3 (10%), ERBB2 (8%), and BRAF (4%). GCAs displayed low levels of CNAs with no recurrent amplifications or homozygous deletions. In contrast to UEAs, GCAs harbored more frequent mutations affecting cell cycle-related genes including TP53 (41% vs 5%, p < 0.01) and CDKN2A (18% vs 0%, p = 0.01), and fewer PIK3CA mutations (7% vs 33%, p = 0.01). TP53 mutations were less prevalent in GCAs compared to PAs (41% vs 56%, p < 0.05) and IGAs (41% vs 57%, p < 0.05). GCAs showed a higher frequency of STK11 mutations than PAs (10% vs 2%, p < 0.05) and IGAs (10% vs 1%, p < 0.05). GCAs harbored more frequent mutations in ERBB2 and ERBB3 (9% vs 1%, and 10% vs 0.5%, both p < 0.01) compared to PAs, and in CDKN2A (18% vs 1%, p < 0.05) and KRAS (18% vs 6%, p < 0.05) compared to IGAs. GCAs harbor recurrent somatic mutations in cell cycle-related genes and in potentially targetable genes, including ERBB2/3. Mutations in genes such as STK11 may be used as supportive evidence to help distinguish GCAs from other adenocarcinomas with similar morphology in metastatic sites.

Reproducibility of scoring criteria for HER2 immunohistochemistry in endometrial serous carcinoma: a multi-institutional interobserver agreement study

Targeted anti-human epidermal growth factor receptor 2 (HER2) therapy has recently been proven to improve progression-free and overall survival of patients with advanced stage or recurrent endometrial serous carcinoma. To date, no specific pathology HER2 testing or scoring guidelines exist for endometrial cancer. However, based on evidence from the recent successful clinical trial and comprehensive pre-trial pathologic studies, a new set of HER2 scoring criteria have been proposed for endometrial serous carcinoma-distinct from the existing breast and gastric cancer-specific criteria. We present the first study assessing interobserver agreement of HER2 scores using the proposed serous endometrial cancer-specific scoring system. A digitally scanned set of 40 HER2-immunostained slides of endometrial serous carcinoma were sent to seven gynecologic pathologists, who independently assigned HER2 scores for each slide following a brief tutorial. Follow-up fluorescent in situ hybridization (FISH) for HER2 gene amplification was performed on cases with interobserver disagreement when a 2+ HER2 score was assigned by at least one observer. Complete agreement of HER2 scores among all 7 observers was achieved on 15 cases, and all but one case had an agreement by at least 4 observers. The overall agreement was 72.3% (kappa 0.60), 77.5% (kappa 0.65), and 83.3% (kappa 0.65), using four (0 to 3+ ), three (0/1+ , 2+ , 3+ ), or two (0/1+ , 2/3+ ) HER2 scoring categories, respectively. Based on the combination of HER2 immunostaining scores and FISH, the interobserver disagreement may have potentially resulted in a clinically significant difference in HER2 status only in three tumors. We conclude, that the proposed serous endometrial cancer-specific HER2 scoring criteria are reproducible among gynecologic pathologists with moderate to substantial interobserver agreement rates comparable to those of previously reported in breast and gastric carcinomas. Our findings significantly strengthen the foundation for establishing endometrial cancer-specific HER2 scoring guidelines in the future.

Analysis of the immune checkpoint V-domain Ig-containing suppressor of T-cell activation (VISTA) in endometrial cancer

V-domain Ig-containing suppressor of T-cell activation (VISTA) is a novel immune checkpoint protein and a potential immunotherapeutic target. However, its expression in endometrial cancer has not been clearly defined. This study aimed to investigate VISTA expression and determine its associations with clinicopathological features, molecular subtypes, programmed cell death-ligand 1 (PD-L1) expression, CD8+ T-cell count, and survival in a cohort of 839 patients with endometrial cancer. Using direct sequencing of the polymerase epsilon (POLE) exonuclease domain and immunohistochemistry for mismatch repair (MMR) proteins and p53, we stratified endometrial cancers into four molecular subtypes: POLE ultramutated, MMR-deficient, p53-mutant, and nonspecific molecular profile (NSMP). PD-L1, CD8, and VISTA were detected via immunohistochemistry. VISTA was expressed in the immune cells of 76.6% (643/839) of the samples and in the tumor cells of 6.8% (57/839). VISTA positivity in the immune cells was frequent in tumors staged I-III, those with positive PD-L1 or high CD8+ T-cell density, and those representing POLE ultramutated and MMR-deficient subtypes. Furthermore, VISTA positivity in tumor cells was more frequent in clear cell carcinoma samples. VISTA in immune cells was associated with improved survival in the entire cohort as well as in the endometrioid histology, stage I, PD-L1-negative, MMR-deficient, MMR-proficient, and high and low number of CD8+ T-cell-infiltrated tumor subgroups. VISTA in immune cells was a prognostic factor overall, as well as in patients with endometrioid histology, independent of molecular subtype or CD8+ T-cell density. The data produced by this study, which was the largest to focus on VISTA expression in patients with endometrial cancer to date, suggest that VISTA is a predictor of improved survival.

Clinicopathological significance of deficient DNA mismatch repair and MLH1 promoter methylation in endometrioid endometrial carcinoma

The pathogenesis of DNA mismatch repair (MMR)-deficient endometrial carcinoma (EC) is driven by inactivating methylation or less frequently mutation of an MMR gene (MLH1, PMS2, MSH2, or MSH6). This study evaluated the prognostic and clinicopathologic differences between methylation-linked and nonmethylated MMR-deficient endometrioid ECs. We performed MMR immunohistochemistry and methylation-specific multiplex ligation-dependent probe amplification, and classified 682 unselected endometrioid ECs as MMR proficient (MMRp, n = 438) and MMR deficient (MMRd, n = 244), with the latter subcategorized as methylated (MMRd Met) and nonmethylated tumors. Loss of MMR protein expression was detected in 35.8% of the tumors as follows: MLH1 + PMS2 in 29.8%, PMS2 in 0.9%, MSH2 + MSH6 in 1.3%, MSH6 in 2.8%, and multiple abnormalities in 0.9%. Of the 244 MMRd cases, 76% were methylation-linked. MMR deficiency was associated with older age, high grade of differentiation (G3), advanced stage (II-IV), larger tumor size, abundant tumor-infiltrating lymphocytes, PD-L1 positivity in immune cells and combined positive score, wild-type p53, negative L1CAM, ARID1A loss, and type of adjuvant therapy. MMRd-Met phenotype correlated with older age and larger tumor size, and predicted diminished disease-specific survival in the whole cohort. In the MMRd subgroup, univariate analysis demonstrated an association between disease-specific survival and disease stage II-IV, high grade (G3), deep myometrial invasion, lymphovascular invasion, ER negativity, and L1CAM positivity. In conclusion, MMR methylation profile correlates with clinicopathologic characteristics of endometrioid EC, and MMRd-Met phenotype predicts lower disease-specific survival. MMR deficiency, but not MLH1 methylation status, correlates with T-cell inflammation and PD-L1 expression.

A Distinctive DICER1-Related Wilms-Like Uterine Tumor: A Report of Eight Cases

The presence of DICER1 mutations associated with overlapping morphologic features in tumors arising at different sites has been suggested to define an emerging category of DICER1-related neoplasms. We undertook a clinicopathologic and molecular characterization of uterine tumors originally diagnosed as Wilms tumors to ascertain if they belong to the spectrum of DICER1-related neoplasms. Of 8 patients with a median age of 36.5 (17-69) years, 5 underwent hysterectomy, 2 endometrial curettings, and 1 polypectomy. Most tumors were centered in the endometrium, and 6 were polypoid with a median size of 8 (3.5-16) cm. All showed a variable admixture of primitive mesenchyme and epithelial-like elements set in a hypocellular, edematous to focally myxoid stroma. The epithelial-like elements were the most extensive component, showing a lobular arrangement, including variably sized and shaped primitive tubules with focal confluent/solid growth and cribriforming, as well as glomeruloid and rosette-like structures. Some primitive tubules had intraluminal projections in 3 tumors, imparting an adenosarcoma-like appearance. Scattered glands with fetal-type epithelium were seen in 7 tumors. Rhabdomyosarcomatous differentiation was present in 6 tumors, and neuroectodermal differentiation and fetal-type cartilage in 3 tumors each (including 2 with both features). DICER1 sequencing was successful in 5 of 6 tumors tested, with 4 harboring DICER1 mutations, including all 3 with neuroectodermal differentiation and adenosarcoma-like foci. Fetal-type cartilage was present in 2 of 4 DICER1-mutant tumors and 1 tumor with unknown DICER1 status. Follow-up was available for 6 patients. The patient with DICER1 wild-type tumor (associated with low-grade endometrial endometrioid carcinoma and KRAS mutation) died of disease at 9 months. Of 4 patients with DICER1-mutant tumors, 1 recurred at 7.5 months, 2 were alive without disease at 12 and 38 months, respectively, and 1 was alive with unknown disease status at 31 months. Another patient with unknown DICER1 status was alive at 196 months. Uterine tumors diagnosed as Wilms tumors belong to the spectrum of DICER1-related neoplasms at this site and are best described as a "DICER1-related Wilms-like uterine tumor." These unique tumors are likely part of the larger category of "DICER1-related primitive polyphenotypic neoplasm," warranting further studies.

Prognostic impact of tumor budding in endometrial carcinoma within distinct molecular subgroups

Tumor budding is a robust prognostic parameter in several tumor entities but is rarely investigated in endometrial carcinoma. We applied the recently standardized counting method from the International Tumor Budding Consensus Conference for colorectal cancer (ITBCC) on a cohort of 255 endometrial carcinomas with known molecular profiles according to The Cancer Genome Atlas (TCGA) subgroups. Our investigation aims to clarify the potential prognostic role of tumor budding in endometrial carcinoma in contrast to other known prognostic factors, including molecular factors. In addition, the microcystic elongated and fragmented (MELF) pattern and tumor budding were compared with respect to their potential as markers for epithelial-mesenchymal transition (EMT). Tumor budding was found in n = 67 (26.3%) tumors, with a very low mean of 0.7 buds per ×20 HE field. Tumor budding was significantly associated with depth of invasion, nodal status, lymphatic invasion (each p < 0.001), grading (p = 0.004), and vascular invasion (p = 0.01). Tumor budding showed moderate inter-observer-variability with prognostic stratification irrespective of the observer (κ-value = 0.448). In multivariate analysis, tumor budding served as a significant independent prognosticator for worse outcomes in overall and recurrence-free survival (HR 2.376 and 2.736, p < 0.001), but not when the TCGA subgroups entered into the analysis. In consequence, dependency had to be clarified in the subgroup analysis for Polymerase E mutated (POLEmut), mismatch repair deficient (MMRdef), nonspecific mutation profile (NSMP), and P53 aberrant (P53abn) endometrial carcinomas. A particular impact was identified in the intermediate prognostic groups of NSMP and MMRdef carcinomas. Tumor budding outperformed the MELF pattern in single and combined prognostic information. In conclusion, the presence of tumor budding alone is a promising, robust, and easy-to-apply prognostic parameter in endometrial carcinoma. In a morpho-molecular approach, it exerts its prognostic potential in the most clinically relevant subgroups of endometrial carcinoma and serves as a good biomarker for EMT.

HER2 testing of gynecologic carcinosarcomas: tumor stratification for potential targeted therapy

A recent phase II clinical trial showed increased progression-free survival in patients with HER2-positive endometrial serous carcinoma receiving trastuzumab in addition to carboplatin-paclitaxel chemotherapy. Similar to endometrial serous carcinomas, carcinosarcomas of the female genital tract have a dismal prognosis and could potentially benefit from new targeted therapeutic approaches. We aimed to systematically evaluate the characteristics of HER2 expression/amplification in gynecologic carcinosarcomas using standardized staining methods and scoring criteria. Tumors from 80 patients (65 uterine, 15 tubo-ovarian) were included, containing a serous (60%), endometrioid (10%), clear cell (3%), undifferentiated (3%), neuroendocrine (1%), or mixed (24%) carcinoma, and either a homologous (46%), or a heterologous (54%) sarcoma component. HER2 scores were assigned to both components per the 2007 and 2013 ASCO/CAP breast scoring criteria. A total of 13 cases (12 uterine, 1 ovarian, 16%) were HER2 positive (either by immunohistochemistry or FISH) using the 2013 criteria, while only 10 cases (9 uterine, 1 ovarian, 13%) were HER2 positive per the 2007 criteria. Nine cases showed a change in their HER2 immunohistochemical score between the two scoring systems, including two cases with a change in the overall HER2 status from negative (2007) to positive (2013). Heterogeneity of HER2 protein expression was observed in 38% of HER2-positive tumors, and a lateral/basolateral membranous staining pattern was common. The sarcoma component showed 2+, equivocal HER2 expression in five cases, one of which also demonstrated HER2 amplification by FISH. All HER2-positive carcinosarcomas had either a serous or a mixed carcinoma component, and all but one HER2-positive tumors were of uterine primaries. Our study demonstrates that gynecologic carcinosarcomas share similarities in their HER2 expression/amplification profiles to endometrial serous carcinomas, which should be taken into account when assessing their HER2 status to ensure appropriate patient selection for potential targeted HER2-based therapies in the future.

Retinoblastoma Protein Loss in p53 Abnormal Endometrial Carcinoma: Histologic and Clinicopathological Correlates

Of the 4 molecular subtypes of endometrial cancer (EC), p53-abnormal (p53abn) EC is associated with abundant copy number alterations and the worst clinical outcome. Patients with p53abn EC have the highest risk of disease recurrence and death, independent of tumor grade and histologic subtype. Currently, all invasive p53abn ECs are considered high risk, and no prognostic biomarkers have yet been found that can aid in clinical management. Here, we aimed to test whether loss of retinoblastoma (RB) protein expression using immunohistochemistry has the potential for prognostic refinement of p53abn EC. A large cohort of 227 p53abn ECs collected from the PORTEC-1/2/3 clinical trials and the Medisch Spectrum Twente cohort study was investigated, and RB loss was identified in 7.0% (n = 16/227). RB-lost p53abn ECs were predominantly high-grade endometrioid ECs (n = 6, 37.5%) and carcinosarcomas with endometrioid-type epithelial component (n = 5, 31.3%). Histologically, RB-lost p53abn ECs were typified by high-grade nuclear atypia (n = 16, 100%), predominantly solid growth pattern (n = 15/16, 93.8%), and polypoid growth (n = 9/16, 56.3%). Copy number loss involving the RB1 locus was identified in the majority of RB-lost p53abn EC (n = 13/14, 92.9%), explaining the loss of RB expression. Comparative analysis also showed that RB-lost p53abn ECs were diagnosed at earlier stages than RB-retained p53abn EC (P = .014). Interestingly, RB-lost p53abn EC showed prolonged time to overall recurrence (P = .038), even within stage I alone (P = .040). These findings highlight distinct morphomolecular features in RB-lost p53abn ECs and confirm the utility of RB immunohistochemistry as a surrogate for underlying molecular RB1 alterations. To our knowledge, this is the first study to show the potential use of RB in prognostic refinement of p53abn EC, although validation is warranted.

Primary Mucinous Tumors of the Ovary: An Interobserver Reproducibility and Detailed Molecular Study Reveals Significant Overlap Between Diagnostic Categories

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms, and their diagnosis may be challenging. We analyzed 124 primary ovarian mucinous tumors originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and the potential for diagnostic support by molecular profiling using a next-generation sequencing targeted panel of 727 DNA and 147 RNA genes. Fourteen experienced pathologists independently assigned a diagnosis from preset options, based on a review of a single digitized slide from each tumor. After excluding 1 outlier participant, there was a moderate agreement in diagnosing the 124 cases when divided into 3 categories (κ = 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT as a combined category and MC was found in only 36.3% of the cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic. After a reclassification of the tumors into near-consensus diagnostic categories on the basis of the initial participant results, a comparison of molecular findings between the MBT and MC groups did not show major and unequivocal differences between MBTs and MCs or between MCs with expansile vs infiltrative pattern of invasion. In contrast, HER2 overexpression or amplification was found only in 5.3% of MBTs and in 35.3% of all MCs and in 45% of MCs with expansile invasion. Overall, HER2 alterations, including mutations, were found in 42.2% of MCs. KRAS mutations were found in 65.5% and PIK3CA mutations in 6% of MCs. In summary, although the diagnostic criteria are well-described, diagnostic agreement among our large group of experienced gynecologic pathologists was only moderate. Diagnostic categories showed a molecular overlap. Nonetheless, molecular profiling may prove to be therapeutically beneficial in advanced-stage, recurrent, or metastatic MCs.

Germline Pathogenic Variants in Patients with Pancreatic Ductal Adenocarcinoma and Extra-Pancreatic Malignancies: A Nationwide Database Analysis

Spatial Profiling of Ovarian Clear Cell Carcinoma Reveals Immune-Hot Features

Ovarian clear cell carcinoma (OCCC) has a high incidence in Asia, with a frequent occurrence at an early stage, but without sufficient data on molecular stratification for high-risk patients. Recently, immune-hot features have been proposed as indicators of poor prognosis in early stage OCCC. Specific patterns of intratumoral heterogeneity associated with immune-hot features must be defined. NanoString Digital Spatial Profiling technology (Cold spring biotech corp.) was used to decipher the spatial distribution of the 18-plex protein panel. Regions of interest (ROIs) were collected based on the reference hematoxylin and eosin-stained morphology. Areas of illumination (AOIs) were defined according to the ROI segmentation using the fluorescence signals of the visualization markers pan-cytokeratin (PanCK), CD45, or DNA. Unsupervised hierarchical clustering of 595 AOIs from 407 ROIs showed that the PanCK segments expressed different combinations of immune markers, suggestive of immune mimicry. The following 3 immune-hot clusters were identified: granzyme B-high, immune signal-high , and immune-like cells; the following 2 immune-cold clusters were identified: fibronectin-high and immune checkpoint-high cells. In tumor samples at the International Federation of Gynecology and Obstetrics stage IC1/2 experiencing recurrence, there was an increased occurrence of PanCK+ AOIs with immune signal-high and immune-like cell groups in the papillary morphology surrounded by macrophage lineage tumor-infiltrating immune cells (TIIs). In contrast, for tumor samples at the International Federation of Gynecology and Obstetrics stage IC3/II with recurrence, PanCK+ AOIs were prevalent in the fibronectin-high group, particularly in those with a tubulocystic morphology surrounded by lymphoid lineage non-TIIs. Our study on the spatial profiling of early stage OCCC tumors revealed that the immune mimicry of tumor cells, presence of TIIs, and morphologic patterns were associated with recurrence, which switched during tumor progression.

Molecular and Clinicopathologic Characterization of Mismatch Repair-Deficient Endometrial Carcinoma Not Related to MLH1 Promoter Hypermethylation

Universal tumor screening in endometrial carcinoma (EC) is increasingly adopted to identify individuals at risk of Lynch syndrome (LS). These cases involve mismatch repair-deficient (MMRd) EC without MLH1 promoter hypermethylation (PHM). LS is confirmed through the identification of germline MMR pathogenic variants (PV). In cases where these are not detected, emerging evidence highlights the significance of double-somatic MMR gene alterations as a sporadic cause of MMRd, alongside POLE/POLD1 exonuclease domain (EDM) PV leading to secondary MMR PV. Our understanding of the incidence of different MMRd EC origins not related to MLH1-PHM, their associations with clinicopathologic characteristics, and the prognostic implications remains limited. In a combined analysis of the PORTEC-1, -2, and -3 trials (n = 1254), 84 MMRd EC not related to MLH1-PHM were identified that successfully underwent paired tumor-normal tissue next-generation sequencing of the MMR and POLE/POLD1 genes. Among these, 37% were LS associated (LS-MMRd EC), 38% were due to double-somatic hits (DS-MMRd EC), and 25% remained unexplained. LS-MMRd EC exhibited higher rates of MSH6 (52% vs 19%) or PMS2 loss (29% vs 3%) than DS-MMRd EC, and exclusively showed MMR-deficient gland foci. DS-MMRd EC had higher rates of combined MSH2/MSH6 loss (47% vs 16%), loss of >2 MMR proteins (16% vs 3%), and somatic POLE-EDM PV (25% vs 3%) than LS-MMRd EC. Clinicopathologic characteristics, including age at tumor onset and prognosis, did not differ among the various groups. Our study validates the use of paired tumor-normal next-generation sequencing to identify definitive sporadic causes in MMRd EC unrelated to MLH1-PHM. MMR immunohistochemistry and POLE-EDM mutation status can aid in the differentiation between LS-MMRd EC and DS-MMRd EC. These findings emphasize the need for integrating tumor sequencing into LS diagnostics, along with clear interpretation guidelines, to improve clinical management. Although not impacting prognosis, confirmation of DS-MMRd EC may release patients and relatives from burdensome LS surveillance.

Discordant Staining Patterns and Microsatellite Results in Tumors of MSH6 Pathogenic Variant Carriers

Diagnosis of Lynch syndrome (LS) caused by a pathogenic germline MSH6 variant may be complicated by discordant immunohistochemistry (IHC) and/or by a microsatellite stable (MSS) phenotype. This study aimed to identify the various causes of the discordant phenotypes of colorectal cancer (CRC) and endometrial cancer (EC) in MSH6-associated LS. Data were collected from Dutch family cancer clinics. Carriers of a (likely) pathogenic MSH6 variant diagnosed with CRC or EC were categorized based on an microsatellite instability (MSI)/IHC test outcome that might fail to result in a diagnosis of LS (eg, retained staining of all 4 mismatch repair proteins, with or without an MSS phenotype, and other staining patterns). When tumor tissue was available, MSI and/or IHC were repeated. Next-generation sequencing (NGS) was performed in cases with discordant staining patterns. Data were obtained from 360 families with 1763 (obligate) carriers. MSH6 variant carriers with CRC or EC (n = 590) were included, consisting of 418 CRCs and 232 ECs. Discordant staining was reported in 77 cases (36% of MSI/IHC results). Twelve patients gave informed consent for further analysis of tumor material. Upon revision, 2 out of 3 MSI/IHC cases were found to be concordant with the MSH6 variant, and NGS showed that 4 discordant IHC results were sporadic rather than LS-associated tumors. In 1 case, somatic events explained the discordant phenotype. The use of reflex IHC mismatch repair testing, the current standard in most Western countries, may lead to the misdiagnosis of germline MSH6 variant carriers. The pathologist should point out that further diagnostics for inheritable colon cancer, including LS, should be considered in case of a strong positive family history. Germline DNA analysis of the mismatch repair genes, preferably as part of a larger gene panel, should therefore be considered in potential LS patients.

A comparative study of RTK gene status between primary tumors, lymph-node metastases, and Krukenberg tumors

Krukenberg tumor (KT) refers to a rare ovarian tumor that has metastasized from a primary site. Patients with KTs have a poorer prognosis and worse survival. Thus far, little is known about the frequency of receptor tyrosine kinase (RTK) gene amplification and the concordance of gene amplification between primary tumors, lymph-node metastases, and KTs. Herein, 50 paired samples, including primary cancers, metastatic lymph nodes, and KTs were collected, and RTK gene amplification was tested by fluorescence in situ hybridization (FISH). There were four cases positive for human epidermal growth factor receptor type 2 (HER2) amplification, all of which showed conversion of HER2 status between different lesions. Of the two cases with c-mesenchymal-epithelial transition (c-MET) amplification, the primary tumors and lymph nodes were negative while the right involved ovaries were positive. Inconsistent fibroblast growth factor receptor 2 (FGFR2) status in different lesions was observed in three of the six FGFR2-amplified cases. Co-amplification of RTK genes was identified in only one patient for primary cancer and two for KTs. Collectively, there were 46, 48, 50, and 44 cases negative for HER2, c-MET, EGFR, and FGFR2 amplification in all lesions, respectively. There was no significant difference in overall survival between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin. In conclusion, the positive rate of RTK gene amplification in KTs was low. Intratumoral heterogeneity was frequent in KTs with RTK gene amplification. A mutually exclusive pattern of RTK gene amplification was dominant in primary cancers, lymph-node metastases, and KTs. There was no survival difference between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin.

Automated Prognostic Assessment of Endometrial Hyperplasia for Progression Risk Evaluation Using Artificial Intelligence

Endometrial hyperplasia is a precursor to endometrial cancer, characterized by excessive proliferation of glands that is distinguishable from normal endometrium. Current classifications define 2 types of EH, each with a different risk of progression to endometrial cancer. However, these schemes are based on visual assessments and, therefore, subjective, possibly leading to overtreatment or undertreatment. In this study, we developed an automated artificial intelligence tool (ENDOAPP) for the measurement of morphologic and cytologic features of endometrial tissue using the software Visiopharm. The ENDOAPP was used to extract features from whole-slide images of PAN-CK

Endometrial polyps—neoplastic lesions or not? Is it time to close the files?

