Kyle M. Devins

Isolated morular squamous metaplasia in endometrial biopsies and curettings: is there a role for repeated sampling?

Aims Endometrial atypical hyperplasia and low‐grade endometrioid carcinoma are often associated with morular squamous metaplasia. Limited evidence suggests that the finding of isolated morular squamous metaplasia without concomitant glandular neoplasia in biopsies is associated with a 6.5% risk of endometrial cancer in subsequent samples and warrants close follow‐up. However, its prognostic value has not been clearly determined. Methods and results The Massachusetts General Hospital pathology database was queried to identify endometrial samples with a diagnosis of ‘adenoacanthosis’, ‘morular metaplasia’, ‘squamous metaplasia’ or ‘morular squamous metaplasia’ between 2012 and 2024. Cases associated with endometrioid carcinoma, non‐atypical or atypical hyperplasia, atypical polypoid adenomyoma and gland crowding insufficient for diagnosis of atypical hyperplasia were excluded. Clinicopathologic data were collected. Outcomes were categorized as regression, persistence and progression to carcinoma. Of 32,800 endometrial samples reported during the study period, isolated morular squamous metaplasia was diagnosed in 57 (0.17%), including 42 (73.7%) biopsies and 15 (26.3%) curettings. The median patient age was 45 (21–70) years. Histologic follow‐up (