CD274 (PD-L1), CDKN2A (p16), TP53, and EGFR immunohistochemical profile in primary, recurrent and metastatic vulvar cancer

Vulvar squamous cell carcinoma can be divided by human papillomaviruses (HPV) status into two distinct clinicopathological and molecular entities. New agents targeting the tumor surface expression of programmed cell death-1/programmed cell death-ligand-1 are becoming a therapeutic option in an increasing number of carcinomas. We evaluate CD274 (PD-L1), CDKN2A (p16), tumor protein p53 (TP53), and epidermal growth factor receptor (EGFR) immunoexpression in primary tumors, recurrences and lymph node metastases and its correlations with prognosis and HPV status. We report 93 cases of vulvar squamous cell carcinoma diagnosed between 2002 and 2016 with the description of their clinicopathological features and prognosis data. Immunohistochemistry for CD274, CDKN2A, TP53, and EGFR was performed on tissue microarrays collecting from primary tumor, recurrences and lymph node metastasis. Kaplan-Meier estimator and multivariable Cox regression analysis controlling for FIGO stage and age were used. Patients who underwent surgery had a superior overall survival (HR = 0.51, 95% CI = 0.26-0.99 p = 0.04). Lymph node metastasis size ≥5 mm was associated with an inferior overall survival (HR = 1.88, 95% CI = 1.22-2.92 p = 0.004). CDKN2A expression was correlated with an inferior rate of recurrent disease (p = 0.02). In high-risk HPV DNA+ vulvar squamous cell carcinomas patients with CDKN2A- carcinomas showed a significantly worse overall survival than women with CDKN2A+ tumors (56% vs.100%, p = 0.003). TP53 expression was associated with an increased rate of recurrent disease (p = 0.0005). CD274 expression was associated with lymph node metastasis (p = 0.04). In 16 patients the CD274, CDKN2A, TP53, and EGFR expression changed between primary tumors, recurrences and lymph node metastases during tumor progression. In conclusion, a significant percentage of vulvar squamous cell carcinoma has a heterogeneous biomarker expression during tumor progression. We highlight the importance of some of these markers to be used as prognostic biomarkers. This data brings new light to future treatment using targeted therapy to EGFR or CD274 to include retesting such biomarkers in recurrence and lymph nodes metastases.

Expanding the spectrum of dicer1-associated sarcomas

DICER1 syndrome is a hereditary cancer predisposition syndrome caused by deleterious germline DICER1 mutations. Characteristic "hotspot" somatic mutations of DICER1 have been identified in DICER1-associated tumors. With the exception of genitourinary embryonal rhabdomyosarcoma and anaplastic sarcoma of the kidney, sarcomas are rarely reported in DICER1 syndrome. Herein, we report the clinical, histopathologic, and molecular findings of a germline DICER1-associated ovarian sarcoma in a 5-year-old female, a somatic DICER1-associated metastatic peritoneal sarcoma in a 16-year-old female, and a somatic DICER1-associated primary intracranial sarcoma in a 4-year-old male. A comprehensive review of the literature, including 83 DICER1-associated sarcomas, illustrates an unequivocal histologic pattern mimicking pleuropulmonary blastoma, regardless of the site of origin. The features include undifferentiated small round blue cells, poorly differentiated spindle cells, and large bizarre pleomorphic cells (anaplasia), often with rhabdomyoblastic and/or chondroid differentiation, and rare bone/osteoid formation. This unique heterogeneous histologic pattern should raise suspicion for pathogenic DICER1 mutation(s) warranting a detailed review of the family history and DICER1 mutation analysis. In addition to expanding the phenotypic spectrum of DICER1-associated conditions, identification of pathogenic DICER1 variants facilitates optimized genetic counseling, caregiver education and judicious imaging-based surveillance.

Natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions

High-grade serous carcinoma is the most common and devastating type of ovarian cancer; its etiology, mechanism of malignant transformation, and origin remain controversial. Recent studies have identified secretory cells at the fimbria of the fallopian tube as the cell-of-origin of high-grade serous carcinoma, acquiring TP53 mutation, evolving to tubal precursor lesions, including "p53 signature" and serous tubal intraepithelial carcinoma, and metastasizing to the ovary as clinically evident ovarian cancer. The etiological mechanisms associated with known epidemiological risk factors, i.e., ovulation and retrograde menstruation, have also been suggested. Mutagens and transforming growth factors, such as reactive oxygen species and insulin-like growth factor axis proteins, as well as the apoptosis-rescuing protein hemoglobin are abundantly present in the ovulatory follicular fluid and peritoneum fluid, which bathes the fimbrial epithelium, and induces malignant transformation after repeated exposure. In accordance with the proposed cleansing effect of progesterone from studies on oral contraceptive use or term pregnancy, a recent study indicated that the p53-null tubal epithelial cells are selectively cleared by progesterone depending on its progesterone receptor. In this report, by analyzing different time effects of oral contraceptive use or pregnancy in the prevention of ovarian cancer and by aligning them with the carcinogenic and cleansing clearance concepts of ovulation and progesterone, as well as the fact of progressive loss of progesterone receptor during tubal transformation, we deduced the natural history of ovarian high-grade serous carcinoma. The natural history begins at the first ovulation and spans for more than 30 years, taking 10 years from the normal tubal epithelium to the "p53 signature" status, another 15 years to progesterone receptor negative serous tubal intraepithelial carcinoma, and a final 5+ years to high-grade serous carcinoma. The estimated natural history may help understand the pathogenesis of high-grade serous carcinoma and defines the window for early detection and chemoprevention.

Deep Learning Predicts Survival Across Squamous Tumor Entities From Routine Pathology: Insights From Head and Neck, Esophagus, Lung, and Cervical Cancer

Computational pathology-based models are becoming increasingly popular for extracting biomarkers from images of cancer tissue. However, their validity is often only demonstrated on a single unseen validation cohort, limiting insights into their generalizability and posing challenges for explainability. In this study, we developed models to predict overall survival using hematoxylin and eosin slides from formalin-fixed paraffin-embedded samples in head and neck squamous cell carcinoma. By validating our models across diverse squamous tumor entities, including head and neck (hazard ratio [HR], 1.58; 95% CI, 1.17-2.12; P = .003), esophageal (nonsignificant), lung (HR, 1.31; 95% CI, 1.13-1.52; P < .001), and cervical (HR, 1.39; 95% CI, 1.10-1.75; P = .005) squamous cell carcinomas, we showed that the predicted risk score captures relevant information for survival beyond head and neck squamous cell carcinoma. Correlation analysis indicated that the predicted risk score is strongly associated with various clinical factors, including human papillomavirus status, tumor volume, and smoking history, although the specific factors vary across cohorts. These results emphasize the relevance of comprehensive validation and in-depth assessment of computational pathology-based models to better characterize the underlying patterns they learn during training.

Attention-Based Whole-Slide Image Compression Achieves Pathologist-Level Prescreening of Multiorgan Routine Histopathology Biopsies

Screening programs for the early detection of cancers, such as colorectal and cervical cancers, have led to an increased demand for histopathological analysis of biopsies. Advanced image analysis with deep learning has shown the potential to automate cancer detection in digital pathology whole-slide images. In particular, weakly supervised learning can achieve whole-slide image classification without the need for tedious, manual annotations, using only slide-level labels. Here, we used data from n = 12,580 whole-slide images from n = 9141 tissue blocks to train and validate a weakly supervised deep learning approach based on Neural Image Compression with Attention (NIC-A) using labels extracted from pathology reports. We also introduced slide packing, a method that merges tissue from multiple slides of the same tissue block into a single "packed" image linked to block-level labels. NIC-A classifies colon and cervical tissue slides into cancer, high-grade dysplasia, low-grade dysplasia, and normal tissue and detects celiac disease in duodenal biopsies. We validated NIC-A for colon and cervix against panels of 4 and 3 pathologists, respectively, on cohorts from 2 European centers. We show that the proposed approach reaches pathologist-level performance in detecting and classifying abnormalities, suggesting its potential to assist pathologists in prescreening workflows by reducing workload in routine digital pathology diagnostics.

Whole Slide Imaging-Free Supporting Tool for Cytotechnologists in Cervical Cytology

Cervical cytology is a crucial method for detecting cancerous and precancerous lesions. However, traditional workflows rely heavily on manual microscopic observations by cytotechnologists, making the process time-consuming and labor-intensive. Although several artificial intelligence (AI)-assisted cytology systems have been developed, most approaches require whole slide images, which entails costly scanning equipment, extensive data storage, and additional processing time. These factors hinder real-time diagnosis and are often impractical in resource-limited settings. In this study, we developed cytology-all-in-one (CYTOLONE), a novel AI model designed to support cytotechnologists in cervical cytology. CYTOLONE was constructed using a model based on OpenAI's contrastive language-image pretraining framework and fine-tuned using a hierarchical labeling structure. This approach enabled the model to effectively learn the relationship between low-magnification images and cytologic features. By integrating the microscope directly with an Apple Silicon Mac and using an iPhone camera for image capture, CYTOLONE offers real-time evaluation, processing each image in under 0.5 seconds. The evaluation results demonstrated that CYTOLONE achieved superior classification accuracy compared with both contrastive language-image pretraining-ViT-B/16 and GynAIe-B16-10k. The model maintained high Anomaly detection accuracy (95.8%) and significantly improved accuracy in Malignancy (92.8%), Bethesda (61.5%), and Diagnosis (57.5%) categories. Furthermore, feature space visualization revealed clearer boundaries between diagnostic categories, reflecting CYTOLONE's improved performance. The proposed workflow seamlessly integrates traditional cytology practices, allowing cytotechnologists to receive AI support during real-time specimen observation. This innovative workflow eliminates the need for costly whole slide image scanners, improves diagnostic efficiency, and is well-suited for resource-limited environments. Our findings suggest that CYTOLONE can enhance the efficiency of cytotechnologists and improve diagnostic accuracy, offering a practical solution to the existing limitations in AI-assisted cytology systems.

Should screening for cervical cancer go to primary human papillomavirus testing and eliminate cytology?

This review will systematically highlight the pros and cons of cervical cancer screening with HPV (human papillomavirus) testing and cytological methods (Papanicolaou (Pap) test). When comparing the screening modalities, various facets will be addressed, such as cost effectiveness, and harms and benefits across different demographics and age groups. It is important to note that due to the expansive variance in material costs, practices, and resource availability across different geographical regions, these comparisons are far from straight forward, and ultimately make it challenging to render definitive global recommendations. Thus, the intent of this review is to highlight some of the differences in difference cervical cancer screening modalities that can help one to choose an optimal screening method in their specific situation.

Methylation Analysis to Detect CIN3+ in High-Risk Human Papillomavirus-Positive Self-Samples From the Population-Based Cervical Cancer Screening Program

Since 2017, a self-sampling device has been introduced to the Dutch population-based screening program to enable higher participation rates. However, routine triage cytology cannot be performed on self-sampling material. Methylation is an alternative triage method that can be performed directly on DNA extracted from self-samples. Recently, we tested a set of 15 published cervical intraepithelial neoplasia grade 3 or worse (CIN3+)-specific methylation markers and found a panel of 3 markers with a sensitivity of 82% and a specificity of 74%. In this study, we determined the sensitivity and specificity of 2 commercial assays using quantitative methylation-specific PCR. DNA from the same cohort of high-risk human papillomavirus-positive self-sampled material obtained through the population-based screening program in the North of the Netherlands from women with CIN2 or less (<CIN3, n = 208) and women with CIN3+ (n = 96) was used. The QIAsure methylation test (consisting of 2 methylation markers) showed a sensitivity of 65% and a specificity of 72%, whereas the Gyntect assay (consisting of 6 methylation markers) showed a sensitivity of 59% and a specificity of 91% for CIN3+. When we compared all individual 23 methylation markers, receiver operating characteristic analysis showed an area under the curve of ≥0.7 for 11 of 23 markers (P < .001). By model-based recursive partitioning and robustness analysis, we found a panel with a better sensitivity compared with QIAsure and Gyntect (P < .001). This new panel, consisting of ITGA4, ASCL1, and FAM19A4, has a sensitivity of 84% and a specificity of 70%, similar to our previously identified panel (ANKRD18CP, LHX8, and EPB41L3). Thus, in addition to our previously identified panel, the combination of ITGA4, ASCL1, and FAM19A4 showed good diagnostic performance and potentially can replace cytology, thereby avoiding additional doctor visits for many women worldwide and reducing the time for decision making for referral to the gynecologist.

Pathogenic POLE-Mutated Endometrial Carcinomas With a Nonultramutated Genome

Endometrial carcinomas can be classified into 1 of 4 molecular subtypes, with the POLE-mutant subtype carrying the best prognosis. Pathogenic mutations in POLE are known to disrupt the proofreading function of DNA polymerase epsilon, resulting in an ultramutated genome, typically defined as ≥100 mutations per megabase. Routine next-generation sequencing was implemented on all endometrial carcinoma cases at our institution beginning in December 2023 to aid in molecular subclassification. During this routine sequencing, 6 POLE-mutated cases, with confirmed pathogenic POLE mutations, were observed to have a tumor mutational burden <100; prior to universal testing, only 1 such case had been identified. Endometrial carcinoma cases with pathogenic POLE mutations and tumor mutational burden <100 may be globally under-recognized, as universal testing is not yet a widely standard practice. These cases with pathogenic POLE mutations and a nonultramutated genome were found to have a lower frequency of classic morphologic "POLE features," including high-grade histology, compared with classic ultramutated cases. The immunohistochemical profiles are also different from ultramutated counterparts, with a lower frequency of mismatch repair immunohistochemical abnormalities and p53 null or diffuse staining, and a higher likelihood of strong and diffuse estrogen receptor/progesterone receptor expression, aligning with fewer mutations in encoding genes. However, endometrial carcinoma with pathogenic POLE mutations, without ultramutation, appears to retain the "POLE-mutational signature" described in the literature. Additionally, clinical outcomes do not appear different; however, this phenomenon needs additional investigation.

Clinicopathologic, Immunohistochemical, and Molecular Analysis of Primary Ovarian Carcinoid Tumors With Correlation of Ki67 Proliferation Index With Patient Outcomes

Primary ovarian carcinoid tumors (pOCTs) are a rare subset of ovarian neoplasms resembling well-differentiated neuroendocrine tumors (NETs) arising in the gastrointestinal tract. Unlike NETs at other anatomic sites, the use of proliferation markers, such as mitotic count and Ki67 proliferation index, is not well established in the classification of these tumors. In this study, we describe the clinicopathologic, immunohistochemical, and molecular characteristics of pOCTs and correlate mitotic count and Ki67 index with patient outcomes. In our series of 23 pOCTs, most cases were associated with at least 1 other ovarian neoplasm (19/23; 82.6%), most often a mature teratoma or struma ovarii (each 43.5%; 10/23). All 23 cases (100%) expressed synaptophysin, whereas 87.0% (20/23) expressed chromogranin. Frequent staining with TTF-1 and CDX2 (33.3% and 83.3%, respectively) was also observed. Targeted exome sequencing was performed in 14 cases, which identified no recurrent NET-associated mutations or novel mutations in pOCTs. Most pOCTs presented as stage IA disease (13/23; 56.5%), of which 6 had Ki67 indices >3% (46.2%; 6/13). There were 6 cases of stage IC disease (26.0%), which exhibited a variable Ki67 index (range: 1.2%-35.6%). Extraovarian spread was noted in 4 cases (17.4%), with 3 cases having Ki67 indices >3% (range: 1.0%-58.8%). Local recurrence occurred in 1 case (4.3%) with pelvic sidewall involvement at diagnosis and a Ki67 index of 58.8%. Follow-up, ranging from 3 to 153 months (median: 55.5 months), showed no disease-related deaths. We combined our findings with 16 previously published cases of pOCTs and found that cases with >20 mitoses per 2 mm

Early Genetic Divergence of High-Grade Carcinomas Originating from Low-Grade Serous Ovarian Neoplasms

The current paradigm implicates a fallopian tube precursor as the origin of most ovarian high-grade serous carcinomas (HGSCs). However, a rare subset of HGSCs develop via a distinct pathway from low-grade serous ovarian neoplasms (namely, serous borderline tumors and low-grade serous carcinoma). This alternate pathway for the development of HGSC and other poorly differentiated carcinomas of the ovary is not well understood. To elucidate the molecular pathogenesis and evolutionary trajectory of histologic transformation of low-grade serous neoplasms, we performed whole exome sequencing on microdissected low-grade and higher-grade components from 7 cases of serous borderline tumor or low-grade serous carcinoma associated with a synchronous or metachronous indeterminate/high-grade carcinoma. In most cases, there were relatively few somatic mutations shared between matched low-grade and higher-grade tumors compared with private mutations specific to each component (ie, phylogenetic trees with short trunks and long branches). Truncal mutations, present across all tumor samples from a given patient, included known drivers of low-grade serous neoplasms: KRAS (G12D, n = 4), BRAF (G469A, n = 1), NF2 (n = 1), and USP9X (n = 1). Transformation to HGSC was associated with a TP53 mutation with bi-allelic inactivation in 3 cases, all with severe nuclear atypia, and associated with genome-wide copy number alterations and allelic imbalances. TP53-wildtype tumors comprised a morphologic spectrum, which included indeterminate-grade serous carcinomas with moderate nuclear atypia and high mitotic activity, although lacking extensive chromosomal instability (n = 2) and poorly differentiated carcinomas (n = 2, including a high-grade Mullerian carcinoma and an undifferentiated carcinoma with sarcomatoid features). In summary, synchronous and metachronous low-grade serous neoplasms and higher-grade carcinomas are clonally related. Early genetic divergence, most evident in cases with TP53 mutations, suggests that high-grade transformation may be a relatively early molecular event.

Frequent PIK3CA mutations in eutopic endometrium of patients with ovarian clear cell carcinoma

Recent studies have reported cancer-associated mutations in normal endometrium. Mutations in eutopic endometrium may lead to endometriosis and endometriosis-associated ovarian cancer. We investigated PIK3CA mutations (PIK3CAm) for three hotspots (E542K, E545K, H1047R) in eutopic endometrium in patients with ovarian cancer and endometriosis from formalin-fixed paraffin-embedded specimens by laser-capture microdissection and droplet digital PCR. The presence of PIK3CAm in eutopic endometrial glands with mutant allele frequency ≥ 15% were as follows: ovarian clear cell carcinoma (OCCC) with PIK3CAm in tumors, 20/300 hotspots in 11/14 cases; OCCC without PIK3CAm, 42/78 hotspots in 11/12 cases; high-grade serous ovarian carcinoma, 8/45 hotspots in 3/5 cases; and endometriotic cysts, 5/63 hotspots in 5/6 cases. These rates were more frequent than in noncancer nonendometriosis controls (7/309 hotspots in 5/17 cases). In OCCC without PIK3CAm, 7/12 (58%) cases showed multiple hotspot mutations in the same eutopic endometrial glands. In 3/54 (5.6%) cases, PIK3CAm was found in eutopic endometrial stroma. Multisampling of the OCCC tumors with PIK3CAm showed intratumor heterogeneity in three of eight cases. In two cases, PIK3CAm was detected in the stromal component of the tumor. Homogenous PIK3CAm in the epithelial component of the tumor matched the mutation in eutopic endometrial glands in only one case. Eutopic endometrial glands in ovarian cancer and endometriosis show high frequency of PIK3CAm that is not consistent with tumors, and multiple hotspot mutations are often found in the same glands. While the mutations identified in eutopic endometrium may not be driver mutations in the patient's cancer, these are still driver mutations but this specific clone has not undergone the requisite steps for the development of cancer.

Deriving tumor purity from cancer next generation sequencing data: applications for quantitative ERBB2 (HER2) copy number analysis and germline inference of BRCA1 and BRCA2 mutations

Tumor purity, or the relative contribution of tumor cells out of all cells in a pathological specimen, influences mutation identification and clinical interpretation of cancer panel next generation sequencing results. Here, we describe a method of calculating tumor purity using pathologist-guided copy number analysis from sequencing data. Molecular calculation of tumor purity showed strong linear correlation with purity derived from driver KRAS or BRAF variant allele fractions in colorectal cancers (R

Immunohistochemical and genetic characteristics of HPV-associated endocervical carcinoma with an invasive stratified mucin-producing carcinoma (ISMC) component

Invasive stratified mucin-producing carcinoma (ISMC) is a recently described entity of human papillomavirus (HPV)-associated endocervical adenocarcinoma with phenotypic plasticity and aggressive clinical behavior. To identify the cell of origin of ISMC, we investigated the immunohistochemical expression of cervical epithelial cell markers (CK7, PAX8, CK5/6, p63, and CK17), stemness markers (ALDH1 and Nanog), and epithelial-mesenchymal transition (EMT) markers (Snail, Twist, and E-cadherin) in 10 pure and mixed type ISMCs with at least 10% of ISMC component in the entire tumor, seven usual type endocervical adenocarcinomas (UEAs), and seven squamous cell carcinomas (SCCs). In addition, targeted sequencing was performed in 10 ISMCs. ISMC was significantly associated with larger tumor size (p = 0.011), more frequent lymphovascular invasion and lymph node metastasis (p < 0.001), higher FIGO stage (p = 0.022), and a tendency for worse clinical outcomes (p = 0.056) compared to other HPV-associated subtypes. ISMC showed negative or borderline positivity for PAX8, CK5/6, and p63, which were distinct from UEA and SCC (p < 0.01). Compared to UEA and SCC, ISMC showed higher expression for ALDH1 (p = 0.119 for UEA and p = 0.009 for SCC), Snail (p = 0.036), and Twist (p = 0.119), and tended to show decreased E-cadherin expression (p = 0.083). In next-generation sequencing analysis, ISMC exhibited frequent STK11, MET, FANCA, and PALB2 mutations compared to conventional cervical carcinomas, and genes related to EMT and stemness were frequently altered. EMT-prone and stemness characteristics and peripheral expression of reserve cell and EMT markers of ISMC suggest its cervical reserve cell origin. We recommend PAX8, CK5/6, and p63 as diagnostic triple biomarkers for ISMC. These findings highlight the distinct biological basis of ISMC.

Genetic characteristics of gastric-type mucinous carcinoma of the uterine cervix

Gastric-type mucinous carcinoma (GAS) is a recently established variant of endocervical mucinous adenocarcinoma that is characterized as being unrelated to HPV and having aggressive behavior and chemoresistance. GAS has a distinct morphology resembling nonneoplastic gastric glands or pancreaticobiliary adenocarcinoma, and their possible genetic similarity has been posed. In this study, next-generation sequencing was performed in 21 GAS cases using a customized panel including 94 cancer-associated genes. A total of 54 nonsynonymous somatic mutations were detected with an average mutation rate of 2.6 per lesion (range: 0-9). The most frequently mutated gene was TP53 (11/21, 52.4%), followed by STK11, HLA-B, PTPRS (4/21, 19.0%), FGFR4 (3/21, 14.3%), GNAS, BRCA2, ELF3, ERBB3, KMT2D, SLX4 (2/21, 9.5%), CDH1, EPCAM, KRAS, MLH1, RNF43, SNAI1, TWIST1, ZEB1, ZEB2, and so on (1/21, 4.8%). The mutated genes were mostly involved in signal transduction, DNA damage repair, and epithelial-mesenchymal transition (EMT). Correlation of TP53 mutation and p53 protein expression demonstrated that 31.3% with abnormal p53 expression harbored wild-type TP53. Compared to genetic features of gastric and pancreaticobiliary adenocarcinoma, TP53 mutations were frequent in both GAS and gastrointestinal adenocarcinoma. While KMT2D, ERBB3, and RNF43 mutations were shared between GAS and gastric adenocarcinoma, highly mutated genes in pancreatic ductal adenocarcinoma such as KRAS, SMAD4, and CDKN2A were rarely mutated in GAS. Of frequently mutated genes in cholangiocarcinoma, BAP1 and HLA-B were identified in GAS. Frequent EMT-related gene mutations suggested a possible role of EMT-related pathways in tumor dissemination and chemoresistance of GAS. In addition, GAS shared some genetic features with gastrointestinal adenocarcinoma. These findings provide a clue in understanding the biological basis of GAS.

p53 Immunohistochemical patterns in HPV-related neoplasms of the female lower genital tract can be mistaken for TP53 null or missense mutational patterns

We have recently encountered p53 immunohistochemical (IHC) patterns in human papillomavirus (HPV)-associated carcinomas of the gynecologic tract, which were confused with absent (null) or overexpression TP53 mutational staining. We therefore evaluated p53 and p16 IHC in 25 squamous cell carcinomas (SCC) (16 vulva, 4 Bartholin's gland, and 5 cervix), 20 endocervical adenocarcinomas (EDAC), 14 high-grade squamous intraepithelial lesions (HSIL), 2 adenocarcinoma in situ (AIS), all of which exhibited morphologic features of HPV. Only cases showing diffuse/strong block-like p16 staining were included for further study. All EDACs underwent TP53 sequencing and HPV in situ hybridization (ISH) was performed in selected cases. p53 IHC staining fell into two main patterns. The most common was designated as "markedly reduced (null-like)" (absence or significantly attenuated staining in >70% of cells), which could be confused with true null mutational pattern. This was present in 14/25 (56%) SCCs, 7/14 (50%) HSILs, and 18/20 (90%) EDACs. The second notable pattern was "mid-epithelial (basal sparing)" (distinct absence of staining in basal cells juxtaposed with strong staining in parabasal cells), seen in 10/25 (40%) SCC, 7/14 (50%) HSIL, and none of the EDACs. There was scattered weak to moderate p53 staining (conventional wild type) in 1/25 (4%) SCC and 2/20 (10%) EDAC. No cases showed strong/diffuse overexpression. One EDAC had a TP53 missense mutation and exhibited "markedly reduced (null-like)" staining. HPV ISH revealed an inverse relationship with p53, cells positive for HPV mRNA were negative for p53. Knowledge of these patterns can help pathologists avoid misinterpreting p53 status in the setting of HPVA cancers.

RNA-based high-risk HPV genotyping and identification of high-risk HPV transcriptional activity in cervical tissues

Nearly all cervical cancers are initiated by a persistent infection with one of the high-risk human papillomaviruses (high-risk HPV). High-risk HPV DNA testing is highly sensitive but cannot distinguish between active, productive infections and dormant infections or merely deposited virus. A solution for this shortcoming may be the detection of transcriptional activity of viral oncogenes instead of mere presence of high-risk HPVs. In this study, fresh-frozen cervical tissues (n = 22) were subjected to high-risk HPV DNA detection using the line probe assay and to targeted RNA next-generation sequencing using single-molecule molecular inversion probes. Targeted RNA sequencing was applied for (1) RNA-based genotyping of high-risk HPV, giving information on specific HPV-subtype (2) discrimination of E2, E6, and E7 transcripts and (3) discovery of possible non-HPV cancer biomarkers. Data were analyzed using computational biology. Targeted RNA sequencing enabled reliable genotyping of high-risk HPV subtypes and allowed quantitative detection of E2, E6, and E7 viral gene expression, thereby discriminating cervical lesions from normal cervical tissues. Moreover, targeted RNA sequencing identified possible cervical cancer biomarkers other than high-risk HPV. Interestingly, targeted RNA sequencing also provided high-quality transcription profiles from cervical scrape samples, even after 1 week of dry storage or storage in Preservcyt fixative. This proof of concept study shows that targeted RNA sequencing can be used for high-risk HPV genotyping and simultaneous detection of high-risk HPV gene activity. Future studies are warranted to investigate the potential of targeted RNA sequencing for risk assessment for the development of cervical lesions, based on molecular analysis of cervical scrapes.

Prognostic implications of genotyping and p16 immunostaining in HPV-positive tumors of the uterine cervix

Human papillomaviruses (HPVs) are the causative agents of carcinoma of the uterine cervix. A number of HPV genotypes have been associated with cervical cancer and almost all tumors associated with HPV show strong p16 expression. However, there is little information on the possible impact of the HPV genotype and p16 immunostaining on the clinicopathological features or their prognostic value in cervical carcinoma. We evaluated a series of 194 patients with HPV-positive cervical cancers treated at our institution, focusing on the clinicopathological features and the relationship of the HPV genotypes and p16 immunostaining with the prognosis. A single HPV type was identified in 149 (77%) tumors, multiple HPV infection was detected in 30 cases (15%), and undetermined HPV type/s were identified in 15 (8%) carcinomas. HPV 16 and/or 18 were detected in 156 (80%) tumors. p16 was positive in 186 (96%) carcinomas, but eight tumors (4%) were negative for p16 (seven squamous cell carcinomas, one adenocarcinoma); 5/8 caused by HPV 16 and/or 18. Patients with HPV 16 and/or 18 were younger (49 ± 15 vs. 57 ± 17 years, p < 0.01) and more frequently had nonsquamous tumors than patients with other HPV types (24% [37/156] vs. 0% [0/38]; p = 0.01). Neither the HPV type nor multiple infection showed any prognostic impact. Patients with p16-negative tumors showed a significantly worse overall survival than women with p16-positive carcinomas (45 vs. 156 months, p = 0.03), although no significant differences in disease-free survival were observed. In the multivariate analysis, negative p16 immunostaining was associated with a worse overall survival together with advanced FIGO stage and lymph node metastases. In conclusion, the HPV genotype has limited clinical utility and does not seem to have prognostic value in cervical cancer. In contrast, a negative p16 result in patients with HPV-positive tumors is a prognostic marker associated with a poor overall survival.

GLUT1 Expression Patterns in Verruciform Acanthotic Vulvar Squamous Intraepithelial Neoplasia, HPV–Independent p53 Wild-Type Squamous Cell Carcinoma and Benign Vulvar Lesions

Verruciform acanthotic vulvar intraepithelial neoplasia (vaVIN) is a rare type of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma (SCC) precursor lacking aberrant p53 expression. Our recent study demonstrated GLUT1 overexpression in vulvar SCC and identified 2 distinct patterns in HPV-associated high-grade squamous intraepithelial lesions and HPV-independent differentiated vulvar intraepithelial neoplasia. Herein, we expand on our study by assessing GLUT1 expression in 24 cases of vaVIN and 8 cases of associated invasive SCC, compared with 48 cases of benign vulvar squamous lesions, including 40 cases of non-HPV benign vulvar lesions and 8 cases of condyloma associated with low-risk HPV infection. GLUT1 immunohistochemistry (IHC) demonstrated consistent diffuse GLUT1 immunostaining in all vaVIN cases. The GLUT1 immunostaining pattern in vaVIN is characterized by strong membranous staining in the basal layer with suprabasal extension to the full thickness of intermediate layers. In vulvar SCC associated with vaVIN, GLUT1 expression was prominent at the periphery of tumor nests without expression in the central portion. GLUT1 IHC revealed weak peri-papillae or intensified peri-papillae patterns in non-neoplastic vulvar lesions and HPV-related patterns in condyloma. The GLUT1 immunostaining patterns in vaVIN and associated SCC are different from benign mimickers, but similar to those of differentiated vulvar intraepithelial neoplasia and associated SCC, despite distinct molecular alterations and pathways. The latter suggests that upregulation of GLUT1 is likely a common metabolic pathway shared by 2 types of HPV-independent VINs, regardless of p53 status. GLUT1 IHC is highly sensitive in detecting vaVIN. However, the specificity rests on recognizing GLUT1-staining patterns in benign mimickers of vaVIN. Along with HPV chromogenic in situ hybridization and other well-characterized biomarkers, GLUT1 immunochemistry can be a helpful adjunct in assisting the diagnosis of vaVIN.

Distinct Patterns of GLUT1 Expression in Human Papillomavirus Associated and Human Papillomavirus Independent Vulvar Intraepithelial Neoplasia and Squamous Cell Carcinoma

The expression of GLUT1 in vulvar squamous cell carcinoma (SCC) and its precursors remains largely unknown. We systematically investigated GLUT1 expression in human papillomavirus (HPV)-associated and HPV-independent vulvar intraepithelial neoplasia (VIN) and SCC. Our study had a total of 240 cases, including 40 cases of non-neoplastic vulva, 45 HPV-associated high-grade squamous intraepithelial lesions (HSILs), 65 HPV-independent VINs, and 90 invasive SCCs. Immunohistochemical analysis revealed that GLUT1 was expressed noncontinuously at the basal layer near stromal papillae in most non-neoplastic vulvar squamous epithelium. Overexpression of GLUT1 was observed in 82.2% and 88.9% of HPV-associated HSIL and SCC, respectively, compared with 96.9% and 100% of HPV-independent VIN and SCC. Two distinct patterns of the GLUT1 expression were observed in HPV-associated and HPV-independent VIN and SCC. In HPV-associated HSIL, overexpression of GLUT1 was mainly noted in the upper intermediate layers, accompanied by negative or weak immunostaining in the basal and parabasal layers. Similar patterns were also found in HPV-associated SCC, characterized by increased GLUT1 staining intensity in the centers of tumor sheets or nests with spared basal peripheral layers. Conversely, intense membranous GLUT1 staining was mainly observed in the basal and suprabasal layers in HPV-independent VIN, regardless of p53 status. Similar intense basal and parabasal GLUT1 staining patterns and no or weak staining intensity in central areas were seen in HPV-independent SCCs. In conclusion, overexpression of GLUT1 was found in most vulvar SCCs and their precursors. We identified 2 distinct GLUT1 patterns between HPV-associated and HPV-independent VINs and SCCs. Given its high sensitivity, immunohistochemistry for GLUT1 can be a valuable tool for facilitating accurate diagnosis of VIN, especially the HPV-independent type.

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Classification of Vulvar Squamous Cell Carcinoma and Precursor Lesions by p16 and p53 Immunohistochemistry: Considerations, Caveats, and an Algorithmic Approach

There is emerging evidence that vulvar squamous cell carcinoma (VSCC) can be prognostically subclassified into 3 groups based on human papillomavirus (HPV) and p53 status: HPV-associated (HPV+), HPV-independent/p53 wild-type (HPV-/p53wt), or HPV-independent/p53 abnormal (HPV-/p53abn). Our goal was to assess the feasibility of separating VSCC and its precursors into these 3 groups using p16 and p53 immunohistochemistry (IHC). A tissue microarray containing 225 VSCC, 43 usual vulvar intraepithelial neoplasia (uVIN/HSIL), 10 verruciform acanthotic vulvar intraepithelial neoplasia (vaVIN), and 34 differentiated VIN (dVIN), was stained for p16 and p53. Noncomplementary p16 and p53 patterns were resolved by repeating p53 IHC and HPV RNA in situ hybridization (ISH) on whole sections, and sequencing for TP53. Of 82 p16-positive VSCC, 73 (89%) had complementary p16 and p53 patterns and were classified into the HPV+ group, 4 (4.9%) had wild-type p53 staining, positive HPV ISH and were classified into the HPV+ group, whereas 5 (6.1%) had p53 abnormal IHC patterns (1 null, 4 overexpression), negativity for HPV ISH, and harbored TP53 mutations (1 splice site, 4 missense); they were classified as HPV-/p53abn. Of 143 p16-negative VSCC, 142 (99.3%) had complementary p53 and p16 patterns: 115 (80.4%) HPV-/p53abn and 27 (18.9%) HPV-/p53wt. One had a basal-sparing p53 pattern, positivity for HPV ISH and was negative for TP53 mutations-HPV+ category. The use of IHC also led to revised diagnoses-HSIL to dVIN (3/43), dVIN to vaVIN (8/34), and dVIN to HSIL (3/34). Overall, 215/225 VSCC (95.6%) could be easily classifiable into 3 groups with p16 and p53 IHC. We identified several caveats, with the major caveat being that "double-positive" p16/p53 should be classified as HPV-/p53abn. We propose an algorithm that will facilitate the application of p16 and p53 IHC to classify VSCC in pathology practice.

p53-Abnormal “Fields of Dysplasia” in Human Papillomavirus–Independent Vulvar Squamous Cell Carcinoma Impacts Margins and Recurrence Risk

Abnormal p53 (p53abn) immunohistochemical (IHC) staining patterns can be found in vulvar squamous cell carcinoma (VSCC) and differentiated vulvar intraepithelial neoplasia (dVIN). They can also be found in the adjacent skin that shows morphology that falls short of the traditional diagnostic threshold for dVIN. Vulvectomy specimens containing human papillomavirus-independent p53abn VSCC with margins originally reported as negative for invasive and in situ disease were identified. Sections showing the closest approach by invasive or in situ neoplasia to margins were stained with p53 IHC stains. We evaluated the following: (1) detection of morphologically occult p53abn in situ neoplasia, (2) rates of margin status change after p53 IHC staining, and (3) effect of p53abn IHC staining at margins on the 2-year local recurrence rates. Seventy-three human papillomavirus-independent p53abn VSCCs were included. Half (35/73, 48%) had documented an in situ lesion in the original report. The use of p53 IHC staining identified 21 additional cases (29%) with the p53abn in situ lesions that were originally unrecognized. The histology of in situ lesions in the p53abn "field" varied and became more subtle (morphologically occult) farther away from the VSCC. Fifteen (21%) cases had a morphologically occult and previously unrecognized p53abn in situ lesion present at a resection margin, which conferred an increased risk of local recurrence (5/7 [71.4%] vs 6/22 [27.3%], P = .036). The p53abn in situ lesions at a margin were confirmed to have TP53 mutations by sequencing. p53 IHC staining identified morphologically occult p53abn in situ lesions surrounding human papillomavirus-independent VSCC. p53abn IHC staining at a margin was associated with a 3-fold increased risk of local recurrence.

HPV-independent, p53-wild-type vulvar intraepithelial neoplasia: a review of nomenclature and the journey to characterize verruciform and acanthotic precursor lesions of the vulva

Vulvar squamous cell carcinomas and their precursors are currently classified by the World Health Organization based on their association with high-risk human papillomavirus (HPV). HPV independent lesions often harbor driver alterations in TP53, usually seen in the setting of chronic vulvar inflammation. However, a group of pre-invasive vulvar squamous lesions is independent from both HPV and mutant TP53. The lesions described within this category feature marked acanthosis, verruciform growth and altered squamous maturation, and over the last two decades several studies have added to their characterization. They have a documented association with verrucous carcinoma and conventional squamous cell carcinoma of the vulva, suggesting a precursor role. They also harbor recurrent genomic alterations in several oncogenes, mainly PIK3CA and HRAS, indicating a neoplastic nature. In this review, we provide a historical perspective and a comprehensive description of these lesions. We also offer an appraisal of the terminology used over the years, going from Vulvar Acanthosis with Altered Differentiation and Verruciform Lichen Simplex Chronicus to Differentiated Exophytic Vulvar Intraepithelial Lesion and Vulvar Aberrant Maturation, the latter term having been recently proposed by the International Society for the Study of Vulvovaginal Diseases. In line with the recognition of these lesions by the 2020 World Health Organization Classification of Tumours as a neoplastic precursor, we herein propose the term HPV-independent, p53-wild-type verruciform acanthotic Vulvar Intraepithelial Neoplasia (HPVi(p53wt) vaVIN), which better conveys not only the pathology but also the neoplastic nature and the biologic risk inherent to these uncommon and challenging lesions. We outline strict morphologic and immunohistochemical criteria for its diagnosis and distinction from mimickers. Immunohistochemistry for p16 and p53 should be performed routinely in the diagnostic work-up of these lesions, and the morphologic alternative term vaVIN should be reserved for instances in which p16/HPV/p53 status is unknown. We also discuss management considerations and the need to further explore precursors within and beyond the spectrum of verruciform acanthotic vulvar intraepithelial neoplasia.

Molecular landscape of vulvovaginal squamous cell carcinoma: new insights into molecular mechanisms of HPV-associated and HPV-independent squamous cell carcinoma

Squamous cell carcinomas of the lower female genital tract may be human papillomavirus-associated or independent. We studied the HPV status, mutational repertoire, histology, and clinical data of 28 samples from 26 patients, 65% with a vulvar primary and 35% with a vaginal primary. These represented invasive vulvovaginal squamous cell carcinomas that underwent clinical tumor-normal targeted massively parallel sequencing analysis. HPV status was determined using the HPV high-risk RNA ISH assay and/or by MSK-IMPACT. Eleven patients had HPV-associated squamous cell carcinoma (four vulvar and seven vaginal) and 15 patients had HPV-independent SqCC (13 vulvar and 2 vaginal). Well-differentiated squamous cell carcinomas were always HPV-independent. HPV-independent moderately and poorly differentiated carcinomas frequently had alterations in the NOTCH signaling pathway (6/7), which were also associated with increased tumor budding (P: 0.002). HPV-associated vulvovaginal squamous cell carcinoma had PIK3CA activating mutations (7/11, 64%) as the most common genomic event, while TERT gene alterations, mainly TERT promoter mutations (14/15 cases, 93%) featured significantly in HPV-independent carcinomas. Other common abnormalities in HPV-independent tumors were TP53 mutations (13/15, 87%), CDKN2A alterations (10/15, 67%), and NOTCH1 and FAT1 mutations (7/15, 47% each). A subset of both HPV-associated and -independent tumors had NOTCH pathway alterations (6/11, 55% and 10/15, 67% respectively), but different genes in this pathway were altered in these tumors. In summary, TERT, TP53, CDKN2A, and NOTCH1 gene alterations strongly point away from an HPV-driven process (odds ratios: 0.01, 0.07, 0, and 0, respectively with p values < 0.02 for all four genes), while PIK3CA activating mutations without the other mutations strongly favors an HPV-driven tumor (odds ratio: 10.12, p value: 0.016). HPV-independent carcinomas are more likely to be moderately-poorly differentiated with intermediate to high tumor cell budding. Cancer cell fraction analysis of HPV-independent squamous carcinomas suggests that TERT and/or NOTCH1 alterations along with TP53 alterations can be the initiating event in these tumors.

Expression of B7 family checkpoint proteins in cervical cancer

The role of programmed cell death-ligand 1 (PD-L1) in cervical cancer has been widely investigated; however, the influences of other inhibitory B7 family members are poorly understood. We investigated the expression of PD-L1, B7 homolog 3 (B7-H3), B7-H4, and V-domain Ig suppressor of T-cell activation (VISTA) and their association with the clinicopathological features and outcomes of a large cohort of 673 patients with squamous cell carcinoma or adenocarcinoma of the uterine cervix. The positivity rates for PD-L1 (combined positive score ≥1), B7-H3 in tumor cells (TCs), B7-H4 (exclusively in TCs), VISTA in immune cells (ICs), and VISTA in TCs were 57.9%, 62.8%, 44.8%, 92.6%, and 4.8%, respectively, in 606 primary cervical cancer samples. Co-expression of PD-L1 with B7-H3 in TCs and with B7-H4 and VISTA in ICs was observed in 38.8%, 25.4%, and 57.9% of samples, respectively. B7-H3 in TCs and B7-H4 and VISTA in ICs were observed in 58.1%, 46.6%, and 83.1% of PD-L1-negative samples, respectively. These proteins were observed more frequently in squamous cell carcinomas and in moderately to poorly differentiated carcinomas. VISTA (in ICs) and B7-H4 were more frequent in primary tumors than in recurrent counterparts and correlated with improved survival; in contrast, B7-H3 positivity in TCs was less frequent in primary tumors and correlated with short disease-specific survival. Co-expression of B7-H4 and VISTA in ICs was an independent predictor of favorable outcomes overall and among patients with PD-L1-negative tumors. These data indicate that B7 family proteins exhibit differing expression patterns, distributions, and prognostic implications in cervical cancer. Furthermore, the co-expression of PD-L1 with other checkpoint proteins suggests that PD-1/PD-L1 blockade combined with modulating other immune checkpoints may present a novel therapeutic approach for cervical cancer. Future studies are needed to validate prognostic values of B7 family proteins and explore their biological roles in this malignancy.

Molecular characterization of invasive and in situ squamous neoplasia of the vulva and implications for morphologic diagnosis and outcome

Human papillomavirus (HPV)-independent vulvar squamous cell carcinoma (VSCC) is an aggressive clinical entity. Current diagnostic guidelines for premalignant lesions are ambiguous, and their molecular profile and progression events are still unclear. We selected 75 samples, from 40 patients, including 33 VSCC, 8 verrucous carcinomas (VC), 13 differentiated-type vulvar intraepithelial neoplasia (dVIN), 11 suspicious for dVIN (?dVIN), 6 differentiated exophytic vulvar intraepithelial lesions (DE-VIL), 2 vulvar acanthosis with altered differentiation (VAAD), and 2 usual-type vulvar intraepithelial neoplasia (uVIN/HSIL). Invasive and precursor lesions were matched in 29 cases. Clinical information, p16 immunohistochemistry, and mutation analysis were performed on all lesions. All dVIN, ?dVIN, DE-VIL, and VAAD were p16 negative, all uVIN/HSIL were p16 positive. In the HPV-independent group, mutations were identified in 6 genes: TP53 (n = 40), PIK3CA (n = 20), HRAS (n = 12), MET (n = 5), PTEN (n = 4), and BRAF (n = 1). TP53 mutations occurred in 73% (22/30) VSCC, 85% (11/13) dVIN, 70% (7/10) ?dVIN and no VC (0/8), DE-VIL (0/6) nor VAAD (0/2). Basal atypia was the only reliable feature of TP53 mutations. ?dVIN lesions that were non-acanthotic and atypical but obscured by inflammation, all harbored TP53 mutations. In lesions without TP53 mutations, PIK3CA (50% VC, 33% DE-VIL, 100% VAAD, 40% VSCC) and HRAS (63% VC, 33% DE-VIL, 0% VAAD, 20% VSCC) mutations were found. Mutational progression from in situ to invasive was seen (7/26, 27%) and usually involved TP53 (4/26, 15%). Cases with TP53 and PIK3CA co-mutations had the worse clinical outcomes (p < 0.001). We recommend testing for p53 in all HPV-independent lesions suspicious for dVIN, even in the presence of marked inflammation or non-acanthotic skin, particularly when close to a margin. VC, VAAD, and DE-VIL, were almost never mutated for TP53, but instead often harbored PIK3CA and HRAS mutations. In VSCC, combined TP53 and PIK3CA mutations may inform prognosis.

Differentiated exophytic vulvar intraepithelial lesion: Clinicopathologic and molecular analysis documenting its relationship with verrucous carcinoma of the vulva

Verruciform proliferations of the vulva unrelated to HPV infection are rare. The term differentiated exophytic vulvar intraepithelial lesion (DEVIL) was recently proposed for these lesions, which harbor recurrent PIK3CA mutations. It is still unclear whether DEVIL is related to verrucous carcinoma, a neoplasm characterized by persistence and local recurrence but nil risk of distant spread. Specimens identified using the words "verruciform" and "verrucous" were reviewed. Diagnosis of DEVIL required verruciform acanthosis, hyper and/or parakeratosis, hypogranulosis, cytoplasmic pallor, and bland nuclei. Verrucous carcinoma required, in addition, discontinuous, bulbous, puzzle-like nests in the stroma. A targeted next-generation sequencing using a custom 11-gene panel was performed. Eighteen specimens corresponding to ten patients with DEVIL and/or verrucous carcinoma were included. Median age at presentation was 66 years for DEVIL and 70 years for verrucous carcinoma. A similar spectrum of prevalent mutations was found in both lesions involving HRAS, PIK3CA, and BRAF. DEVIL preceded verrucous carcinoma and/or was diagnosed concurrently or in subsequent follow-up in five patients. In four of these, the same mutation was identified in DEVIL and synchronous or metachronous carcinoma. All cases showed wild-type 53 staining and lacked pathogenic TP53 mutations. DEVIL is a rare form of squamous proliferation characterized by prevalent PIK3CA and HRAS mutations. Its temporal relationship with verrucous carcinoma and their shared mutational profile in some patients suggest that DEVIL is a precursor of verrucous carcinoma. Moreover, given their morphologic and molecular overlap and the nil risk of verrucous carcinoma for distant spread, it is conceivable that DEVIL and verrucous carcinoma represent a spectrum of the same entity.

Major p53 immunohistochemical patterns in in situ and invasive squamous cell carcinomas of the vulva and correlation with TP53 mutation status

The recent literature has shown that vulvar squamous cell carcinoma (VSCC) can be stratified into two prognostically relevant groups based on human papillomavirus (HPV) status. The prognostic value of p53 for further sub-stratification, particularly in the HPV-independent group, has not been agreed upon. This disagreement is likely due to tremendous variations in p53 immunohistochemical (IHC) interpretation. To address this problem, we sought to compare p53 IHC patterns with TP53 mutation status. We studied 61 VSCC (48 conventional VSCC, 2 VSCC with sarcomatoid features, and 11 verrucous carcinomas) and 42 in situ lesions (30 differentiated vulvar intraepithelial neoplasia [dVIN], 9 differentiated exophytic vulvar intraepithelial lesions [deVIL], and 3 high-grade squamous intraepithelial lesions or usual vulvar intraepithelial neoplasia [HSIL/uVIN]). IHC for p16 and p53, and sequencing of TP53 exons 4-9 were performed. HPV in situ hybridization (ISH) was performed in selected cases. We identified six major p53 IHC patterns, two wild-type patterns: (1) scattered, (2) mid-epithelial expression (with basal sparing), and four mutant patterns: (3) basal overexpression, (4) parabasal/diffuse overexpression, (5) absent, and (6) cytoplasmic expression. These IHC patterns were consistent with TP53 mutation status in 58/61 (95%) VSCC and 39/42 (93%) in situ lesions. Cases that exhibited strong scattered staining and those with a weak basal overexpression pattern could be easily confused. The mid-epithelial pattern was exclusively observed in p16-positive lesions; the basal and parabasal layers that had absent p53 staining, appeared to correlate with the cells that were positive for HPV-ISH. This study describes a pattern-based p53 IHC interpretation framework, which can be utilized as a surrogate marker for TP53 mutational status in both VSCC and vulvar in situ lesions.

Grading of endocervical adenocarcinoma: a novel prognostic system based on tumor budding and cell cluster size

A novel 3-tiered grading system based on tumor budding activity and cell nest size has been validated to be highly prognostic in organ-wide squamous cell carcinomas. In this study, we applied a similar grading system with slight modification to assess the prognostic value in an institutional cohort of well annotated endocervical adenocarcinomas (EAC) consisting of 398 consecutive cases with surgical resection, no neoadjuvant chemotherapy, and higher than stage pT1a. Each case was reviewed by the International Endocervical Adenocarcinoma Criteria and Classification (IECC) and Silva pattern classification, and scored on tumor budding activity and cell cluster size to form the basis of a novel grading system. High budding activity, small tumor cell cluster size, and novel grade 3 were more frequently associated with a decreased overall survival time and tumor recurrence time (p  0.05). In conclusion, our study demonstrates that the grading system based on tumor budding activity and cell cluster size is robust in prognostic assessment that outperforms the conventional FIGO grading and Silva pattern classification in EAC. The novel grading system, if further validated, could be applicable in routine pathologic descriptions of EAC by providing useful information in clinical decision-making.

Ovarian Sex Cord Tumor With Annular Tubules (SCTAT) Harbor Recurrent Copy Number Alterations, Including Monosomy 22

Sex cord tumor with annular tubules (SCTAT) is a rare ovarian sex cord-stromal neoplasm of low or intermediate malignant potential. Although some SCTATs are associated with Peutz-Jeghers syndrome (PJS), the majority arise in the nonsyndromic setting and typically lack STK11 mutations. As molecular alterations other than STK11 in SCTAT are largely unknown, we sought characterize the genomic landscape in these neoplasms better. SCTATs (n = 22) from 20 patients (5 with PJS, 1 with Prader-Willi syndrome, and 14 with no known syndromic status) were retrospectively identified. STK11 (LKB1) immunohistochemistry (IHC) was performed. Panel-based DNA sequencing was used to detect copy number variations and point mutations in 447 genes in 12 tumors from patients with no history of PJS, with 1 additional non-PJS tumor undergoing only targeted STK11 sequencing. Molecular profiles were compared with other ovarian sex cord-stromal tumors (n = 67). An STK11 mutation and concurrent loss of heterozygosity was in 1 of 13 sporadic tumors. STK11 IHC was intact (n = 14) or equivocal (n = 2) for STK11 wild-type tumors and lost in 1 sporadic tumor with STK11 mutation and 5 tumors from patients with known PJS. TERT promoter mutations were present in 6 of 12 tumors. Recurrent copy number alterations included monosomy 22 (8/12), as well as low-level copy number gains of FOXL2 (10/12; median, 4.3 estimated copies in FOXL2-gained tumors; range, 2.6-7.9), WT1 (9/12), and GATA4 (8/12). One tumor demonstrated biallelic inactivation of TP53 in a region of high-grade transformation characterized by significant cytologic atypia, mitotic activity, and necrosis. In conclusion, nonsyndromic SCTATs are molecularly characterized by FOXL2, WT1, and GATA4 gains, monosomy 22, and TERT promoter mutations. High-grade transformation may rarely occur, a phenomenon not previously described, and is associated with TP53 mutation. STK11 IHC appears to be a reliable surrogate for STK11 mutations and may be useful in suggesting a PJS-related tumor.

GLI1-Altered Tumors of the Ovary: A Report of 4 Cases of an Underrecognized Neoplasm That May Mimic Sex Cord–Stromal Tumors

GLI1 (glioma-associated oncogene homologue 1) altered neoplasms are an emerging group of tumors of presumed mesenchymal derivation, which occur mostly in the head and neck or soft tissues of the trunk and extremities. We have recently identified 4 ovarian neoplasms with GLI1 gene fusions; all were initially diagnosed as unusual sex cord-stromal tumors (n = 3) or endometrioid adenocarcinoma with sex cord-like morphology (n = 1). Patients' age ranged from 11 to 70 years and tumor size from 3 to 15 cm; all were confined to the ovary. Three tumors displayed dominant patterns of large irregular aggregates and smaller well-delineated nests of round cells with minimal to moderate amounts of clear to eosinophilic cytoplasm and monotonous round to ovoid nuclei divided by collagenous septae and focal myxoid areas. The final tumor showed alternating hypocellular and cellular areas composed of a loose, haphazard arrangement of spindled cells associated with myxoid stroma, imparting a "lace-like" reticular appearance, with only focal nested round cell morphology (20%). Additional minor patterns included tubules (n = 3), trabeculae (n = 2), follicle-like macrocysts (n = 2), cords (n = 1), microcysts (n = 1), and rosette-like formations (n = 1). Mitotic activity was minimal (<1 to 2/10 high-power fields). All tumors had a network of numerous capillary-sized vessels. Two tumors had some positivity for markers of sex cord-stromal differentiation, with focal, strong calretinin expression in one and diffuse, weak SF1 in another. RNA-based next-generation sequencing revealed PTCH1::GLI1 fusions in all 3 tumors with round cells and an ACTB::GLI1 fusion in the predominantly spindled tumor. Our experience with these tumors, particularly the discovery of 3 of the cases in a relatively short time frame, suggests that they are underrecognized in the ovary, where their morphologic features often mimic those of sex cord-stromal neoplasms. Awareness of their morphologic features and appropriate use of genetic testing will ensure accurate diagnosis and lead to a greater understanding of these rare neoplasms.

Comprehensive Molecular, Pathological, and Clinical Characterization of Clear Cell Adenocarcinoma of the Urinary Tract

Unraveling the Molecular Landscape of Uterine Tumor Resembling Ovarian Sex Cord Tumor: Insights From A Clinicopathological, Morphologic, Immunohistochemical, and Molecular Analysis of 35 Cases

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor of uncertain lineage and low malignant potential. Most tumors behave in a benign manner, but a subset of UTROSCT exhibit an aggressive clinical course with recurrences and metastases. The recurrent molecular alterations in UTROSCT mostly represent gene fusions involving NCOA1-3. We performed a comprehensive clinicopathological, morphologic, immunohistochemical, and molecular analysis on a cohort of 35 UTROSCT. The tumors exhibited various architectural patterns (diffuse, corded/trabecular, tubular, sertoliform, fascicular, whorled, nested, microfollicular, and pseudoglandular), often in combination. The immunohistochemical analysis confirmed the polyphenotypic immunoprofile, often with coexpression of sex cord-stromal, smooth muscle, and epithelial markers, as well as hormone receptors. Next-generation sequencing RNA analysis revealed recurrent NCOA1-3 gene fusions in 22/32 analyzed cases (69%), including ESR1::NCOA3 (11/22), GREB1::NCOA2 (7/22), ESR1::NCOA2 (3/22), and GREB1::NCOA1 (1/22). Tumor mutation burden was low in all cases. The fusion-positive cases exhibited statistically significant association with whorled architecture, conversely necrosis was associated with fusion-negative status. We did not find a significant relationship between any architectural pattern and GREB1 alterations, but the NCOA2-altered tumors were associated with pseudoglandular architecture. The GREB1-altered cases occurred in older patients and tended to be more often intramural masses compared with ESR1-altered cases. On the contrary, the ESR1-altered cases presented more often like submucosal or polypoid tumors. Two tumors exhibited aggressive behavior with recurrent disease. Both of these cases harbored a GREB1::NCOA2 fusion. Unsupervised hierarchical cluster analysis of our cohort revealed 2 main clusters. The tumors with GREB1 or NCOA2 fusion cluster together, suggesting that there are underlying molecular differences between these cases and cases with ESR1::NCOA3 fusion or without fusion. Our findings contribute to the growing knowledge about a rare neoplasm with currently uncertain biological behavior.

Dedifferentiated and Undifferentiated Ovarian Carcinoma: An Aggressive and Molecularly Distinct Ovarian Tumor Characterized by Frequent SWI/SNF Complex Inactivation

Dedifferentiated and undifferentiated ovarian carcinomas (DDOC/UDOC) are rare neoplasms defined by the presence of an undifferentiated carcinoma. In this study, we detailed the clinical, pathological, immunohistochemical, and molecular features of a series of DDOC/UDOC. We collected a multi-institutional cohort of 23 DDOC/UDOC and performed immunohistochemistry for core switch/sucrose nonfermentable (SWI/SNF) complex proteins (ARID1A, ARID1B, SMARCA4, and SMARCB1), mismatch repair (MMR) proteins, and p53. Array-based genome-wide DNA methylation and copy number variation analyses were performed on a subset of cases with comparison made to a previously reported cohort of undifferentiated endometrial carcinoma (UDEC), small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), and tubo-ovarian high-grade serous carcinoma (HGSC). The age of all 23 patients with DDOC/UDOC ranged between 22 and 71 years (with an average age of 50 years), and a majority of them presented with extraovarian disease (16/23). Clinical follow-up was available for 19 patients. Except for 2 patients, the remaining 17 patients died from disease, with rapid disease progression resulting in mortality within a year in stage II-IV settings (median disease-specific survival of 3 months). Eighteen of 22 cases with interpretable immunohistochemistry results showed loss of expression of core SWI/SNF protein(s) that are expected to result in SWI/SNF complex inactivation as 10 exhibited coloss of ARID1A and ARID1B, 7 loss of SMARCA4, and 1 loss of SMARCB1. Six of 23 cases were MMR-deficient. Two of 20 cases exhibited mutation-type p53 immunoreactivity. Methylation profiles showed coclustering of DDOC/UDOC with UDEC, which collectively were distinct from SCCOHT and HGSC. However, DDOC/UDOC showed an intermediate degree of copy number variation, which was slightly greater, compared with SCCOHT but much less compared with HGSC. Overall, DDOC/UDOC, like its endometrial counterpart, is highly aggressive and is characterized by frequent inactivation of core SWI/SNF complex proteins and MMR deficiency. Its molecular profile overlaps with UDEC while being distinct from SCCOHT and HGSC.

Systematic Analysis of Homologous Recombination Deficiency Testing in Ovarian Cancer—Development of Recommendations for Optimal Assay Performance

Homologous recombination deficiency (HRD) assays are an important element of personalized oncology in ovarian carcinomas, but the optimal tissue requirements for these complex molecular assays remain unclear. As a result, a considerable percentage of assays are not successful, leading to suboptimal diagnoses for these patients. In this study, we have systematically analyzed tumor and tissue parameters for HRD analysis in a large cohort of real-world cancer samples. The aim of this study is to give recommendations for pathologists and gynecologic oncologists for selection of tissue samples to maximize the success rate of HRD analyses. Tumor samples from 2702 patients were sent to the Institute of Pathology of the Philipps-University Marburg between October 2020 and September 2022, of which 2654 were analyzed using the Myriad MyChoice HRD+ CDx assay. A total of 2396 of 2654 samples (90.3%) were successfully tested, of which 984 of 2396 (41.1%) were HRD positive and 1412 (58.9%) were HRD negative. Three hundred sixty-three of 2396 samples (15.2%) were BRCA1/2-mutated; 27 samples had a BRCA1/2 mutation and a genomic instability score (GIS) < 42. Twenty-two samples (0.9%) failed GIS measurement but displayed a BRCA1/2 mutation. BRCA1/2-mutated samples showed significantly (P < .0001) higher GIS values than those with a wild-type BRCA1/2 status. Tumor cell content, tumor area, and histology significantly (P < .0001) affected the probability of successfully analyzing a sample. Based on a systematic analysis of tumor cell content and tumor area, we recommend selecting patient high-grade serous ovarian cancer samples that display a tumor cell content ≥30% and a tumor area ≥0.5 cm

Expression and Prognostic Significance of LAG-3, TIGIT, VISTA, and IDO1 in Endometrial Serous Carcinoma

Endometrial serous carcinoma (ESC) is an uncommon, aggressive type of endometrial cancer. While immune checkpoint blockade has emerged as a promising treatment option for endometrial carcinomas, research on the expression of immune checkpoints that could serve as prospective immunotherapy targets in ESC is limited. We examined the prevalence and prognostic value of lymphocyte-activation gene 3 (LAG-3), T-cell immunoglobulin and ITIM domain (TIGIT), V-domain immunoglobulin (Ig) suppressor of T-cell activation (VISTA), and indoleamine 2,3-dioxygenase 1 (IOD1) in 94 cases of ESC and correlated their expression with CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs). We observed a positive correlation among LAG-3, TIGIT, and VISTA expressed on immune cells, and among these markers and CD8+ and FOXP3+ TIL densities. In Kaplan-Meier survival analysis, tumors with high levels of LAG-3 and TIGIT expression had better progression-free survival (PFS) and overall survival (OS) than those with lower levels of expression (LAG-3: PFS, P = .03, OS, P = .04; TIGIT: PFS, P = .01, OS, P = .009). In multivariate analysis, only high TIGIT expression was of independent prognostic value for better OS. VISTA expression in immune or tumor cells, and IDO1 expression in tumor cells, did not show a significant association with survival. Our data indicate that LAG-3, TIGIT, and VISTA immune checkpoints have roles in the microenvironment of ESC, and their expression patterns highlight the complex interactions among the different components of this system. High levels of these markers, together with high CD8+ TIL, suggest the potential immunogenicity of a subset of these tumors. Further studies are needed to elucidate the roles of various immune components in the ESC microenvironment and their association with intrinsic tumor properties.

Variability in endometrial carcinoma pathology practice: opportunities for improvement with molecular classification

We assessed the landscape of diagnostic pathology practice and how molecular classification could potentially impact management of patients with endometrial cancer by collecting patient samples, clinicopathologic data, and patient outcomes from EC patients diagnosed in 2016 at 10 Canadian tertiary cancer centers and 19 community hospitals. ProMisE molecular subtype (POLEmut, MMRd, p53abn, No Specific Molecular Profile (NSMP)) was assigned retrospectively. 1357 patients were fully evaluable including 85 POLEmut (6.3%), 380 MMRd (28.0%), 643 NSMP (47.4%), and 249 p53abn ECs (18.3%). Immunohistochemistry (IHC) for MMR proteins was undertaken at the time of primary diagnosis in 2016 in only 42% of the cohort (570/1357; range 3.5-95.4%/center). p53 IHC had only been performed in 21.1% of the cohort (286/1357; range 10.1-41.9%/center). Thus, based on the retrospective molecular subtype assignment, 54.7% (208/380) of MMRd EC had not been tested with MMR IHC (or MSI) and 48.2% (120/249) of p53abn ECs were not tested with p53 IHC in 2016. Molecular subtype diversity within histotypes was profound; most serous carcinomas were p53abn (91.4%), but only 129/249 (51.8%) p53abn EC were serous. Low-grade (Gr1-2) endometrioid carcinomas were mostly NSMP (589/954, 61.7%) but included all molecular subtypes, including p53abn (19/954, 2.0%). Molecular subtype was significantly associated with clinical outcomes (p < 0.001) even in patients with stage I disease (OS p = 0.006, DSS p < 0.001, PFS p < 0.001). Assessment of national pathologic practice in 2016 shows highly variable use of MMR and p53 IHC and demonstrates significant opportunities to improve and standardize biomarker reporting. Inconsistent, non-reflexive IHC resulted in missed opportunities for Hereditary Cancer Program referral and Lynch Syndrome diagnosis, and missed potential therapeutic implications (e.g., chemotherapy in p53abn EC, immune blockade for MMRd EC). Routine integration of molecular subtyping into practice can improve the consistency of EC pathology assessment and classification.

A Subset of Serous Tubal Intraepithelial Carcinoma (STIC)–Like Lesions and Concurrent High-Grade Endometrial Carcinoma Are Genomically Related Entities

In patients with high-grade endometrial carcinoma (HG-EC), concurrent isolated serous tubal intraepithelial carcinoma (STIC) or STIC-like lesions (STIC-LLs) in the fallopian tube(s) may be found. We sought to determine whether concurrently diagnosed HG-ECs and STIC-LLs are genetically related. Six HG-ECs, including serous carcinomas (n = 4) and carcinosarcomas with serous epithelial component (n = 2), with cooccurring STIC-LLs were identified and subjected to microdissection, DNA extraction, and panel sequencing targeting 468 cancer-related genes or, if DNA quantities were limited, to Sanger sequencing. WT1 and p53 protein expression was assessed by immunohistochemistry. We found that 3 HG-ECs and concurrent STIC-LLs shared pathogenic mutations, such as TP53 hotspot, NF2, FBXW7, and PIK3CA mutations. Immunohistochemical analysis revealed that the HG-EC of case 5 lacked WT1 expression and had aberrant p53 expression, although the matched STIC-LL displayed diffuse WT1 expression. Of the remaining 3 cases that did not show evidence of genetic relatedness based on the targeted sequencing panel, 1 STIC-LL harbored a clonal TP53 missense mutation, whereas the matched HG-EC had a distinct clonal TP53 hotspot mutation, a clonal FBXW7 hotspot mutation, and ERBB2 amplification. At the protein level, the p53 expression patterns of the HG-ECs and STIC-LLs were concordant in these 3 cases. Here, we demonstrate that cooccurring HG-ECs and STIC-LLs are genetically related in a subset of cases.

Lymphovascular Space Invasion in Endometrial Cancer: Does it Matter Where and How Much to Sample? A Macroscopic Study of 208 Hysterectomies

Lymphovascular space invasion (LVSI) is a key prognostic factor in endometrial cancer, guiding adjuvant treatment decisions. This retrospective study analyzed 208 hysterectomy specimens with confirmed LVSI to determine optimal sampling strategies for detecting substantial LVSI. Samples/blocks from tumor infiltration fronts were reviewed microscopically, and LVSI foci were counted per slide and summed across all slides. Cutoffs of ≥5, ≥4, and ≥3 LVSI foci were evaluated. Only the ≥5 threshold significantly correlated with lymph node metastasis (P = .038) compared with <5 LVSI. Both patients with ≥5 LVSI foci either on a single slide or those reaching this threshold by summing across slides were associated with nodal metastasis (P = .023). However, significantly worse overall survival was observed only in patients with ≥5 foci on a single slide, not in those reaching the threshold by summing across multiple slides (P < .001). Focal LVSI (<5 foci) showed no significant overall survival compared with substantial LVSI. Increased sampling from the tumor infiltration front improved LVSI detection rates (P < .001), but gains in detecting substantial LVSI plateaued after 7 samples/blocks. Higher LVSI levels were associated with deep LVSI and cervical/endocervical LVSI (P < .001). Deep LVSI was linked to reduced overall survival compared with superficial LVSI (P < .001), whereas cervical/endocervical LVSI showed no significant association with overall survival (P = .273). Tumor grade, deep LVSI, and cervical involvement predicted nodal metastasis, whereas the microcystic, elongated, and fragmented pattern did not. These findings support using a threshold of ≥5 LVSI foci on at least 1 slide-as opposed to summing across slides-as a marker of worse overall survival. For optimal evaluation, at least 7 tumor infiltration front samples/blocks should be taken, including deep myometrium and cervical/endocervical canal, to ensure adequate assessment and identify patients at higher risk of nodal spread.

Uterine Sarcomas With Recurrent KDM2B Gene Fusions: Three Cases of a Possible Novel Subtype of High-Grade Endometrial Stromal Sarcoma

The advent of widespread genomic testing of uterine mesenchymal tumors has led to novel insights into the biology of these diverse tumors, and many genomically defined entities have been described in recent years. During a larger study of endometrial stromal sarcomas and unclassified uterine sarcomas, we identified 3 tumors harboring KDM2B gene fusions. Patients were 32, 61, and 67 years old, and all initially underwent incomplete sampling via laparoscopic myomectomy (n = 1), laparoscopic biopsy (n = 1), or hysteroscopic myomectomy (n = 1). One patient's tumor was densely adherent to the pelvic sidewall; she was treated with chemotherapy and died of widely metastatic disease at 29 weeks. Another underwent a subsequent recent hysterectomy with the tumor confined to the uterus and minimal follow-up to date. The final patient refused further treatment and was alive at 28 weeks, although the status of the disease progression was unknown. On microscopic examination, 2 tumors showed infiltrative borders, whereas interface with the myometrium was not present in the third. The tumors were variably cellular with alternating hypercellular and hypocellular zones in a myxoid to loosely collagenous stroma. The hypercellular areas contained round to ovoid cells in diffuse (n = 3) and sex cord-like arrangements, including cords (n = 3), nests (n = 2), and tubules (n = 1); 2 also contained occasional spindled cells arranged in vague fascicles. These cells showed moderate atypia with open chromatin, numerous mitoses (8, 24, and 25 per 10 high-power fields), and frequent apoptosis. The hypocellular areas contained sparse, ovoid-to-spindled cells with minimal atypia. All tumors were diffusely positive for cyclin D1, whereas BCL6 corepressor was diffusely positive in 1 and negative in 2; desmin and caldesmon were negative in all 3 neoplasms. All harbored KDM2B gene fusions; partner genes included EPC1, EP400, and CITED1. MDM2 amplification was also noted in 2. Clustering analysis based on RNA expression profiling revealed tight clustering of all 3 tumors within the broad group of high-grade endometrial stromal sarcomas. Based on the overall clinicopathologic and genomic features, we suggest that these tumors may represent a novel subtype of uterine sarcoma and may be best classified as high-grade endometrial stromal sarcoma, although additional confirmatory studies are needed.

Endometrial Carcinomas With a Somatically Derived Yolk Sac Tumor Component Share Molecular Similarities to p53–abnormal Endometrial Carcinomas and Germ Cell Tumors

Primary endometrial carcinomas with somatically derived yolk sac tumor (YST) components are rare. We analyzed 23 such cases using detailed clinicopathologic, immunohistochemical, and molecular methods. The median patient age was 68 years. Elevated serum alpha-fetoprotein (AFP) was detected in 76.9% (10/13) of tested cases. International Federation of Gynecology and Obstetrics (FIGO) 2009 stages were I (n = 12, 55%), II (n = 1, 5%), III (n = 5, 23%), IV (n = 4, 18%), and unknown in one. Histologic YST patterns included glandular (87%), papillary (52%), solid (48%), endodermal sinus (17%), hepatoid (17%), and reticular (13%) architectures. The associated Müllerian-type neoplasms were endometrioid carcinoma (n = 17), carcinosarcoma (n = 3), serous carcinoma (n = 2), and clear cell carcinoma (n = 1). Immunohistochemically, 17 cases (74%) exhibited mutation-type p53 staining, and 2 (9%) were mismatch repair-deficient (MMRd). YST components uniformly expressed glypican-3 and spalt-like transcription factor 4 (SALL4), whereas 17 (74%) also expressed AFP. HER2 positivity was seen in 13 of 21 tested (62%; four 3+, three 2+, and six 1+). Molecular analysis revealed TP53 variants in 16 of 22 cases (73%) without POLE hotspot mutations. According to The Cancer Genome Atlas molecular classification, 17 tumors were p53-abnormal (74%), 2 (9%) MMRd, 4 (17%) were no specific molecular profile, and none was POLE-ultramutated. Recurrent copy number gains involved CCNE1 (9/22, 41%), 1q44 (12/14, 86%), and 3q26.32 (8/14, 57%). Features reminiscent of germ cell tumors included amplifications at 7p21.2 (8/14, 57%) and 9p21.3 (11/14, 79%), polysomy or amplification of chromosome 12p (6/22, 27%), deletion at 11q24.3 (8/14, 57%), and a high frequency of T>C nucleotide substitutions. Follow-up showed 15 patients (75%) had died of disease or were alive with disease; 12 of these 15 cases were p53-abnormal. Overall survival was significantly poorer than in other molecular subtypes of endometrial carcinoma. These tumors should therefore be regarded as high grade (grade 3) by definition. In summary, endometrial carcinomas with a somatically derived YST component are highly aggressive, predominantly p53-abnormal, with smaller subsets classified as MMRd or no specific molecular profile. Recognition of the YST component is crucial, and biomarker profiling may reveal therapeutic targets.

Spatial Cancer-Immune Phenotypes Predict Shorter Recurrence-Free Survival in the No Specific Molecular Profile Molecular Subtype of Endometrial Carcinoma

Compartmentation of the immune response into 3 main spatial cancer-immune phenotypes (SCIs) - inflamed, excluded, and desert - has been proposed as the main predictor of response to immune checkpoint inhibitors in solid tumors. The objective of the study was to define and characterize the SCI in a consecutive series of 213 endometrial carcinomas (ECs) by correlating it with molecular subtypes, clinicopathologic features, and prognosis. Immunohistochemistry (IHC) and next-generation sequencing were used to assign surrogate molecular EC subtypes: POLE mutant (POLE), mismatch repair deficient (MMRd), TP53 mutant (p53abn), and no specific molecular profile (NSMP). Immune cell markers (CD20, CD3, CD8, CD68, PD-L1) were assessed by IHC on whole sections and quantified by digital image analysis to define the 3 SCIs. ECs were stratified into 4 molecular subtypes: 17 (8.0%) POLE, 68 (31.9%) MMRd, 42 (19.7%) p53abn, and 86 (40.4%) NSMP. SCI determination showed 105 (49.3%) inflamed, 62 (29.1%) desert, and 46 (25.6%) excluded tumors. The inflamed phenotype was more prevalent in MMRd (64.7%) and POLE (76.5%) subtypes compared with NSMP (45.3%) and p53abn (21.4%). SCI revealed a strong correlation with disease-free survival in NSMP tumors: inflamed 96.2%, desert 83.2%, and excluded 40.5%. The SCI prognostic impact was also maintained in NSMP cases treated with adjuvant therapy resulting in a significant difference in recurrence between the inflamed and excluded phenotypes. To simplify SCI determination, a subset of immune cell markers was selected as appropriate to define the 3 SCI patterns: high intraepithelial CD8 for the inflamed phenotype; CD68, CD20, and PD-L1 to discriminate between desert and excluded tumors. The integration of SCI into molecular classification could be a promising opportunity to improve the prognostic risk stratification of patients and may guide the therapeutic approach, particularly in the NSMP subtype. Thus, the different patterns of immune response are a new prognostic parameter in the NSMP subtype.

HER2 Genetic Intratumor Heterogeneity Is Associated With Resistance to Trastuzumab and Trastuzumab Emtansine Therapy in Recurrent High-Grade Endometrial Cancer

Anti-HER2 targeted therapies have recently demonstrated clinical activity in the treatment of high-grade endometrial carcinomas (ECs), particularly serous carcinomas with HER2 amplification and/or overexpression. Intratumor heterogeneity of HER2 amplification or HER2 genetic intratumor heterogeneity (G-ITH) has been associated with resistance to anti-HER2 therapies in breast and gastroesophageal cancers; however, its clinical relevance in EC is unknown. To characterize HER2 G-ITH in EC, archival specimens from a clinically annotated cohort of 57 ECs treated with trastuzumab or trasutuzmab emtansine in the recurrent (n = 38) or adjuvant (n = 19) setting were subjected to central pathology review, HER2 assessment by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), and next-generation sequencing. HER2 G-ITH, defined as HER2 amplification in 5% to 50% of tumor cells examined by FISH, was identified in 36% (19/53) of ECs and was associated with lower HER2 copy number and levels of protein expression. HER2 IHC revealed spatially distinct areas of strong expression juxtaposed with areas of low/absent expression in tumors with the "cluster" pattern of G-ITH, whereas the "mosaic" pattern was typically associated with a diffuse admixture of cells with variable levels of HER2 expression. HER2 G-ITH was frequently observed in cases with IHC/FISH or FISH/next-generation sequencing discrepancies and/or with an equivocal/negative FISH result (9/13, 69%). Although the objective response rate to anti-HER2 therapy in recurrent ECs was 52% (13/25) for tumors lacking HER2 G-ITH, none (0%, 0/10) of the patients with HER2 G-ITH achieved a complete or partial response (P = .005). HER2 G-ITH was significantly associated with worse progression-free survival (hazard ratio, 2.88; 95% CI, 1.33-6.27; P = .005) but not overall survival. HER2 IHC score, HER2/CEP17 ratio, HER2 copy number, histologic subtype, and other genetic alterations, including PIK3CA hotspot mutations, were not significantly associated with therapeutic response or survival outcomes. Treatment responses were not restricted to serous carcinomas, supporting consideration of anti-HER2 therapy in patients with HER2-positive high-grade ECs of non-serous histology. Our results demonstrate that HER2 G-ITH is an important determinant of response to trastuzumab and trastuzumab emtansine in EC, providing a rationale for the development of novel therapeutic strategies to target HER2-nonamplified resistant tumor subpopulations, such as HER2 antibody-drug conjugates with bystander effects.

The KAT6B::KANSL1 Fusion Defines a New Uterine Sarcoma With Hybrid Endometrial Stromal Tumor and Smooth Muscle Tumor Features

Neoplasms harboring a KAT6B/A::KANSL1 fusion were initially reported as benign (leiomyomas) and malignant (leiomyosarcomas, low-grade endometrial stromal sarcomas [LG-ESSs]) uterine neoplasms. However, they may represent an emerging entity characterized by clinical aggressiveness contrasting with a rather reassuring microscopic appearance. Here, we aimed to confirm that this neoplasm is a distinct clinicopathologic and molecular sarcoma and identify criteria that should alert pathologists and lead to KAT6B/A::KANSL1 fusion testing in routine practice. Therefore, we conducted a comprehensive clinical, histopathologic, immunohistochemical, and molecular study, including array comparative genomic hybridization, whole RNA-sequencing, unsupervised clustering, and cDNA mutational profile analyses of 16 tumors with KAT6B::KANSL1 fusion from 12 patients. At presentation, patients were peri-menopausal (median, 47.5 years), and the primary tumors were located in the uterine corpus (12/12, 100%), with an additional prevesical location in 1 (8.3%) of 12 cases. The relapse rate was 33.3% (3/9). All tumors (16/16, 100%) showed morphologic and immunohistochemical features overlapping between leiomyoma and endometrial stromal tumors. A whirling recurrent architecture (resembling fibromyxoid-ESS/fibrosarcoma) was found in 13 (81.3%) of 16 tumors. All tumors (16/16, 100%) exhibited numerous arterioliform vessels, and 13 (81.3%) of 18 had large hyalinized central vessels and collagen deposits. Estrogen and progesterone receptors were expressed in 16 (100%) of 16 and 14 (87.5%) of 16 tumors, respectively. Array comparative genomic hybridization performed on 10 tumors classified these neoplasms as simple genomic sarcomas. Whole RNA-sequencing on 16 samples and clustering analysis on primary tumors found that the KAT6B::KANSL1 fusion always occurred between exons 3 of KAT6B and 11 of KANSL1; no pathogenic variant was identified on cDNA, all neoplasms clustered together, close to LG-ESS, and pathway enrichment analysis showed cell proliferation and immune infiltrate recruitment pathway involvement. These results confirm that the sarcomas harboring a KAT6B/A::KANSL1 fusion represent a distinct clinicopathologic entity, close to LG-ESS but different, with clinical aggressiveness despite a reassuring morphology, for which the KAT6B/A::KANSL1 fusion is the molecular driver alteration.

Loss of Ribosomal Protein L22 (RPL22) Expression Identifies a Transcriptional Subset of MLH1-Deficient Endometrial Cancers With Lower Numbers of Tumor-Associated Lymphocytes

Microsatellite instability-high defines one of the major subsets of endometrial cancer (EC), characterized by defects in DNA mismatch repair, most often by loss of MLH1 protein expression, and sensitivity to immunotherapies. RPL22 is selectively mutated in microsatellite instability-high cancers, resulting in loss of protein expression. The significance of this mutation is unknown. An immunohistochemistry assay was developed that reliably detected ECs with ribosomal protein L22 (RPL22) protein loss. With a cohort of ECs, we identified MLH1-deficient cancers with loss of RPL22 expression. Using digital spatial transcriptomics, a subset was identified that was characterized by no expression of RPL22, lower expression of β-2 microglobulin, lack of expression of immune activation pathways, and lower numbers of tumor-associated CD8+ lymphocytes. β-2 Microglobulin, which is necessary for antigen presentation to T lymphocytes, was decreased in EC cell lines with RPL22 knocked down. Neither RPL22 expression nor levels of tumor-associated T lymphocytes were associated with tumor mutation burden or PD-L1 expression, 2 biomarkers that are assessed in patients considered for immunotherapies. This study provides the first evidence that RPL22 deficiency is an easily measured indicator of a unique subset of MLH1-deficient ECs that can be characterized as immune low. Our study suggests that patients with RPL22-deficient tumors could represent poor candidates for CD8+ T-cell-based immunotherapies, a current frontline therapy for MLH1-deficient ECs.

Differential Localization of β-Catenin Protein in CTNNB1 Mutant Endometrial Cancers Results in Distinct Transcriptional Profiles

CTNNB1 exon 3 mutation is a well-established driver of nearly 30% of endometrioid endometrial cancers (EECs), and this is associated with worse patient survival. Paradoxically, we have previously demonstrated that mutant β-catenin protein does not robustly localize to the nucleus in these cancers. The purpose of this study was to determine downstream gene expression in these cancers with nuclear or membrane/cytoplasmic mutant β-catenin protein localization. Spatial transcriptomics was performed on tumors with intratumor nuclear and nonnuclear mutant β-catenin, using the protein localization to select for regions of interest (ROIs). Differential expression analysis of all nuclear and nonnuclear ROIs yielded distinct transcriptional profiles based on the localization of β-catenin. Analysis revealed enrichment for Wnt signaling and epithelial-to-mesenchymal transition pathways in nuclear ROIs and hormone signaling in nonnuclear ROIs. Hierarchical clustering yielded 2 clusters comprised of almost entirely nuclear or nonnuclear ROIs. A novel therapeutic target, TROP2, encoded by the TACSTD2 gene, was identified to be altered by Wnt/β-catenin signaling. These data provide evidence for highly heterogeneous intratumor transcriptional profiles dependent on β-catenin protein localization in EEC with CTNNB1 driver mutations. Therefore, reporting of β-catenin immunohistochemistry should include an estimated percentage of tumor with nuclear localization in EEC tumors with exon 3 CTNNB1 mutations.

DNA Methylation Signature of Synchronous Endometrioid Endometrial and Ovarian Carcinomas

Next-generation sequencing (NGS) studies have demonstrated that co-occurring sporadic endometrioid endometrial carcinoma (EEC) and endometrioid ovarian carcinoma (EOC) are clonally related, suggesting that they originate from a single primary tumor. Despite clonality, synchronous EEC and EOC when diagnosed at early stage behave indolently, similar to isolated primary EEC or isolated primary EOC. In the present study, we compared the DNA methylation signatures of co-occurring EEC and EOC with those of isolated primary EEC and isolated primary EOC. We also performed targeted NGS to assess the clonal relatedness of 7 co-occurring EEC and EOC (4 synchronous EEC and EOC and 3 metastatic EEC based on pathologic criteria). NGS confirmed a clonal relationship in all co-occurring EEC and EOC. DNA methylation profiling showed distinct epigenetic signatures of isolated primary EEC and isolated primary EOC. Endometrial tumors from co-occurring EEC and EOC clustered with isolated primary EEC while their ovarian counterparts clustered with isolated primary EOC. Three co-occurring EEC and EOC cases with peritoneal lesions showed a closer epigenetic signature and copy number variation profile between the peritoneal lesion and EOC than EEC. In conclusion, synchronous sporadic EEC and EOC are clonally related but demonstrate a shift in DNA methylation signatures between ovarian and endometrial tumors as well as epigenetic overlap between ovarian and peritoneal tumors. Our results suggest that tumor microenvironment in the ovary may play a role in epigenetic modulation of metastatic EEC.

The Significance of International Federation of Gynecology and Obstetrics Grading in Microsatellite Instability-High and POLE-Mutant Endometrioid Endometrial Carcinoma

With the advancement of diagnostic molecular technology and the molecular classification of endometrial endometrioid carcinoma (EEC), it remains to be seen whether conventional International Federation of Gynecology and Obstetrics (FIGO) grading retains clinical significance in certain molecular subtypes of EECs. In this study, we explored the clinical significance of FIGO grading in microsatellite instability-high (MSI-H) and POLE-mutant EECs. A total of 162 cases of MSI-H EECs and 50 cases of POLE-mutant EECs were included in the analysis. Significant differences in tumor mutation burden (TMB), progression-free survival, and disease-specific survival were seen between the MSI-H and POLE-mutant cohorts. Within the MSI-H cohort, there were statistically significant differences in TMB and stage at presentation across FIGO grades, but not survival. Within the POLE-mutant cohort, there was significantly greater TMB with increasing FIGO grade, but there were no significant differences in stage or survival. In both the MSI-H and POLE-mutant cohorts, log-rank survival analysis showed no statistically significant difference in progression-free and disease-specific survival across FIGO grades. Similar findings were also seen when a binary grading system was utilized. Since FIGO grade was not associated with survival, we conclude that the intrinsic biology of these tumors, characterized by their molecular profile, may override the significance of FIGO grading.

Localized Endometrial Proliferations of Pregnancy are Clonal Glandular Outgrowths Characterized by PTEN Loss and PIK3CA Pathogenic Variants

Gestational endometrium can demonstrate a spectrum of atypical but benign changes. One such lesion is localized endometrial proliferation of pregnancy (LEPP), first described in a series of 11 cases. To understand its biological and clinical importance, we explore the pathologic, immunophenotypic, and molecular features of this entity. Nine cases of LEPP identified in 15 years were retrieved from departmental archives and reviewed. Immunohistochemistry and next-generation sequencing using a comprehensive 446-gene panel were performed when the material was available. Eight cases were identified in curettage specimens performed after first-trimester pregnancy loss, and 1 in the basal plate of a mature placenta. The mean patient age was 35 (range 27-41) years. The mean lesion size was 6.3 (range 2-12) mm. Architectural patterns, often coexisting in the same case, included cribriform (n = 7), solid (n = 5), villoglandular (n = 2), papillary (n = 2), and micropapillary (n = 1). Cytologic atypia was mild in 7 cases and moderate in 2. Mitotic activity was low (up to 3 per 2.4 mm

Highly Sensitive Microsatellite Instability and Immunohistochemistry Assessment in Endometrial Aspirates as a Tool for Cancer Risk Individualization in Lynch Syndrome

Women with Lynch syndrome (LS) are at increased risk of endometrial cancer (EC), among other tumors, and are characterized by mismatch repair (MMR) deficiency and microsatellite instability (MSI). While risk-reducing gynecologic surgeries effectively decrease EC incidence, doubts arise regarding the appropriate timing of the surgery. We explored the usefulness of highly sensitive MSI (hs-MSI) assessment in endometrial aspirates for individualizing gynecologic surveillance in LS carriers. Ninety-three women with LS, 25 sporadic EC patients (9 MMR-proficient and 16 MMR-deficient), and 30 women with benign gynecologic disease were included in this study. hs-MSI was assessed in prospectively collected endometrial aspirates in 67 LS carriers, EC cases, and controls. MMR, PTEN, ARID1A, and PAX2 protein expression patterns were evaluated in the LS samples. Follow-up aspirates from 8 LS carriers were also analyzed. Elevated hs-MSI scores were detected in all aspirates from MMR-deficient EC cases (3 LS and 16 sporadic) and negative in aspirates from controls and MMR-proficient EC cases. Positive hs-MSI scores were also detected in all 4 LS aspirates reported as complex hyperplasia. High hs-MSI was also present in 10 of 49 aspirates (20%) from LS carriers presenting a morphologically normal endometrium, where MMR protein expression loss was detected in 69% of the samples. Interestingly, the hs-MSI score was positively correlated with MMR-deficient gland density and the presence of MMR-deficient clusters, colocalizing PTEN and ARID1A expression loss. High hs-MSI scores and clonality were evidenced in 2 samples collected up to 4 months before EC diagnosis; hs-MSI scores increased over time in 5 LS carriers, whereas they decreased in a patient with endometrial hyperplasia after progestin therapy. In LS carriers, elevated hs-MSI scores were detected in aspirates from premalignant and malignant lesions and normal endometrium, correlating with MMR protein loss. hs-MSI assessment and MMR immunohistochemistry may help individualize EC risk assessment in women with LS.

SOX17: A Highly Sensitive and Specific Immunomarker for Ovarian and Endometrial Carcinomas

PAX8 is the most commonly used immunomarker to link a carcinoma to the gynecologic tract; however, it lacks specificity. Through mining The Cancer Genome Atlas mRNA expression profile data, we identified SOX17 as a potential specific marker at the mRNA level for gynecologic tumors. To evaluate the utility of this marker in the identification of the gynecologic origin of a given carcinoma, we performed immunochemical staining in a large cohort of ovarian and endometrial cancer cases (n = 416), together with a large cohort of solid tumors from other organs (n = 1544) in tissue microarrays. Similar to PAX8, SOX17 was highly expressed in different subtypes of ovarian carcinoma (97.5% for SOX17 vs 97% for PAX8 in serous carcinoma, 90% vs 90% in endometrioid carcinoma, and 100% vs 100% in clear cell carcinoma), except for mucinous carcinoma (0% vs 27%), and was also highly expressed in different subtypes of endometrial carcinoma (88% vs 84% in endometrioid carcinoma, 100% vs 100% in serous and clear cell carcinoma). SOX17 was not expressed in thyroid and renal cell carcinomas, whereas PAX8 expression was high (86% and 85%, respectively). In addition, SOX17 was expressed at low levels in cervical adenocarcinoma (20%) and had no expression in cervical squamous carcinoma, mesothelioma, and carcinomas from the breast, lung, pancreas, colon, stomach, liver, bladder, and salivary gland. Our data indicate that SOX17 is not only a sensitive but also a specific marker for the origin of ovarian and endometrial carcinomas.

ARID1A Regulates Progesterone Receptor Expression in Early Endometrial Endometrioid Carcinoma Pathogenesis

Loss of progesterone receptor (PR) expression is an established risk factor for unresponsiveness to progesterone therapy in patients with endometrial atypical hyperplasia and endometrioid carcinoma. ARID1A is one of the most commonly mutated genes in endometrioid carcinomas, and the loss of its expression is associated with tumor progression. In this study, we investigated the roles of ARID1A deficiency in PR expression in human and murine endometrial epithelial neoplasia. An analysis of genome-wide chromatin immunoprecipitation sequencing in isogenic ARID1A-/- and ARID1A+/+ human endometrial epithelial cells revealed that ARID1A-/- cells showed significantly reduced chromatin immunoprecipitation sequencing signals for ARID1A, BRG1, and H3K27AC in the PgR enhancer region. We then performed immunohistochemistry to correlate the protein expression levels of ARID1A, estrogen receptor, and PR in 50 human samples of endometrial atypical hyperplasia and 75 human samples of endometrial carcinomas. The expression levels of PR but not were significantly lower in ARID1A-deficient low-grade endometrial carcinomas and atypical hyperplasia (P = .0002). When Pten and Pten/Arid1a conditional knockout murine models were used, Pten-/-;Arid1a-/- mice exhibited significantly decreased epithelial PR expression in endometrial carcinomas (P = .003) and atypical hyperplasia (P < .0001) compared with that in the same tissues from Pten-/-;Arid1a+/+ mice. Our data suggest that the loss of ARID1A expression, as occurs in ARID1A-mutated endometrioid carcinomas, decreases PgR transcription by modulating the PgR enhancer region during early tumor development.

Identifying SOX17 as a Sensitive and Specific Marker for Ovarian and Endometrial Carcinomas

Similar to PAX8, SOX17 was recently identified as a master transcription factor of ovarian cancer based on RNA sequencing data. We explored SOX17 utility in diagnosing ovarian tumors and other gynecologic tumors. We systematically evaluated SOX17 expression on tissue microarrays of 398 ovarian tumors of various types, 93 endometrial carcinomas, 80 cervical carcinomas, and 1371 nongynecologic carcinomas, such as those of kidney, thyroid, breast, colon, bladder, liver, bile duct, adrenal gland, pancreas, brain, and lung and malignant melanoma. In addition, we evaluated SOX17 expression in whole tissue sections from 60 gynecologic carcinomas and 10 angiosarcomas. The results demonstrated that SOX17 was highly expressed in most ovarian and endometrial tumors with strong intensity. However, unlike PAX8, it was predominately negative in other tested tumor types, including kidney and thyroid tumors. In particular, SOX17 was highly expressed in the following pathologic subtypes of ovarian tumors: serous carcinoma, clear cell carcinoma, endometrioid carcinoma, and germ cell tumors. SOX17 was mostly negative in mucinous carcinoma and sex cord stromal tumors. In addition, SOX17 was expressed in vascular endothelial cells and was positive in all tested angiosarcomas. In summary, our results demonstrate that SOX17 is a sensitive and specific marker for ovarian nonmucinous carcinomas and endometrial carcinomas. For ovarian germ cell tumors and angiosarcomas, SOX17 demonstrates higher specificity than PAX8, with comparable sensitivity. Furthermore, SOX17 positivity in endothelial cells serves as an internal positive control, making it an excellent marker.

High-Grade Endometrial Stromal Sarcomas With YWHAE::NUTM2 Gene Fusion Exhibit Recurrent CDKN2A Alterations and Absence of p16 Staining is a Poor Prognostic Marker

High-grade endometrial stromal sarcomas (HGESSs) are aggressive uterine tumors harboring oncogenic fusion proteins. We performed a molecular study of 36 HGESSs with YWHAE::NUTM2 gene fusion, assessing co-occurring genetic events, and showed that these tumors frequently harbor recurrent events involving the CDKN2A locus on chromosome 9p. Using array-based copy number profiling and CDKN2A fluorescence in situ hybridization, we identified homozygous and hemizygous deletions of CDKN2A in 18% and 14% of tumors (n = 22 analyzed), respectively. While all YWHAE-rearranged HGESSs with retained disomy for CDKN2A were immunohistochemically positive for p16INK4 (p16), all tumors with homozygous deletion of CDKN2A showed complete absence of p16 staining. Of the 2 tumors with a hemizygous deletion of CDKN2A, 1 showed diffuse and strong p16 positivity, whereas the other showed complete absence of staining. In the p16-negative case, we did not find intragenic mutations or DNA promoter methylation to explain the p16 protein loss, implicating other mechanisms in the regulation of protein expression. In our cohort, subclonal or complete absence of p16 staining was associated with worse overall survival compared with positive p16 staining (1-year overall survival: 28.6% vs 90.7%, respectively; n = 32; P < .001), with all 7 patients in the p16-negative group having succumbed to their disease within 2 years of diagnosis. Our results suggested CDKN2A alterations as a cooperative driver of tumorigenesis in a subset of HGESSs with the YWHAE::NUTM2 gene fusion and showed p16 to be a potential prognostic marker.

Grade and Estrogen Receptor Expression Identify a Subset of No Specific Molecular Profile Endometrial Carcinomas at a Very Low Risk of Disease-Specific Death

Endometrial carcinoma (EC) can be divided into 4 prognostic molecular subtypes, and no specific molecular profile (NSMP) type is the most commonly occurring type (∼50%). Although described as having an intermediate to favorable prognosis, this subtype encompasses pathologically and molecularly diverse tumors. We aimed to identify factors associated with outcomes within the NSMP ECs that might be used to stratify prognosis and direct treatment. Clinicopathologic, immunohistochemical, and genetic features of a large series of NSMP EC were used to identify parameters that could identify the subset associated with a very favorable outcome (disease-specific death rate 1%], 84% of cases), which showed a 5-year disease-specific death rate of 1.6% across all stages and 1.4% within stage I. The remaining cases (high-risk NSMPs, grade 3, and/or ER-negative status) were responsible for most of the disease-specific deaths (disease-specific death rate at 5 years, 22.9%; hazard ratio compared with that of low-risk NSMPs: 16.3; 95% CI, 8.4-31.7). Within NSMP EC, the low-risk and high-risk categories were of prognostic significance independent of the stage on a multivariate analysis. Low-grade and ER-positive NSMP ECs are a homogeneous low-risk group associated with an exceptionally favorable prognosis in which de-escalation and/or endocrine therapy strategies can be applied. Grade 3 and/or ER-negative status identifies a high-risk NSMP subset, including rare high-grade histotypes (eg, clear cell, dedifferentiated, and mesonephric-like), responsible for most NSMP-related deaths. Subclassification of NSMPs allows for the category of low-risk EC molecular subtypes to be dramatically expanded because it now includes both POLEmut and the much more common low-risk NSMP EC.

HER2-amplified endometrial carcinoma and AFP-producing endometrial carcinoma

Adult NTRK-rearranged spindle cell neoplasms of the viscera: with an emphasis on rare locations and heterologous elements

NTRK-rearranged mesenchymal neoplasms mostly affect the soft tissues of pediatric patients. Given the responsiveness to selective NTRK inhibitors, it remains critical to identify those ultra-rare cases occurring in the viscera of adults. In five females and two males aged 18-53 years, we characterized visceral mesenchymal tumors harboring TPM3-NTRK1 [uterine cervix (N = 2), pleura, prostate], LMNA-NTRK1 (lung), SQSTM1-NTRK3 (heart), and NTRK3 rearrangement with unknown fusion partner (colon/mesocolon) with RNA sequencing, FISH, RT-PCR, and immunohistochemistry. The tumors exhibited spindled to ovoid/epithelioid or pleomorphic cells, often arranged in fascicles, and were low-to-intermediate-grade and high-grade in three and four cases, respectively. Keloid-like stromal collagen and perivascular hyalinization was noted in five. Adenosarcoma-like appearances were observed in two, manifesting frond-like protrusions in one cervical tumor and phyllodes-like architecture in the prostatic tumor. Abrupt high-grade transformation into pleomorphic liposarcoma was found in another cervical tumor, while the pleural tumor contained intermixed rhabdomyoblasts. Pan-TRK immunostaining was positive in all cases. All cases expressed CD34, while five were S100-positive. CDKN2A homozygous deletion with concomitant p16 loss occurred in 4/7. Whole-exome sequencing identified TP53 mutation (c.672+2T>C, involving a splice site, with concomitant protein loss) in a cervical sarcoma, limited to its heterologous liposarcomatous component. At least moderate pan-TRK immunoreactivity was present in varying proportions of potential pathologic mimics, with BCOR-positive sarcoma (56%, 5/9), undifferentiated uterine sarcoma (50%, 3/6), and spindle cell/sclerosing rhabdomyosarcoma (33%, 2/6) being among the most frequent. This underscored the unsatisfactory specificity of pan-TRK immunohistochemistry and warranted molecular confirmation in the diagnosis of adult NTRK-rearranged visceral mesenchymal neoplasms. The current report highlights the ever-expanding clinicopathologic and genetic spectrum of this entity by describing the unprecedented cardiac and pleural locations and heterologous differentiation, as well as the second NTRK-rearranged "prostatic stromal sarcoma," while substantiating CDKN2A deletion as a frequent occurrence.

Histopathologic features and molecular genetic landscape of HER2-amplified endometrial carcinomas

HER2 is an established therapeutic biomarker in advanced or recurrent endometrial serous carcinoma. Current clinical guidelines recommend HER2 testing exclusively in this endometrial carcinoma (EC) subtype; however, the full spectrum of ECs harboring HER2 amplification remains ill-defined. The present study characterizes the clinicopathologic and molecular features of HER2-amplified ECs across all histologic subtypes. Retrospective analysis of our institutional cohort of 2,042 ECs subjected to targeted clinical massively parallel sequencing identified 77 (3.8%) cases with HER2 amplification, a group comprised of serous (n = 29), endometrioid (low-grade, n = 2, high-grade, n = 1) and clear cell (n = 4) carcinomas, carcinosarcomas (n = 18) and high-grade ECs with ambiguous features (HGEC, n = 23). A co-existing TP53 mutation was identified in 94% (72/77) of HER2-amplified ECs. Other recurrent genetic alterations included amplification of CCNE1 (22%) and ERBB3 (10%), FBXW7 mutations or deletions (13%), and mutations in PIK3CA (40%) and PPP2R1A (13%). The HER2 immunohistochemistry score was 2+ or 3+ for all evaluable cases (n = 61). Apart from carcinosarcomas, which often showed lower HER2 expression, particularly in the sarcomatous component, HER2 immunohistochemical staining pattern and intensity were similar across EC subtypes. Intratumor heterogeneity in HER2 expression was common and correlated with genetic heterogeneity as detected by fluorescence in-situ hybridization. These results demonstrate the frequent co-occurrence of HER2 amplification with TP53 mutation and high-grade histology, rather than being specific to serous carcinoma, per se. Overall, these findings suggest that HER2 targeted therapy may be more broadly applicable to all high-grade EC histotypes and consideration should be given to expanding therapeutic eligibility.

Prospective molecular classification of endometrial carcinomas: institutional implementation, practice, and clinical experience

The comprehensive genomic analysis of endometrial carcinoma (EC) by The Cancer Genome Atlas (TCGA) led to the discovery of four distinct and prognostically significant molecular subgroups. Molecular classification has the potential to improve risk-stratification when integrated with clinicopathologic features and has recently been included in national and international patient management EC guidelines. Thus, the adoption of molecular classification into routine pathologic and clinical practice is likely to grow significantly in the upcoming years. Establishing an efficient and standardized workflow for performing molecular classification on ECs, and reporting both the molecular and histologic findings in an integrative manner, is imperative. Here we describe our effort to implement rapid and routine molecular classification on all ECs diagnosed at our institution. To this effect, we performed immunohistochemistry as a surrogate marker for identifying genetic and/or epigenetic alterations in DNA mismatch repair (e.g., MLH1, PMS2, MSH6, MSH2), and TP53 genes. In addition, we have developed and employed a single-gene POLE SNaPshot assay, which is a rapid and analytically sensitive method for detecting select POLE exonuclease domain mutations (EDMs). We report our molecular testing workflow and integrative reporting system as well as the clinicopathologic and molecular features of 310 ECs that underwent routine molecular classification at our institution. The 310 ECs were molecularly classified as follows: 15 (5%) POLE mutant (POLEmut), 79 (25%) mismatch repair-deficient (MMRd), 135 (44%) no specific molecular profile (NSMP), and 81 (26%) p53 abnormal (p53abnl). This work provides an initial framework for implementing routine molecular classification of ECs.

Prognostic implications of tumor-infiltrating T cells in early-stage endometrial cancer

Patients with endometrial cancer differ in terms of the extent of T-cell infiltration; however, the association between T-cell subpopulations and patient outcomes remains unexplored. We characterized 285 early-stage endometrial carcinoma samples for T-cell infiltrates in a tissue microarray format using multiplex fluorescent immunohistochemistry. The proportion of T cells and their subpopulations were associated with clinicopathological features and relapse-free survival outcomes. CD3+ CD4+ infiltrates were more abundant in the patients with higher grade or non-endometrioid histology. Cytotoxic T cells (CD25+, PD-1+, and PD-L1+) were strongly associated with longer relapse-free survival. Moreover, CD3+ PD-1+ stromal cells were independent of other immune T-cell populations and clinicopathological factors in predicting relapses. Patients with high stromal T-cell fraction of CD3+ PD-1+ cells were associated with a 5-year relapse-free survival rate of 93.7% compared to 79.0% in patients with low CD3+ PD-1+ fraction. Moreover, in patients classically linked to a favorable outcome (such as endometrioid subtype and low-grade tumors), the stromal CD3+ PD-1+ T-cell fraction remained prognostically significant. This study supports that T-cell infiltrates play a significant prognostic role in early-stage endometrial carcinoma. Specifically, CD3+ PD-1+ stromal cells emerge as a promising novel prognostic biomarker.

Targeted RNA expression profiling identifies high-grade endometrial stromal sarcoma as a clinically relevant molecular subtype of uterine sarcoma

High-grade endometrial stromal sarcoma (HGESS) may harbor YWHAE-NUTM2A/B fusion, ZC3H7B-BCOR fusion, and BCOR internal tandem duplication (ITD). NTRK3 upregulation and pan-Trk expression were reported in soft tissue lesions that share similar morphology and genetic abnormalities. To confirm these findings in HGESS, differential expression analysis was performed at gene level comparing 11 HGESS with 48 other uterine sarcomas, including 9 low-grade endometrial stromal sarcomas, 23 undifferentiated uterine sarcomas, and 16 leiomyosarcomas, using targeted RNA sequencing data. Pan-Trk immunohistochemistry was performed on 35 HGESS, including 10 tumors with RNA expression data, with genotypes previously confirmed by targeted RNA sequencing, fluorescence in situ hybridization, and/or genomic PCR. Unsupervised hierarchical clustering of the top 25% of differentially expressed probes identified three molecular groups: (1) high NTRK3, FGFR3, RET, BCOR, GLI1, and PTCH1 and low ESR1 expression; (2) low NTRK3, FGFR3, RET, BCOR, GLI1, and PTCH1 and high ESR1 expression; and (3) low NTRK3, FGFR3, RET, BCOR, GLI1, PTCH1, and ESR1 expression. Among HGESS, 64% of tumors clustered in group 1, while 27% clustered in group 2. Cytoplasmic and/or nuclear pan-Trk staining of variable extent and intensity was seen in 91% of HGESS regardless of cyclin D1 and/or BCOR positivity. ER and PR expression was seen in 44% of HGESS despite ESR1 downregulation. Two patients with ER and PR positive but ESR1 downregulated stage I HGESS were treated with endocrine therapy, and both recurred at 12 and 36 months after primary resection. By RNA expression, HGESS appear homogenous and distinct from other uterine sarcomas by activation of kinases, including NTRK3, and sonic hedgehog pathway genes along with downregulation of ESR1. Most HGESS demonstrate pan-Trk staining which may serve as a diagnostic biomarker. ESR1 downregulation is seen in some HGESS that express ER and PR which raises implications in the utility of endocrine therapy in these patients.

Recurrent urothelial carcinoma-like FGFR3 genomic alterations in malignant Brenner tumors of the ovary

Malignant Brenner tumor is a rare primary ovarian carcinoma subtype that may present diagnostic and therapeutic conundrums. Here, we characterize the genomics of 11 malignant Brenner tumors, which represented 0.1% of 14,153 clinically advanced ovarian carcinomas submitted for genomic profiling during the course of clinical care. At the time of molecular profiling, there was no evidence of a primary urothelial carcinoma of the urinary tract in any case. Cases with transitional-like morphologic features in the setting of variant ovarian serous or endometrioid carcinoma morphology were excluded from the final cohort. Malignant Brenner tumors exhibited CDKN2A/2B loss and oncogenic FGFR1/3 genomic alterations in 55% of cases, respectively; including recurrent FGFR3 S249C or FGFR3-TACC3 fusion in 45% of cases. FGFR3-mutated cases had an associated benign or borderline Brenner tumor pre-cursor components, further confirming the diagnosis and the ovarian site of origin. Malignant Brenner tumors were microsatellite stable, had low tumor mutational burden and exhibited no evidence of homologous recombination deficiency. PIK3CA mutations were enriched with FGFR3 alterations, while FGFR3 wild-type cases featured MDM2 amplification or TP53 mutations. The FGFR3 S249C short variant mutation was absent in 14,142 non-Brenner, ovarian carcinomas subtypes. In contrast to malignant Brenner tumors, FGFR1/2/3 alterations were present in ~5% of non-Brenner, ovarian serous, clear cell and endometrioid carcinoma subtypes, most often as FGFR1 amplification in serous carcinoma or FGFR2 short variant alterations in clear cell or endometrioid carcinomas, respectively. Finally, malignant Brenner tumors had overall distinct genomic signatures compared to FGFR-mutated ovarian serous, endometrioid, and clear cell carcinoma subtypes. This study provides insights into the molecular pathogenesis of malignant Brenner tumors, contrasts the extent of FGFR1/2/3 alterations in ovarian serous, clear cell and endometrioid carcinomas and emphasizes the potential value of novel and FDA-approved, anti-FGFR inhibitors, such as erdafitinib and pemigatinib, in refractory, FGFR3-mutated malignant Brenner tumors.

High-grade transformation of low-grade endometrial stromal sarcomas lacking YWHAE and BCOR genetic abnormalities

High-grade histologic transformation of low-grade endometrial stromal sarcoma (LGESS) is rare. Here, we describe the clinicopathologic features and gene fusion status of 12 cases (11 primary uterine corpus and 1 primary vaginal), 11 diagnosed prospectively from 2016, and 1 retrospectively collected. Targeted RNA sequencing and/or fluorescence in situ hybridization was employed in all cases. High-grade transformation was seen at the time of initial diagnosis in eight patients and at the time of recurrence in four patients, 4-11 years after initial diagnosis of LGESS. High-grade morphology consisted of generally uniform population of round to epithelioid cells with enlarged nuclei one to two times larger than a lymphocyte, visible nucleoli, and increased mitotic index (range, 6-30; median, 16 per 10 high-power fields); there was often an associated sclerotic and/or myxoid stroma. Estrogen receptor, progesterone receptor, and CD10 expression was absent or significantly decreased (compared with the low-grade component) in the high-grade foci of five tumors. One tumor demonstrated positive (diffuse and strong) cyclin D1 and BCOR staining. p53 staining was wild type in both components of all eight tumors tested. JAZF1-SUZ12 (n = 6), JAZF1-PHF1 (n = 3), EPC1-PHF1, (n = 1), or BRD8-PHF1 (n = 1) fusions were detected in 11 tumors; no fusions were found in one by targeted RNA sequencing. Patients presented with FIGO stages I (n = 4), II (n = 4), III (n = 1), and IV disease (n = 2). Median overall survival calculated from the time of histologic transformation was 22 months (range, 8 months to 8 years) with five patients who died of disease 8-18 months after transformation. High-grade transformation may occur in LGESS with JAZF1 and PHF1 rearrangements at the time of or years after initial diagnosis. Such high-grade transformation is characterized by nuclear enlargement, prominent nucleoli, and increased mitotic index compared with typical LGESS. Histologic high-grade transformation may herald aggressive behavior.

Spatial Evaluation and Prognostic Significance of V-Domain Immunoglobulin Suppressor of T-Cell Activation (VISTA) in Human Resectable Cervical Carcinoma: Implications for Immune Activation and Suppression

V-domain immunoglobulin suppressor of T-cell activation (VISTA) is a promising next-generation immune checkpoint target. This study investigated the distribution and clinical significance of VISTA expression in cervical carcinoma. Using a cohort of 290 patients from Sun Yat-sen Memorial Hospital, we assessed VISTA expression in tumor cells, endothelial cells, and immune cells (ICs) through immunohistochemistry, and found that it was expressed in tumor cells (18.6%), endothelial cells (38.3%), and ICs (100%). Higher infiltration of VISTA

An Exploratory Application of a Central Nervous System (CNS) Tumor Methylation Classifier in Ovarian Neuroectodermal Tumors

Ovarian neuroectodermal tumors (NETs) are rare malignancies with unclear diagnostic criteria and challenging treatment. We aimed to assess the utility of DNA methylation in the diagnostic classification and prognostic stratification of ovarian NETs. This retrospective study included 15 patients diagnosed with ovarian NETs at Peking Union Medical College Hospital between 2010 and 2024. Paraffin-embedded tumor tissues from all patients underwent clinicopathologic review, DNA methylation microarray assay, EWSR1 fluorescence in situ hybridization, and immunohistochemistry. The median age at diagnosis of ovarian NETs was 19 years (range, 9-73 years). These tumors often displayed nonspecific clinical manifestations and were frequently diagnosed at an advanced stage. Morphologic diagnosis included 3 medulloblastoma, 1 neuroblastoma, 3 embryonal tumors with multilayered rosettes (ETMRs), 3 ependymomas, 1 high-grade glioma, 1 gliosarcoma, 1 low-grade neuronal-glial tumor, and 2 tumors that cannot be specified. A teratoma background was present in 73.3% (11/15) of the cases. None of the tumors exhibited EWSR1 gene rearrangement. Methylation classification was consistent with morphologic diagnosis in 30% of patients (5/15). A novel ETMR, non-C19MC-altered type ovarian tumor was identified in 3 patients. The median follow-up period of all patients was 14.9 months (range, 2.1-216.4 months), during which 60.0% of patients experienced recurrence or disease progression, and the mortality rate was 33.3%. Patients with ETMR non-C19MC-altered subtype and unmatched tumors exhibited extremely poor outcomes, with 80% (4/5) mortality within 12 months. DNA methylation profiling classified a subset of ovarian NETs into molecular subtypes resembling those of central nervous system (CNS) tumor counterparts, with corresponding prognostic similarities. Leveraging the CNS tumor methylation classifier to diagnose peripheral neuroectodermal tumors may offer critical clinical insights for these rare malignancies, enabling molecular subtyping, prognostication, and alignment with CNS-targeted therapeutic strategies.

Cervical Human Papillomavirus–Independent Squamous Cell Carcinoma: A Clinicopathological Review and Outcomes Analysis Compared With Human Papillomavirus–Associated Squamous Cell Carcinoma

Human papillomavirus (HPV)-independent cervical squamous cell carcinomas (HPVI SCCs) represent a poorly characterized entity. We aimed to explore the clinicopathological and survival features in the largest series of HPVI SCCs and compare them to HPV-associated (HPVA) SCCs. Eighty-nine cases of SCC previously tested negative for high-risk and low-risk HPV were collected from 22 institutions. A total of 363 HPVA SCCs were retrieved from a previously published database. Demographic and clinicopathological features, including p16 and p53 immunohistochemistry, and follow-up data were recorded. Forty-nine of 89 cases were classified as "true" HPVI SCC (HPV-/p16-), whereas 40 were equivocal HPVI SCC (HPV-/p16+ or HPV-/p16 not performed) and were excluded. The median age of true HPVI SCCs was 68 (range, 36-88) years and 38 (77.6%) patients were diagnosed aged 60 years or older. Seven (14.2%) had a history of uterine prolapse. Compared with HPVA SCC, patients with HPVI SCCs were older (P < .001), had larger tumors (P < .001), were diagnosed at higher Federation of Gynecology and Obstetrics stage (P < .001), recurred more frequently (P < .001) and had worse survival (P < .001). True HPVI SCCs also more frequently had keratinizing histology (P = .001) and abnormal p53 (P < .001). In a bivariate analysis adjusted for Federation of Gynecology and Obstetrics stage, HPVI p53-abnormal SCC had a higher risk of recurrence (P = .068; P < .001) and death of disease (P = .062; P < .001) than HPVI p53-wild type SCC and HPVA SCC. Survival outcomes (recurrence and disease-specific survival) in HPVI SCC and HPVA SCC differed significantly when comparing surgically treated HPVI SCC and HPVA SCC (P < .0001 for both). Even with the challenges associated with an analysis of a heterogeneous study set, we confirm that HPVI cervical SCCs have distinctive clinicopathological features. p53-Abnormal and p53-wild type HPVI SCC neoplasms exist in the uterine cervix, and p53-abnormal tumors are more aggressive. Although HPVI SCC is more frequently keratinizing than HPVA SCC neoplasms, there is substantial morphologic overlap, so HPV testing (or p16 at least) and p53 should be considered in cervical SCC, especially in patients over the age of 60 years.

Methylation Signatures Identify Two Distinct Clusters of Uterine Leiomyosarcoma With Unique Histologic and Clinical Behaviors

Uterine leiomyosarcoma (uLMS) is a rare and deadly gynecologic malignancy. uLMS is histologically heterogeneous and presents with a wide spectrum of tumor differentiation, with a broad range of genomic DNA instability, which can make the diagnosis and prognosis of uLMS challenging. Methylation has emerged as a useful molecular tool in tumor classification and diagnosis in certain neoplasms. We initiated this study to investigate the role of global methylation in the differential diagnosis of uLMS from its mimics in correlation with pathologic characteristics and clinical outcomes. In this study, we performed array-based global methylation profiling analysis in a total of 71 uLMS and compared the methylation signatures of uLMS with several other uterine mesenchymal tumors and soft tissue leiomyosarcoma. We found that uLMS demonstrated distinct methylation patterns differing from all other tumor types. Notably, methylation profiling defines 2 distinct subgroups of uLMS with differing copy number alterations, resulting in unique histologic and clinical behaviors, further emphasized by differences in methylation pathway analysis. This study is the first to report methylation profiling as a useful diagnostic tool in differentiating uLMS from mimics and defines 2 subtypes of uLMS based on methylation signatures.

Comparative Analysis Reveals Recurrent Molecular Alterations in Low-Risk Human Papillomavirus 6 and Human Papillomavirus 11-Associated Squamous Cell Carcinoma of the Uterine Cervix and Vulva

Although the association between human papillomavirus (HPV) 6 and HPV11 and squamous cell carcinomas (SCCs) has been well documented, the molecular alterations and mechanisms by which these low-risk HPVs contribute to carcinogenesis remain largely unknown. In this study, we comparatively elucidated the molecular landscape of HPV6/11-associated condylomas (9 cases) and SCCs (8 cases) of the uterine cervix and vulva. Sixteen of 17 cases were successfully analyzed using deep next-generation sequencing. Recurrent molecular alterations in the SCCs included mutations in the TERT promoter (pTERT, 71%), NOTCH1 (57%), NFE2L2 (57%), NOTCH3 (29%), and CDKN2A (29%). Mutations in NOTCH1 and NFE2L2 tended to be mutually exclusive. Less common somatic mutations were each detected in the following genes: AR, ARID1A, ASXL1, BCORL1, DAZAP1, FNDC1, HRAS, KMT2B, NOTCH2, NRAS, PIK3R1, and TP53. Etiologically similar to the SCCs, the vast majority of vulvar and cervical condylomas (7/9, 78%) were infected with HPV6 rather than HPV11. Unlike the SCCs, condylomas rarely harbored recurrent pathogenic somatic mutations. NOTCH1 and NOTCH2 were the only mutant genes detected in both SCCs and condylomas in this series, suggesting a critical role for the NOTCH pathway in the initiation and maintenance of HPV6/11-related early squamous lesions. Although pathogenic mutations in NOTCH1, NOTCH2, ERBB3, ATRX, FGFR2, EPHA5, CARD11, STAG2, and TSC2 were detected in condylomas, none were recurrent, indicating diverse genetic alterations involved in the development of these lesions. Case 8 illustrated a stepwise progression from condyloma to invasive SCC, in which pathogenic mutations in pTERT and NOTCH1 were detected in the SCC (age 58) and the condyloma at age 55, but not in the condyloma at age 44. Our study presents the first report on the molecular landscape of HPV6/11-associated SCCs of the uterine cervix and vulva. We provide evidence that SCCs associated with low-risk HPV are distinct entities, differing from those related to high-risk HPV and more closely resembling HPV-independent neoplasms. Given that low-risk HPV-associated SCCs of the cervix and vulva exhibit unique morphological and molecular features, they should either be described separately within existing classification systems or classified as a distinct new entity.

Deep Learning-Assisted System Improves Practical Effects in Cervical Cytopathology Diagnosis: A Comparative Study of Reading Modes

Deep learning (DL) has significantly improved the diagnostic accuracy and efficiency of cytopathologists. However, current DL-assisted reading modes have yet to be fully evaluated, and there is limited evidence regarding cytopathologists' preferences and experiences. This study employs a randomized, controlled, 4-way crossover design to assess the effectiveness of 4 distinct cytopatholog reading modes. This study included retrospectively collected 1620 cervical slides between 2021 and 2022. These slides were read by 108 certified cytopathologists with varying expertise using the 4 reading modes: unassisted, concurrent, second, and triage mode. A questionnaire survey was conducted to gather the cytopathologists' adoption of each mode, including mode score and their confidence and preferences. Compared with unassisted, all DL-assisted modes improved the cytopathologists' diagnostic performance. The unassisted mode had a sensitivity of 66.2% and a specificity of 72.5%. The second, concurrent, and triage modes all improved on these metrics: sensitivity increased by 20.2%, 17.3%, and 16.7%, respectively, whereas specificity increased by 13.2%, 10.8%, and 22.3%, respectively. The median reading time per slide was prolonged in second mode from 200 to 235 seconds but substantially reduced to 130 seconds in triage mode, and 53 seconds in concurrent mode (P 90% of cytopathologists agreed that the DL-assisted mode was useful in improving diagnostic confidence, and they preferred the concurrent mode, whereas the triage mode achieved the highest performance in the mode score. The second mode stands out for its heightened sensitivity, the triage mode boasts superior specificity, and the concurrent mode leads in efficiency when assisting cytopathologists. These findings provide useful information for choosing appropriate DL-assisted modes in cytopathological practice.

Detection of FOXL2 C134W Mutation Status by a Novel BaseScope In Situ Hybridization Assay is Highly Sensitive and Specific for Adult Granulosa Cell Tumors

Adult granulosa cell tumors (AGCTs) are a molecularly distinct group of malignant ovarian sex cord-stromal tumors (SCSTs) characterized by a nearly ubiquitous c.402C>G/p.C134W mutation in FOXL2 (hereafter referred to as "C134W"). In some cases, AGCT exhibits marked morphologic overlap with other SCSTs and has an identical immunophenotype, and molecular testing may be necessary to help confirm the diagnosis. However, molecular testing is time consuming, relatively expensive, and unavailable in many pathology laboratories. We describe the development and validation of an in situ hybridization (ISH) custom BaseScope assay for the detection of the FOXL2 C134W mutation. We evaluated 106 ovarian SCSTs, including 78 AGCTs, 9 juvenile granulosa cell tumors, 18 fibromas (cellular and conventional), and 1 SCST, not otherwise specified, as well as 53 epithelial ovarian tumors (42 endometrioid carcinomas and 11 carcinosarcomas) and 1 STK11 adnexal tumor for the presence or absence of FOXL2 wild-type and FOXL2 C134W RNA expression via BaseScope-ISH. Fifty-one tumors had previously undergone DNA sequencing of the FOXL2 gene. Across the entire cohort, the FOXL2 C134W probe staining was positive in 77 of 78 (98.7%) AGCTs. Two of 81 (2.5%) non-AGCTs also showed positive staining, both of which were epithelial ovarian tumors. The assay worked in tissue from blocks >20 years old. There was 100% concordance between the FOXL2 sequencing and BaseScope-ISH results. Overall, assessment of FOXL2 mutation status by custom BaseScope-ISH demonstrated 98.7% sensitivity and 97.5% specificity for the diagnosis of AGCT. BaseScope-ISH for FOXL2 C134W represents a reasonable alternative to sequencing, is quicker and less expensive, and is more easily incorporated than molecular testing into many pathology laboratories. It also has the advantage of requiring less tissue, and the neoplastic cells can be directly visualized on stained sections.

Testicular Neoplasms With Sex Cord and Stromal Components Harbor a Recurrent Pattern of Chromosomal Gains

A small subset of testicular sex cord-stromal tumors, designated as Sertoli-stromal cell tumors (SSCTs), comprises a mixture of Sertoli, spindle, and/or Leydig cells. The clinicopathologic features of these tumors have not been studied in any detail, and their molecular features are unknown. We, therefore, assessed the morphologic and genomic features of 14 SSCTs, including 1 tumor with features similar to the ovarian Sertoli-Leydig cell tumor (SLCT) with retiform tubules. The median age of the patients was 24 years (range, 10-55 years), and the median tumor size was 2.3 cm (range, 0.7-4.7 cm). All tumors showed Sertoli-like sex cord cells arranged in variably developed tubular structures, typically also forming nests and cords. These imperceptibly blended with a neoplastic spindle cell stroma or, in the SLCT, vacuolated to eosinophilic Leydig cells. Genomic analysis demonstrated the presence of a hotspot loss-of-function DICER1 mutation in the SLCT (patient 1) and hotspot gain-of-function CTNNB1 mutations in the tumors of patients 2 and 3, with both CTNNB1 variants being interpreted as possible subclonal events. The mutations were the only relevant findings in the tumors of patients 1 and 2, whereas the tumor of patient 3 harbored concurrent chromosomal arm-level and chromosome-level copy number gains. Among the remaining 11 tumors, all of those that had interpretable copy number data (9 tumors) harbored multiple recurrent chromosomal arm-level and chromosome-level copy number gains suggestive of a shift in ploidy without concurrent pathogenic mutations. The results of the present study suggest that CTNNB1 mutations (likely subclonal) are only rarely present in SSCTs; instead, most of them harbor genomic alterations similar to those seen in testicular sex cord-stromal tumors with pure or predominant spindle cell components. A notable exception was a testicular SLCT with morphologic features identical to the ovarian counterpart, which harbored a DICER1 mutation.

The Clinicopathological and Molecular Characteristics of Endocervical Gastric-Type Adenocarcinoma and the Use of Claudin18.2 as a Potential Therapeutic Target

Endocervical gastric-type adenocarcinoma (GAS) is an aggressive type of endocervical mucinous adenocarcinoma characterized as being unrelated to human papillomavirus (HPV) and resistant to chemo/radiotherapy. In this study, we investigated the histology, immunohistochemistry patterns, and molecular characteristics in a large cohort of GAS (n = 62). Histologically, the majority of GAS cases exhibited a distinct morphology resembling gastric glands, although 2 exceptional cases exhibited HPV-associated adenocarcinoma morphology while retaining the characteristic histology of GAS at the invasive front. By immunohistochemistry, Claudin18.2 emerged as a highly sensitive and specific marker for GAS. Additionally, the strong expression of Claudin18.2 in patients with GAS indicated the potential of anti-Claudin18.2 therapy in the treatment of GAS. Other immunohistochemistry markers, including Muc6, p16, p53, Pax8, ER, and PR, may provide additional diagnostic clues for GAS. Quantitative methylation analysis revealed that the overexpression of Claudin18.2 in GAS was governed by the hypomethylation of the CLDN18.2 promoter CpG islands. To further elucidate the pathogenic mechanisms of GAS and its relationship with gastric adenocarcinoma, we performed whole exome sequencing on 11 GAS and 9 gastric adenocarcinomas. TP53, CDKN2A, STK11, and TTN emerged as the most frequently mutated genes in GAS. Mutations in these genes primarily affected cell growth, cell cycle regulation, senescence, and apoptosis. Intriguingly, these top mutated genes in GAS were also commonly mutated in gastric and pancreaticobiliary adenocarcinomas. Regarding germline variants, we identified a probably pathogenic variant in SPINK1, a gene linked to hereditary pancreatic cancer syndrome, in one GAS sample. This finding suggests a potential pathogenic link between pancreatic cancers and GAS. Overall, GAS exhibits molecular characteristics that resemble those observed in gastric and pancreaticobiliary adenocarcinomas, thereby lending support to the aggressive nature of GAS compared with HPV-associated adenocarcinoma.

PLAG1-Rearranged Uterine Sarcomas: A Study of 11 Cases Showing a Wide Phenotypical Spectrum Not Limited to Myxoid Leiomyosarcoma-Like Morphology

PLAG1 gene fusions were recently identified in a subset of uterine myxoid leiomyosarcomas (M-LMS). However, we have encountered cases of PLAG1-rearranged uterine sarcomas lacking M-LMS-like morphology and/or any expression of smooth muscle markers. To better characterize their clinicopathologic features, we performed a multiinstitutional search that yielded 11 cases. The patients ranged in age from 34 to 72 years (mean, 57 years). All tumors arose in the uterine corpus, ranging in size from 6.5 to 32 cm (mean, 15 cm). The most common stage at presentation was pT1b (n = 6), and 3 cases had stage pT1 (unspecified), and 1 case each presented in stages pT2a and pT3b. Most were treated only with hysterectomy and adnexectomy. The follow-up (range, 7-71 months; median, 39 months) was available for 7 patients. Three cases (7-21 months of follow-up) had no evidence of disease. Three of the 4 remaining patients died of disease within 55 to 71 months, while peritoneal spread developed in the last patient, and the patient was transferred for palliative care at 39 months. Morphologically, the tumors showed a high intertumoral and intratumoral heterogeneity. M-LMS-like and epithelioid leiomyosarcoma-like morphology were present in 3 and 5 primary tumors, respectively, the remaining mostly presented as nondescript ovoid or spindle cell sarcomas. Unusual morphologic findings included prominently hyalinized stroma (n = 3), adipocytic differentiation with areas mimicking myxoid liposarcoma (n = 2), osteosarcomatous differentiation (n = 1), and undifferentiated pleomorphic sarcoma-like areas (n = 1). The mitotic activity ranged from 3 to 24 mitoses per 10 high-power fields (mean, 9); 3 of 10 cases showed necrosis. In 3 of 11 cases, no expression of smooth muscle actin, h-caldesmon, or desmin was noted, whereas 5 of 5 cases expressed PLAG1. By RNA sequencing, the following fusion partners were identified: PUM1, CHCHD7 (each n = 2), C15orf29, CD44, MYOCD, FRMD6, PTK2, and TRPS1 (each n = 1). One case only showed PLAG1 gene break by fluorescence in situ hybridization. Our study documents a much broader morphologic spectrum of PLAG1-rearranged uterine sarcomas than previously reported, encompassing but not limited to M-LMS-like morphology with occasional heterologous (particularly adipocytic) differentiation. As it is currently difficult to precisely define their line of differentiation, for the time being, we suggest using a descriptive name "PLAG1-rearranged uterine sarcoma."

Methylation profiles of imprinted genes are distinct between mature ovarian teratoma, complete hydatidiform mole, and extragonadal mature teratoma

Mature ovarian teratoma is considered to be a parthenogenetic tumor that arises from a single oocyte/ovum. Conversely, complete hydatidiform mole (CHM) is androgenetic in origin: classic CHM arises from a single or two sperm. Since mature ovarian teratoma and CHM have only maternal and paternal genomes, respectively, their genome imprinting is theoretically reverse, but this has yet to be investigated. Genome imprinting in struma ovarii, a special form of mature teratoma, remains unclear. Although a mature teratoma can rarely arise in extragonadal sites, its genome imprinting, as well as cell origin, is poorly understood. One of the most important mechanisms of genome imprinting is DNA methylation. To investigate the methylation profile of imprinted genes, we performed methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) of 21 imprinting control region (ICRs) of 9 imprinted genes/gene clusters in formalin-fixed, paraffin-embedded samples obtained from 12 mature ovarian teratomas, 6 struma ovarii, 10 CHMs, and 7 extragonadal (1 sacrococcygeal, 6 mediastinal) mature teratomas of females. In mature ovarian teratomas, ICRs of maternally and paternally imprinted genes showed high and low levels of methylation, respectively, and this pattern was almost reverse in CHMs. In CHMs, however, some ICRs showed aberrant methylation. The methylation profile of struma ovarii was comparable to that of mature ovarian teratomas, except for an adenomatous tumor. In extragonadal mature teratomas, the methylation pattern was somatic or irregular. In conclusion, mature ovarian teratomas/struma ovarii, CHMs, and extragonadal mature teratomas showed distinct methylation profiles of imprinted genes. Ovarian teratomas and CHMs are most likely to inherit their methylation profiles from their ancestral germ cells, although some aberrant methylation suggests a relaxation of imprinting in CHMs and a subset of struma ovarii. Extragonadal mature teratomas may carry a methylation profile of misplaced primordial germ cells or possibly somatic cells that have been reprogrammed in vivo.

Cyclin D1 Overexpression Predicts Poor Disease-Specific Survival in Human Papillomavirus-Independent Vulvar Squamous Cell Carcinoma

The amplification of CCND1 is associated with the development and progression of various cancers. In a recent study, we showed that almost all adverse outcomes in vulvar squamous cell carcinomas (VSCC) occurred in patients with human papillomavirus (HPV)-independent, TP53-mutated tumors harboring CCND1 gains. In this study, we analyzed the association between CCND1 gain, cyclin D1 immunohistochemistry (IHC), and disease-specific survival (DSS) in a series of patients with HPV-independent VSCC. All patients who underwent primary surgery for VSCC at the Hospital Clínic of Barcelona, Spain, from 1975 to 2023 were recruited ("overall" cohort, n = 139). IHC for p53 and cyclin D1 was performed in all cases. In a subset of patients, we performed DNA sequencing to evaluate CCND1 copy number variations ("sequencing" cohort, n = 54). Cyclin D1 IHC overexpression (≥50% of tumor cells) had 94% sensitivity and 67% specificity as a surrogate marker of CCND1 gain. In the "sequencing" cohort, only CCND1 gains were significantly associated with impaired DSS in the multivariate analysis (hazard ratio [HR], 4.15; 95% CI, 1.08-5.40; P = .032), whereas stage or mutant TP53 status did not reach statistical significance. In the "overall" cohort, advanced stage (HR, 2.41; 95% CI, 1.08-5.39; P = .032) and cyclin D1 IHC overexpression (HR, 4.89; 95% CI, 1.77-18.5; P = .001) were associated with worse DSS in the multivariate analysis, whereas abnormal p53 IHC was not (HR, 5.06; 95% CI, 0.68-647; P = .138). In conclusion, cyclin D1 overexpression is an acceptable surrogate for CCND1 gain and has a much stronger adverse prognostic impact than altered p53 IHC in patients with HPV-independent VSCC.

Assessment of Efficacy and Accuracy of Cervical Cytology Screening With Artificial Intelligence Assistive System

The role of artificial intelligence (AI) in pathology offers many exciting new possibilities for improving patient care. This study contributes to this development by identifying the viability of the AICyte assistive system for cervical screening, and investigating the utility of the system in assisting with workflow and diagnostic capability. In this study, a novel scanner was developed using a Ruiqian WSI-2400, trademarked AICyte assistive system, to create an AI-generated gallery of the most diagnostically relevant images, objects of interest (OOI), and provide categorical assessment, according to Bethesda category, for cervical ThinPrep Pap slides. For validation purposes, 2 pathologists reviewed OOIs from 32,451 cases of ThinPrep Paps independently, and their interpretations were correlated with the original ThinPrep interpretations (OTPI). The analysis was focused on the comparison of reporting rates, correlation between cytological results and histologic follow-up findings, and the assessment of independent AICyte screening utility. Pathologists using the AICyte system had a mean reading time of 55.14 seconds for the first 3000 cases trending down to 12.90 seconds in the last 6000 cases. Overall average reading time was 22.23 seconds per case compared with a manual reading time approximation of 180 seconds. Usage of AICyte compared with OTPI had similar sensitivity (97.89% vs 97.89%) and a statistically significant increase in specificity (16.19% vs 6.77%) for the detection of cervical intraepithelial neoplsia 2 and above lesions. When AICyte was run alone at a 50% negative cutoff value, it was able to read slides with a sensitivity of 99.30% and a specificity of 9.87%. When AICyte was run independently at this cutoff value, no sole case of high-grade squamous intraepithelial lesions/squamous cell carcinoma squamous lesion was missed. AICyte can provide a potential tool to help pathologists in both diagnostic capability and efficiency, which remained reliable compared with the baseline standard. Also unique for AICyte is the development of a negative cutoff value for which AICyte can categorize cases as "not needed for review" to triage cases and lower pathologist workload. This is the largest case number study that pathologists reviewed OOI with an AI-assistive system. The study demonstrates that AI-assistive system can be broadly applied for cervical cancer screening.

Testicular Juvenile Granulosa Cell Tumors Demonstrate Recurrent Loss of Chromosome 10 and Absence of Molecular Alterations Described in Ovarian Counterparts

Testicular juvenile granulosa cell tumors (JGCTs) are a rare type of sex cord-stromal tumor, accounting for <5% of all neoplasms of the prepubertal testis. Previous reports have demonstrated sex chromosome anomalies in a small subset of cases, but the molecular alterations associated with JGCTs remain largely undescribed. We evaluated 18 JGCTs using massive parallel DNA and RNA sequencing panels. The median patient age was <1 month (range, newborn to 5 months). The patients presented with scrotal or intra-abdominal masses/enlargement, and all underwent radical orchiectomy (17 unilateral and 1 bilateral). The median tumor size was 1.8 cm (range, 1.3-10.5 cm). Histologically, the tumors were purely cystic/follicular or mixed (ie, solid and cystic/follicular). All cases were predominantly epithelioid, with 2 exhibiting prominent spindle cell components. Nuclear atypia was mild or absent, and the median number of mitoses was 0.4/mm

PTEN Deficiency in Tubo-Ovarian High-Grade Serous Carcinoma is Associated with Poor Progression-Free Survival and is Mutually Exclusive with CCNE1 Amplification

As a critical tumor suppressor, PTEN has gained much attention in cancer research. Emerging evidence suggests an association between PTEN status and clinical outcome in certain tumors, and may be predictive of response to several therapies. However, the significance of PTEN deficiency in tubo-ovarian high-grade serous carcinomas (HGSCs) is still poorly understood. We evaluated PTEN expression in HGSCs and determined its clinical relevance. A cohort of 76 HGSC specimens was profiled using tissue microarray. Immunohistochemistry (IHC) of PTEN, ER, PR, AR, CD8, FOXP3, and PD-L1 was performed. Targeted gene panel testing by massively parallel sequencing was performed in 51 cases. PTEN deficiency (complete or subclonal loss) detected by IHC was identified in 13 of the 62 HGSCs (21%) and was significantly correlated with reduced expression of ER and worse first progression-free survival (P < .05) but not with PD-L1 expression, the density of intratumoral T lymphocytes, or overall survival. In our cohort, tumor progression within 1 year of PARP inhibitor therapy was found more frequently in PTEN-deficient cases than in PTEN-intact cases (100% vs 52%). Molecular profiling showed that intragenic mutation or deletion was not the predominant mechanism for PTEN inactivation in HGSCs. In addition, CCNE1 amplification was found to be mutually exclusive with PTEN deficiency at both protein and DNA levels. An analysis of the genomic data from 1702 HGSC samples deposited with The Cancer Genome Atlas database obtained from cBioPortal confirmed the low rate of detection of PTEN gene alterations and the mutually exclusive nature of PTEN loss and CCNE1 amplification in HGSCs. These findings indicate that PTEN deficiency defines a distinct clinically significant subgroup of HGSCs with a tendency for ER negativity, wild-type CCNE1 status, inferior clinical outcomes, and potential drug resistance. These tumors may benefit from PI3K pathway inhibitors in combination with other ovarian cancer regimens, which deserves further investigation.

Opening the Black Box: Spatial Transcriptomics and the Relevance of Artificial Intelligence–Detected Prognostic Regions in High-Grade Serous Carcinoma

Image-based deep learning models are used to extract new information from standard hematoxylin and eosin pathology slides; however, biological interpretation of the features detected by artificial intelligence (AI) remains a challenge. High-grade serous carcinoma of the ovary (HGSC) is characterized by aggressive behavior and chemotherapy resistance, but also exhibits striking variability in outcome. Our understanding of this disease is limited, partly due to considerable tumor heterogeneity. We previously trained an AI model to identify HGSC tumor regions that are highly associated with outcome status but are indistinguishable by conventional morphologic methods. Here, we applied spatially resolved transcriptomics to further profile the AI-identified tumor regions in 16 patients (8 per outcome group) and identify molecular features related to disease outcome in patients who underwent primary debulking surgery and platinum-based chemotherapy. We examined formalin-fixed paraffin-embedded tissue from (1) regions identified by the AI model as highly associated with short or extended chemotherapy response, and (2) background tumor regions (not identified by the AI model as highly associated with outcome status) from the same tumors. We show that the transcriptomic profiles of AI-identified regions are more distinct than background regions from the same tumors, are superior in predicting outcome, and differ in several pathways including those associated with chemoresistance in HGSC. Further, we find that poor outcome and good outcome regions are enriched by different tumor subpopulations, suggesting distinctive interaction patterns. In summary, our work presents proof of concept that AI-guided spatial transcriptomic analysis improves recognition of biologic features relevant to patient outcomes.

POLE-Mutated Uterine Carcinosarcomas: A Clinicopathologic and Molecular Study of 11 Cases

Uterine carcinosarcomas (UCS) are high-grade biphasic neoplasms with generally poor outcomes. Based on The Cancer Genome Atlas molecular classification of endometrial carcinomas, the majority of UCS are classified as copy-number high/serous-like (p53-abnormal); however, a small subset represent other molecular subtypes, including those that harbor POLE mutations. We identified 11 POLE-mutated (POLEmut) UCS across 3 institutions and assessed the clinical, histopathologic, immunohistochemical, and molecular features of these tumors. POLEmut UCS occurred in adult women (median age, 64 years; range, 48-79 years) and usually presented as The International Federation of Gynecology and Obstetrics 2009 clinical stage IA (n = 4) or IB (n = 3). Almost all tumors were predominantly carcinomatous (n = 10), with most showing endometrioid morphology (n = 7), followed by ambiguous (n = 4) and serous (n = 3) histotypes. By immunohistochemistry, 7 tumors showed aberrant or subclonally aberrant expression of p53, 6 of which harbored pathogenic mutations in TP53 by sequencing. Other frequent mutations included PIK3CA (10/11), PTEN (8/11), RB1 (7/11), ARID1A (7/11), ATM (6/11), PIK3RA (5/11), and FBXW7 (4/11). Two tumors demonstrated loss of mismatch repair protein expression, and 1 had subclonal loss. Heterologous differentiation was uncommon, and only chondrosarcomatous type (n = 2) was observed. Mean and median follow-ups were 24.3 and 14.1 months, respectively (range, 1.4-61.1 months). Ten patients (91%) had no recurrences or death from disease, although 3 of these had follow-up periods <1 year. One patient, with the subclonal POLE variant, presented with stage IV disease and died 1.4 months after surgery. In conclusion, POLEmut UCS demonstrate unique morphologic and immunohistochemical features compared with their p53-abnormal counterparts and may have significant prognostic differences. Our study supports full molecular classification of UCS. We also raise awareness for potentially assessing POLE mutation allele frequency and clonality in consideration of classifying a tumor as POLEmut.

The MEF2D::NCOA2 Fusion Defines a Distinct Emerging Vulvovaginal Myxoid Epithelioid Tumor With Smooth Muscle Differentiation

Myocyte-specific enhancer factor 2D gene and nuclear receptor coactivator 2 gene fusion (MEF2D::NCOA2) was recently reported in 2 vulvovaginal myxoid epithelioid smooth muscle tumors. We aimed to perform an integrated approach combining clinical, morphologic, immunohistochemical, and molecular profiling analyses, including targeted RNA sequencing, targeted gene expression analysis profiling with clustering, DNA mutational analysis, and array comparative genomic hybridization in a series of 3 MEF2D::NCOA2 fusion-associated vulvovaginal tumors, to better describe this entity. The median age at diagnosis was 45 years. Tumors were well circumscribed and located deeply within the vulva, vaginal wall, or between the bladder and the vagina (1/3, 33.3% each). The median size of tumors was 2.5 cm. All tumors had a similar morphology, reminiscent of smooth muscle tumor with prominent myxoid stromal changes (3/3, 100%). Tumor cells were haphazardly arranged in short fascicles and were mostly spindle cells. Microcystic spaces lined by epithelioid cells and/or sheets of epithelioid cells were observed in all tumors (3/3, 100%), associated with a myxoid background. Cytologic atypia was none to mild, and the mitotic counts were always low (≤1 mitosis/high-power fields). Immunohistochemistry found smooth muscle actin, desmin, h-caldesmon, estrogen receptors, and CD34 to be intensely and diffusely expressed in all tumors (3/3, 100%). A MEF2D::NCOA2 transcript was observed in all tumors (3/3, 100%), which was the driver of molecular alteration. No pathogenic variants were found, and array comparative genomic hybridization found simple genomic profiles for all tumors (3/3, 100%). On targeted gene expression analysis, MEF2D::NCOA2 fusion-associated tumors clustered distinctly from other gynecologic mimickers and neoplasms with myxoid stromal changes (vulvovaginal leiomyomas, myxoid vulvovaginal leiomyomas, deep angiomyxomas, myxoid leiomyosarcomas, myxoid endometrial stromal sarcomas, and inflammatory myofibroblastic tumors). The signaling pathways involved in this entity included the expression of genes encoding smooth muscle phenotype proteins, favoring a smooth muscle (myoid) differentiation. All patients were alive and free of disease at the last follow-up. To conclude, vulvovaginal MEF2D::NCOA2 fusion-associated tumors are distinct and emerging entities, with a rather indolent behavior.

Predicting Lymph Node Metastasis From Primary Cervical Squamous Cell Carcinoma Based on Deep Learning in Histopathologic Images

We developed a deep learning framework to accurately predict the lymph node status of patients with cervical cancer based on hematoxylin and eosin-stained pathological sections of the primary tumor. In total, 1524 hematoxylin and eosin-stained whole slide images (WSIs) of primary cervical tumors from 564 patients were used in this retrospective, proof-of-concept study. Primary tumor sections (1161 WSIs) were obtained from 405 patients who underwent radical cervical cancer surgery at the Fudan University Shanghai Cancer Center (FUSCC) between 2008 and 2014; 165 and 240 patients were negative and positive for lymph node metastasis, respectively (including 166 with positive pelvic lymph nodes alone and 74 with positive pelvic and para-aortic lymph nodes). We constructed and trained a multi-instance deep convolutional neural network based on a multiscale attention mechanism, in which an internal independent test set (100 patients, 228 WSIs) from the FUSCC cohort and an external independent test set (159 patients, 363 WSIs) from the Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma cohort of the Cancer Genome Atlas program database were used to evaluate the predictive performance of the network. In predicting the occurrence of lymph node metastasis, our network achieved areas under the receiver operating characteristic curve of 0.87 in the cross-validation set, 0.84 in the internal independent test set of the FUSCC cohort, and 0.75 in the external test set of the Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma cohort of the Cancer Genome Atlas program. For patients with positive pelvic lymph node metastases, we retrained the network to predict whether they also had para-aortic lymph node metastases. Our network achieved areas under the receiver operating characteristic curve of 0.91 in the cross-validation set and 0.88 in the test set of the FUSCC cohort. Deep learning analysis based on pathological images of primary foci is very likely to provide new ideas for preoperatively assessing cervical cancer lymph node status; its true value must be validated with cervical biopsy specimens and large multicenter datasets.

Clonal relationship and directionality of progression of synchronous endometrial and ovarian carcinomas in patients with DNA mismatch repair-deficiency associated syndromes

Sporadic synchronous endometrial (ECs) and ovarian cancers (OCs), although clinically considered to be independent primaries, have been shown to be clonally related and likely constitute metastases from each other. We sought to define whether synchronous ECs/OCs in patients with DNA mismatch repair (MMR)-deficiency syndromes would be clonally related. We subjected synchronous ECs/OCs from four patients (LS3-LS6) with clinically confirmed Lynch syndrome (LS) and one patient with constitutional mismatch repair-deficiency syndrome (CMMRD) to massively parallel sequencing targeting 468 cancer-related genes. Somatic mutations, copy number alterations (CNAs), clonal relatedness and clonal decomposition analyses were performed using previously described bioinformatics methods. All synchronous ECs/OCs analyzed were considered independent primaries based on clinicopathologic criteria. Sequencing analysis revealed that the ECs/OCs of three cases (LS2-CMMRD, L3, L4) harbored similar repertoires of somatic mutations and CNAs and were clonally related. In these three cases, a subset of subclonal mutations in the EC became clonal in the OC, suggesting that the EC was likely the substrate from which the OC developed. LS5's EC/OC had distinct mutational profiles but shared specific CNAs. In contrast, LS6's EC/OC harbored distinct somatic mutations and lacked CNAs, consistent with each tumor constituting an independent primary lesion. In LS5 and LS6, PTEN mutations and PTEN loss of protein expression were found to be restricted to the EC. Finally, re-analysis of sequencing data of sporadic synchronous ECs/OCs supported the observations made in the current study that the directionality of progression is likely from the endometrium to the ovary. In conclusion, contrary to sporadic synchronous ECs/OCs, which are almost invariably clonally related, ECs/OCs simultaneously involving the uterus and ovary in LS patients may represent distinct primary tumors. A subset of MMR-deficiency syndrome-related synchronous ECs/OCs, however, may originate from a single primary tumor at variance with their clinical diagnosis, with the endometrium being the likeliest site of origin.

Characterization of TP53-wildtype tubo-ovarian high-grade serous carcinomas: rare exceptions to the binary classification of ovarian serous carcinoma

While TP53 mutation is widely considered to be a defining feature of tubo-ovarian high-grade serous carcinoma (HGSC), rare TP53-mutation-negative cases have been reported. To gain further insight into this rare subset, a retrospective review was conducted on 25 TP53-wildtype tubo-ovarian HGSCs, constituting 2.5% of 987 HGSCs profiled by the MSK-IMPACT sequencing platform. Consistent with serous differentiation, positive staining for Pax8 and WT1 was present in virtually all TP53-wildtype HGSCs. Other characteristic features of HGSC, such as serous tubal intraepithelial carcinoma, or genetic alterations of CCNE1 and BRCA1/2 were identified in these tumors, furthering supporting their classification as bona fide HGSC, despite lacking TP53 mutations. Overall, the level of chromosomal instability of TP53-wildtype HGSCs was intermediate between low-grade serous carcinoma (LGSC) and TP53-mutated HGSC. Morphologic assessment by observers blinded to mutation status revealed a significant subset of tumors with Grade 2 nuclear atypia (which exceeds the degree of atypia allowed for LGSC, but less than typically encountered for HGSC) combined with micropapillary features (6/19, 32%, chemotherapy-naive TP53-wildtype HGSCs compared to 0/21, 0%, TP53-mutated HGSCs; p = 0.007). Some TP53-wildtype HGSCs harbored driver mutations in KRAS (n = 3), BRAF (n = 1) or NRAS (n = 2). Overall, 10 (40%) cases had "LGSC-like" morphology (i.e., Grade 2 nuclear atypia and micropapillary features) and/or RAS/RAF mutation, and most of these showed a wildtype p53 pattern of expression by immunohistochemistry (7/9, 78%). The remaining TP53-wildtype HGSCs (n = 15, 60%) exhibited severe nuclear atypia (Grade 3) and were morphologically indistinguishable from conventional TP53-mutated HGSC. Despite lacking genetic alterations of TP53, these "usual HGSC-like" tumors often showed evidence of p53 dysfunction, including downregulation of expression ('null' or equivocal p53 staining in 9/14, 64%) or MDM2 amplification (n = 2). Our results support the existence of TP53-wildtype HGSCs, which comprise a heterogeneous group of tumors which may arise via distinct pathogenic mechanisms.

Refined cut-off for TP53 immunohistochemistry improves prediction of TP53 mutation status in ovarian mucinous tumors: implications for outcome analyses

TP53 mutations are implicated in the progression of mucinous borderline tumors (MBOT) to mucinous ovarian carcinomas (MOC). Optimized immunohistochemistry (IHC) for TP53 has been established as a proxy for the TP53 mutation status in other ovarian tumor types. We aimed to confirm the ability of TP53 IHC to predict TP53 mutation status in ovarian mucinous tumors and to evaluate the association of TP53 mutation status with survival among patients with MBOT and MOC. Tumor tissue from an initial cohort of 113 women with MBOT/MOC was stained with optimized IHC for TP53 using tissue microarrays (75.2%) or full sections (24.8%) and interpreted using established criteria as normal or abnormal (overexpression, complete absence, or cytoplasmic). Cases were considered concordant if abnormal IHC staining predicted deleterious TP53 mutations. Discordant tissue microarray cases were re-evaluated on full sections and interpretational criteria were refined. The initial cohort was expanded to a total of 165 MBOT and 424 MOC for the examination of the association of survival with TP53 mutation status, assessed either by TP53 IHC and/or sequencing. Initially, 82/113 (72.6%) cases were concordant using the established criteria. Refined criteria for overexpression to account for intratumoral heterogeneity and terminal differentiation improved concordance to 93.8% (106/113). In the expanded cohort, 19.4% (32/165) of MBOT showed evidence for TP53 mutation and this was associated with a higher risk of recurrence, disease-specific death, and all-cause mortality (overall survival: HR = 4.6, 95% CI 1.5-14.3, p = 0.0087). Within MOC, 61.1% (259/424) harbored a TP53 mutation, but this was not associated with survival (overall survival, p = 0.77). TP53 IHC is an accurate proxy for TP53 mutation status with refined interpretation criteria accounting for intratumoral heterogeneity and terminal differentiation in ovarian mucinous tumors. TP53 mutation status is an important biomarker to identify MBOT with a higher risk of mortality.

Comprehensive genomic profiling reveals ubiquitous KRAS mutations and frequent PIK3CA mutations in ovarian seromucinous borderline tumor

The molecular underpinnings of seromucinous borderline tumor (SMBT) - an uncommon ovarian epithelial neoplasm characterized by association with endometriosis, frequent bilateral ovarian involvement, and occasional progression to invasive carcinoma - remain poorly understood. Here, we sought to comprehensively characterize the mutational landscape of SMBT and elucidate the clonal relationship between bilateral ovarian SMBTs. We also compared the mutational profiles between SMBTs and concurrent invasive carcinomas. Formalin-fixed, paraffin-embedded tissue specimens were retrieved from 28 patients diagnosed with SMBT. Massively parallel sequencing of 409 cancer-related genes was conducted to identify somatic mutations in 33 SMBT samples and four concurrent invasive carcinoma specimens. TERT promoter mutations were assessed by Sanger sequencing, whereas immunohistochemistry was used as a surrogate tool for detecting deletions or epigenetic silencing of relevant tumor suppressor genes. Twenty-six (92.9%) of the 28 patients were diagnosed with stage I SMBTs. Seven (25%) cases showed bilateral ovarian involvement and 13 (46%) had concomitant endometriosis. Concurrent ovarian carcinomas were identified in three patients, whereas one case had a synchronous endometrial carcinoma. Somatic mutations in the KRAS, PIK3CA, and ARID1A genes were identified in 100, 60.7, and 14.3% of SMBT samples, respectively. In contrast, TERT promoter mutations and DNA mismatch repair deficiencies were absent. Sequencing of paired specimens from patients with bilateral SMBT revealed the presence of at least two shared somatic mutations, suggestive of a clonal relationship. Similarly, we identified shared somatic mutations between SMBT samples and concurrent ovarian carcinoma specimens. Taken together, these findings demonstrated a distinct mutational landscape of SMBT in which (1) KRAS is invariably mutated, (2) PIK3CA is frequently mutated, and (3) TERT promoter mutations and DNA mismatch repair deficiencies are absent. Our findings represent the first extensive characterization of this rare ovarian neoplasm, with potential implications for disease classification and molecular diagnostics.

Low junctional adhesion molecule-A expression is associated with an epithelial to mesenchymal transition and poorer outcomes in high-grade serous carcinoma of uterine adnexa

High-grade serous carcinoma of uterine adnexa (HGSC) is the most frequent histotype of epithelial ovarian cancer and has a poor 5-year survival rate due to late-stage diagnosis and the poor efficacy of standard treatments. Novel biomarkers of cancer outcome are needed to identify new targetable pathways and improve personalized treatments. Cell-surface screening of 26 HGSC cell lines by high-throughput flow cytometry identified junctional adhesion molecule 1 (JAM-A, also known as F11R) as a potential biomarker. Using a multi-labeled immunofluorescent staining coupled with digital image analysis, protein levels of JAM-A were quantified in tissue microarrays from three HGSC patient cohorts: a discovery cohort (n = 101), the Canadian Ovarian Experimental Unified Resource cohort (COEUR, n = 1158), and the Canadian Cancer Trials Group OV16 cohort (n = 267). Low JAM-A level was associated with poorer outcome in the three cohorts by Kaplan-Meier (p = 0.023, p < 0.001, and p = 0.036, respectively) and was an independent marker of shorter survival in the COEUR cohort (HR = 0.517 (0.381-703), p < 0.001). When analyses were restricted to patients treated by taxane-platinum-based chemotherapy, low JAM-A protein expression was associated with poorer responses in the COEUR (p < 0.001) and OV16 cohorts (p = 0.006) by Kaplan-Meier. Decreased JAM-A gene expression was an indicator of poor outcome in gene expression datasets including The Cancer Genome Atlas (n = 606, p = 0.002) and Kaplan-Meier plotter (n = 1816, p = 0.024). Finally, we observed that tumors with decreased JAM-A expression exhibited an enhanced epithelial to mesenchymal transition (EMT) signature. Our results demonstrate that JAM-A expression is a robust prognostic biomarker of HGSC and may be used to discriminate tumors responsive to therapies targeting EMT.

Association of PD-L1 expression by immunohistochemistry and gene microarray with molecular subtypes of ovarian tumors

Identifying patients who respond to immune checkpoint blockade (ICB) is a significant challenge in oncology. While PD-L1 expression by immunohistochemistry (IHC) is the current diagnostic gold standard for patient selection, it nevertheless does not capture all patients who may respond to ICB. Recent gene expression studies in high-grade serous ovarian carcinoma have defined an immunoreactive molecular subtype that has a measurable difference in patient survival compared with non-immunoreactive subtypes, but no studies have yet demonstrated its impact on predicting response to ICB. As a step toward establishing the predictive value of gene expression classifiers in ICB, we assessed the relationship between PD-L1 IHC and molecular subtypes of ovarian epithelial cancer. This was done by analyzing a total of 93 tissue specimens from patients with stage III and IV disease, and comparing PD-L1 IHC with gene expression by Agilent microarrays using TCGA-defined subtypes. We showed that ovarian tumors with elevated IHC PD-L1 expression are most strongly associated with immunoreactive subtype as compared with other molecular subtypes, reaching statistical significance against differentiated (Dunn's test, 33.39, p = 0.0003) and mesenchymal (39.63, p < 0.0001) subtypes. Comparing PD-L1 scoring with CPS vs. TPS showed similar trends, but with stronger correlation strength when using CPS (Kruskal-Wallis, H = 27.52, p < 0.0001), as opposed to TPS (H = 25.04, p < 0.0001). Interestingly, while PD-L1 gene expression by microarray was significantly increased in the immunoreactive subtype (H = 20.25, p = 0.0002), it showed a positive but relatively poor correlation to IHC. Overall, the results demonstrate potential value in use of the molecular classifier to select patients for ICB, pending further studies that assess its ability to predict treatment outcomes. In the future, integration of cellular, protein, and genomic biomarkers in the tumor and tumor microenvironment may improve current methods of predicting treatment response.

Genomic profiling of primary and recurrent adult granulosa cell tumors of the ovary

Adult-type granulosa cell tumor (aGCT) is a rare malignant ovarian sex cord-stromal tumor, harboring recurrent FOXL2 c.C402G/p.C134W hotspot mutations in 97% of cases. These tumors are considered to have a favorable prognosis, however aGCTs have a tendency for local spread and late recurrences, which are associated with poor survival rates. We sought to determine the genetic alterations associated with aGCT disease progression. We subjected primary non-recurrent aGCTs (n = 7), primary aGCTs that subsequently recurred (n = 9) and their matched recurrences (n = 9), and aGCT recurrences without matched primary tumors (n = 10) to targeted massively parallel sequencing of ≥410 cancer-related genes. In addition, three primary non-recurrent aGCTs and nine aGCT recurrences were subjected to FOXL2 and TERT promoter Sanger sequencing analysis. All aGCTs harbored the FOXL2 C134W hotspot mutation. TERT promoter mutations were found to be significantly more frequent in recurrent (18/28, 64%) than primary aGCTs (5/19, 26%, p = 0.017). In addition, mutations affecting TP53, MED12, and TET2 were restricted to aGCT recurrences. Pathway annotation of altered genes demonstrated that aGCT recurrences displayed an enrichment for genetic alterations affecting cell cycle pathway-related genes. Analysis of paired primary and recurrent aGCTs revealed that TERT promoter mutations were either present in both primary tumors and matched recurrences or were restricted to the recurrence and absent in the respective primary aGCT. Clonal composition analysis of these paired samples further revealed that aGCTs display intra-tumor genetic heterogeneity and harbor multiple clones at diagnosis and relapse. We observed that in a subset of cases, recurrences acquired additional genetic alterations not present in primary aGCTs, including TERT, MED12, and TP53 mutations and CDKN2A/B homozygous deletions. Albeit harboring relatively simple genomes, our data provide evidence to suggest that aGCTs are genetically heterogeneous tumors and that TERT promoter mutations and/or genetic alterations affecting other cell cycle-related genes may be associated with disease progression and recurrences.

Two types of primary mucinous ovarian tumors can be distinguished based on their origin

The origin of primary mucinous ovarian tumors is unknown. We explore the hypothesis that they originate from either Brenner tumors or teratomas and examine differences between the tumors that arise in these settings. A total of 104 Brenner tumor-associated mucinous tumors and 58 teratoma-associated mucinous tumors were analyzed. Immunohistochemistry for 21 antigens and fluorescence in situ hybridization for ERBB2 and MYC were performed. Genome-wide copy number analysis and mutation analysis for 56 cancer-related genes was carried out on a subset of mucinous ovarian tumors and their complementary Brenner tumor or teratoma. Patients with teratoma-associated mucinous tumors were significantly younger than patients with Brenner tumor-associated mucinous tumors (43 vs. 61 years). During progression from cystadenoma to atypical proliferative mucinous (borderline) tumor to carcinoma expression of typical gastrointestinal markers was increased in both Brenner tumor-associated and teratoma-associated mucinous tumors. Brenner tumor-associated mucinous tumors showed more frequently calcifications and Walthard cell nests, rarely expressed SATB2 and showed more often co-deletion of CDKN2A and MTAP. Teratoma-associated mucinous tumors were characterized by mucinous stromal dissection, SATB2 expression and RNF43 mutations. Other frequent mutations in both Brenner tumor-associated and teratoma-associated mucinous tumors were TP53 and KRAS mutations. Based on identical mutations or copy number profiles clonal relationships were indicated in two mucinous tumors and their associated Brenner tumor. Teratomas and Brenner tumors give rise to different subtypes of mucinous ovarian tumors. Subsequent progression pathways are comparable since both Brenner tumor-associated and teratoma-associated mucinous tumors develop a gastrointestinal immunophenotype during progression and show early mutations in KRAS and TP53. Teratoma-associated mucinous tumors may more closely resemble true gastrointestinal tumors, indicated by their expression of SATB2 and the presence of RNF43 mutations.

DNA Methylation Profiling Classifies and Reveals Origin of Gynecologic Central Nervous System-Like Tumors

Gynecologic neuroectodermal tumors either exhibit central nervous system (CNS) differentiation (CNS-like) or represent Ewing sarcoma (EWS), which lacks CNS features and harbors FET-ETS gene fusions. DNA methylation profiling reclassified CNS primitive neuroectodermal tumors into common CNS neoplasms or embryonal tumors with specific epigenetic/genetic characteristics. Its utility in classifying gynecologic neuroectodermal tumors is unknown. Whole-genome DNA methylation profiling was performed on 26 gynecologic neuroectodermal tumors (22 CNS-like tumors, 4 EWS) arising in the ovary, paratubal soft tissue, uterus, and vulva, which were classified by using sarcoma and CNS tumor DNA methylation classifiers. Sarcoma-related gene fusions were confirmed by fluorescence in situ hybridization or targeted RNA next-generation sequencing. Tumor-only whole-exome sequencing (WES) was performed in 13 cases. Copy number alterations and zygosity were inferred from DNA methylation array and WES data. Methylation abnormalities associated with imprinting were examined. The sarcoma methylation classifier identified EWS (n = 3) and high-grade endometrial stromal sarcoma (n = 1), confirmed by fluorescence in situ hybridization or next-generation sequencing detection of EWSR1 and YWHAE rearrangements, respectively. The remaining CNS-like tumors were classified by DNA methylation with positive/valid (n = 4), indeterminate (n = 9), and negative (n = 9) scores at the family level. Methylation subclasses included teratoma; embryonal tumor with multilayered rosettes, atypical; medulloblastoma, SHH-activated, subtype 3; medulloblastoma, group 3; intraocular medulloepithelioma; supratentorial ependymoma, ZFTA::RELA fused, subclass A; and diffuse pediatric-type high-grade glioma, MYCN subtype. Male biological sex was predicted in 54% of methylation-confirmed CNS-like tumors and none of the sarcomas. Among CNS-like tumors, copy number analyses identified genome-wide chromosomal gains and losses, and WES revealed genome-wide allelic imbalance suggestive of genome-wide duplications. Epigenetic imprinting analyses showed increased paternal or maternal imprinting signal across multiple chromosomes, suggesting uniparental duplication. DNA methylation profiling successfully classified gynecologic neuroectodermal tumors as known CNS tumors or sarcoma entities. Epigenetic and exomic studies indicate a male genome and increased maternal allelic contribution in CNS-like tumors, suggesting development via conception or chimerism.

Primary Vulvar and Vaginal Adenocarcinomas of Intestinal Type Are Closer To Colorectal Adenocarcinomas Than To Carcinomas of Müllerian Origin

Primary vulvar and vaginal adenocarcinomas of intestinal type (VVAIts) are very rare tumors, displaying morphologic and immunohistochemical overlap with colorectal adenocarcinomas. However, their immunoprofile and genomics are poorly studied, and their origin is still debated. Here, we studied a series of 8 VVAIts (4 vulvar and 4 vaginal) using a large panel of immunohistochemistry and DNA and RNA sequencing with clustering analyses. All tumors shared a similar morphology with colorectal adenocarcinomas and diffuse CK20 and CDX2 expression. SATB2 diffuse positivity was observed in 62.5% of tumors and CK7 in 82.5%, whereas PAX8, SOX17, p16, and estrogen and progesterone receptors were always negative. A p53 mutated-type expression was observed in 75% of tumors. All tumors were mismatch repair proficient. Neither human papillomavirus DNA nor pathogenic transcript fusions were detected. The most frequent molecular alterations were TP53 and KRAS variants in 71.4% and 42.9%, respectively. The transcriptomic analysis highlighted a robust VVAIts cluster distinct from endocervical, ovarian, lung, thyroid, salivary glands, breast, and renal carcinomas but failed to differentiate vulvar from vaginal intestinal-type tumors. On 2 different clustering analyses, VVAIts clustered altogether, very close to colorectal adenocarcinomas. Compared with endocervical adenocarcinomas of intestinal type, VVAIts had a significantly lower expression of SOX17 and epithelial-mesenchymal transition genes and a higher mitogen-activated protein kinase pathway gene expression. These results suggest that Müllerian structures leading to cervical adenocarcinomas may undergo intestinal-type transdifferentiation via an epithelial-mesenchymal transition phenomenon. Conversely, mitogen-activated protein kinase pathway activation in VVAIts, which plays a major role in colorectal adenocarcinomas, may indicate a close relationship in the carcinogenesis of these tumors. Our results indicate that adenocarcinomas of intestinal type, in the distal vagina or vestibular vulva, might be a unique and single entity, probably originating from cloacogenic embryonic remnants and/or ectopic colorectal mucosae inclusions. An open question would be to explore the efficacy of systemic drugs prescribed in colorectal cancers, in VVAIts.

International Feasibility of Applying Diagnostic Essential Criteria of the Fifth Edition World Health Organization Classification of Female Genital Tumors: Evidence for a Global Gap in Health Care Equity

The new categories of diagnostic essential criteria and desirable criteria in the fifth edition World Health Organization Classification of Female Genital Tumors (fifth WHO FGT) aim to standardize the classification of gynecologic tumors worldwide. As some essential criteria require biomarkers (immunohistochemistry [IHC] or molecular tests), we hypothesized that the applicability of the fifth WHO FGT criteria may be limited by access to these tests due to local resource constraints. After defining the essential biomarkers in the fifth WHO FGT, we conducted an international survey of pathologists to determine accessibility to essential biomarkers and then evaluated access as a function of the pathologist's country income category. A total of 37 IHC and 6 molecular tests are considered essential for diagnosing a spectrum of common and less common tumors. Among 480 respondents from 76 countries, access to the printed or online version of the fifth WHO FGT was associated with country income (P < .0001); 62.5% of low-income country respondents reported no access to either version. Routine access to IHC in general and routine access to each of the essential IHC were significantly associated with the country income category (P < .0001). Only 12.5% of low-income country respondents reported routine access to IHC in general, and none reported routine access to any essential molecular tests. Short tandem repeat genotype testing for molar pregnancy diagnosis was the least accessible essential molecular test worldwide, available to only 26.6% of the respondents, most of whom were in high-income countries. Additional essential criteria for some tumors consisted of one of 18 different specific types of tumor differentiation for which no morphologic definition was provided; high-income country respondents were more likely to routinely use IHC in these settings than lower-income country respondents (P < .0001). Conversely, the patient bore the direct responsibility for paying for IHC when used in lower-income countries compared with high-income countries (P < .0001). This survey demonstrates a global gap in health care equity due, in part, to limited access to biomarkers deemed as essential for diagnosis by the fifth WHO FGT and to the lack of diagnostic criteria adaptable to resource-limited environments. Based on the survey results, we offer several practical strategies for narrowing this gap in future editions of the WHO FGT, chief among them being a move toward resource-stratified diagnostic criteria.

Cervical carcinomas with serous-like papillary and micropapillary components: illustrating the heterogeneity of primary cervical carcinomas

Recent changes in the classification of cervical adenocarcinomas have re-categorized serous carcinoma as potentially nonexistent. However, clinical and pathological profiles of cervical adenocarcinomas with serous-like morphological features have not been systematically evaluated using the latest taxonomy and biomarkers. We studied 14 cases of primary cervical carcinomas with serous-like morphologies (papillary and micropapillary patterns). None of these cases exhibited evidence of serous carcinoma involving the upper tracts. Patient ages ranged between 34 and 86 years, most presented with abnormal uterine bleeding. Histologically, ten cases were classified as human papillomavirus (HPV)-associated carcinomas (eight usual-type endocervical adenocarcinomas and two adenosquamous carcinomas), of which six exhibited a papillary pattern and four had a micropapillary pattern. The four remaining cases were HPV-independent gastric-type adenocarcinomas, which displayed a papillary pattern in one case and a micropapillary pattern in three others. All ten HPV-associated carcinomas displayed block positive p16 and wild-type p53 by immunohistochemistry, with nine of them confirmed by HPV testing. Two of the four gastric-type adenocarcinomas had mutation-type p53, one of which also being p16 block positive. HER2 overexpression was demonstrated in 3/14 (21.4%) cases (2 HPV-associated and 1 HPV-independent). PD-L1 expression was identified in 4/10 (40%) cases, all HPV-associated. Targeted next-generation sequencing was performed in two cases with a micropapillary pattern, revealing a missense variant in ATM in an HPV-associated tumor and missense variants in TP53 and SMARCB1 in an HPV-independent tumor. The results demonstrated that primary endocervical adenocarcinomas can mimic the appearance of serous carcinoma, while not representing serous carcinoma. Serous-like papillary and micropapillary patterns may be present in both HPV-associated and HPV-independent cervical carcinomas, but none of the cases studied were unequivocally serous upon detailed analysis. Our findings support the exclusion of "cervical serous carcinoma" from existing classifications of cervical adenocarcinoma.

Prognostic Value of an Integrated Human Papillomavirus and Immunoscore Model to Predict Survival in Vulva Squamous Cell Carcinoma

Although the prognostic value of immune-related biomarkers is well characterized in many solid tumors, their significance in vulva squamous cell carcinoma (VSCC) remains unclear. In this study, we report a comprehensive analysis of programmed death ligand protein 1 (PD-L1) and immune cell infiltration in VSCC and establish immunoscore models for classification of the disease. Tissue microarrays, immunohistochemistry, and digital quantification were used to investigate the number of CD4+, CD8+, CD68+, CD14+, FoxP3+, and PD-L1+ cells in epithelial and stromal compartments of VSCC (n = 117). Immunoscores were developed using these parameters and applying the least absolute shrinkage and selection operator to identify predictors of survival. Immunoscores were then integrated with human papillomavirus (HPV) status, as determined using messenger RNA in situ hybridization, to construct internally validated nomograms. The prognostic models were subsequently applied in whole tissue sections (n = 25) to investigate agreement. Advanced VSCC (International Federation of Gynecology and Obstetrics stage III/IV) was characterized by high densities of CD68+ macrophages and PD-L1+ cells (Spearman correlation, ρ = 0.80) in the epithelium. PD-L1 status independently predicted poor progression-free survival (PFS) (hazard ratio = 1.828; 95% CI, 1.039-3.215; P = .036). Immunoscore

DNA Methylation and p53 Immunohistochemistry as Prognostic Biomarkers for Vulvar Lichen Sclerosus

Vulvar lichen sclerosus (LS) is an inflammatory dermatosis that can progress to human papillomavirus (HPV)-independent vulvar intraepithelial neoplasia (HPVi VIN) and vulvar squamous cell carcinoma (VSCC). Although LS has a much lower cancer risk compared with HPVi VIN (5% vs 50%, respectively), its incidence is significantly higher. Therefore, there is a clinical need to identify LS patients with an increased cancer risk. Our objective was to study the value of DNA methylation and p53 immunohistochemistry (IHC) as prognostic biomarkers for progression to cancer in patients with LS. Vulvar tissues from 236 patients were selected, including 75 LS and 68 HPVi VIN, both with and without cancer development, 32 VSCC, and 61 healthy vulvar controls. Samples were subjected to p53 IHC and DNA methylation analysis of a 3-gene marker panel containing ZNF582, SST, and miR124-2. Methylation levels and p53 IHC status (mutant or wild-type) were assessed and compared among all disease categories. Odds ratios were determined to identify whether the biomarkers were associated with progression to cancer in patients with LS. The highest methylation levels were found in HPVi VIN and VSCC, followed by LS and healthy vulvar controls. The largest heterogeneity in methylation levels was observed in LS cases. In fact, the 3-marker panel tested positive in 70% of LS, which progressed to VSCC vs only 17% of LS in patients without cancer development (P = .002). Also, mutant p53 IHC was observed more frequently in LS with progression to VSCC compared with nonprogressive LS cases (42% vs 3%, respectively, P = .001). Multivariable analysis identified a mutant p53 status as the only independent risk factor for cancer development in LS (odds ratio: 34.0, 95% CI: 1.4-807.4). In conclusion, DNA methylation testing and p53 IHC show strong potential as prognostic biomarkers for the identification of LS patients at high risk of progression to cancer.

Molecular assessment of testicular adult granulosa cell tumor demonstrates significant differences when compared to ovarian counterparts

Testicular adult granulosa cell tumor (AGCT) is a rare type of sex-cord stromal tumor that affects patients of a wide age range and has the potential for late metastasis. In the testis, the diagnosis of AGCTs often requires the exclusion of other more common types of sex-cord stromal tumors. Immunohistochemistry is of limited utility, being used mostly to confirm sex-cord lineage and to exclude other entities when morphology is not typical. Unlike ovarian AGCTs, which are molecularly homogeneous and harbor a specific activating FOXL2 mutation (c.7558C > T p.C134W) in >90% of cases, the molecular characteristics of testicular AGCTs remain largely unknown. In the current study, we analyzed 13 testicular AGCTs diagnosed at multiple institutions using massively parallel DNA sequencing to evaluate single nucleotide variants, copy number alterations, and structural variants. In all, 10/13 cases were sequenced successfully. Notably, the FOXL2 c.7558C > T (p.C134W) mutation was identified in only a single case (1/10, 10%). The remaining cases were molecularly heterogeneous, with largely nonrecurrent genetic variants. Putative driver events in individual cases included a well-characterized gain-of-function NRAS mutation, as well as inactivation of ATM and TP53, among others. The only highly recurrent finding was single copy loss of 22q (7/10 cases, 70%). Comparatively, the frequencies of FOXL2 c.7558C > T (p.C134W) and 22q loss in 12 metastatic ovarian AGCTs identified in our database were 92% (11/12) and 42% (5/12), respectively. The results of the present study suggest that testicular AGCTs are different from their ovarian counterparts in that they appear to be molecularly heterogeneous and only rarely harbor FOXL2 mutations.

Molecular Landscape of Mullerian Clear Cell Carcinomas Identifies The Cancer Genome Atlas-like Prognostic Subgroups

Mullerian clear cell carcinoma (CCC) is often aggressive and chemoresistant. The prognostic significance of molecular subclassification of endometrioid carcinomas is well established. However, less is known about the molecular landscape of CCC. The aim of this study was to better characterize the genetic landscape of a large cohort of CCC and correlate these findings with clinicopathologic features. CCC of the ovary (n = 72), endometrium (n = 24), and peritoneum/abdominal wall (n = 5) were retrospectively identified. Tumors had undergone tumor-only targeted sequencing using a hybrid capture next-generation sequencing panel. Median tumor mutational burden was 6.8 mutations/megabase (range, 1.3-185, 21% were ≥10 mutations/Mb). The most frequently mutated genes were ARID1A (48%), PIK3CA (45%), TP53 (23%), and PTEN (10%). ERBB2 amplification occurred in 4%. When classified according to the Cancer Genome Atlas/the Proactive Molecular Risk Classifier for Endometrial Cancer endometrial carcinoma molecular subgroups, 3 (3%) were POLE ultramutated, 5 (5%) were microsatellite instability-high (MSI-H), 20 (20%) were TP53-mutant subgroup, and 73 (72%) were no specific molecular profile (NSMP). Immunohistochemical expression of estrogen receptor, progesterone receptor, and programmed death-ligand 1 were not associated with the molecular subgroup. POLE and MSI-H tumors were characterized by an excellent prognosis, and the TP53-mutant subgroup had a worse disease-free survival than NSMP. NSMP tumors could be further substratified as high-risk NSMP if they lacked PIK3CA, PIK3R1, and ARID1A mutations, and/or harbored a TERT-promoter mutation. The Cancer Genome Atlas and NSMP-specific stratifications were prognostic for both the entire cohort and the subset of stage I ovarian tumors. On multivariable analysis, stage, lymphovascular invasion, and tumor mutational burden were prognostic for disease-free survival, whereas advanced stage and TP53-mutant subgroup - but not a TP53 mutation in isolation - were negative prognostic factors for overall survival. These data suggest that routine molecular profiling of Mullerian CCC may be warranted for both prognosis and identification of potential targeted treatments, such as immunotherapy and anti-HER2 agents.

Detection of sarcoma fusions by a next-generation sequencing based–ligation-dependent multiplex RT-PCR assay

Morphological, immunohistochemical, and molecular methods often need to be combined for accurate diagnosis and optimal clinical management of sarcomas. Here, we have developed, a new molecular diagnostic assay, for the detection of gene fusions in sarcomas. This targeted multiplexed next-generation sequencing (NGS)-based method utilizes ligation dependent reverse-transcriptase polymerase chain reaction (LD-RT-PCR-NGS) to detect oncogenic fusion transcripts involving 137 genes, leading to 139 gene fusions known to be recurrently rearranged in soft-tissue and bone tumors. 158 bone and soft-tissue tumors with previously identified fusion genes by fluorescent in situ hybridization (FISH) or RT-PCR were selected to test the specificity and the sensitivity of this assay. RNA were extracted from formalin-fixed paraffin-embedded (n = 143) or frozen (n = 15) material (specimen; n = 42 or core needle biopsies; n = 116). Tested tumors encompassed 23 major translocation-related sarcomas types, including Ewing and Ewing-like sarcomas, rhabdomyosarcomas, desmoplastic small round-cell tumors, clear-cell sarcomas, infantile fibrosarcomas, endometrial stromal sarcomas, epithelioid hemangioendotheliomas, alveolar soft-part sarcomas, biphenotypic sinonasal sarcomas, extraskeletal myxoid chondrosarcomas, myxoid/round-cell liposarcomas, dermatofibrosarcomas protuberans and solitary fibrous tumors. In-frame fusion transcripts were detected in 98.1% of cases (155/158). Gene fusion assay results correlated with conventional techniques (FISH and RT-PCR) in 155/158 tumors (98.1%). These data demonstrate that this assay is a rapid, robust, highly sensitive, and multiplexed targeted RNA sequencing assay for the detection of recurrent gene fusions on RNA extracted from routine clinical specimens of sarcomas (formalin-fixed paraffin-embedded or frozen). It facilitates the precise diagnosis and identification of tumors with potential targetable fusions. In addition, this assay can be easily customized to cover new fusions.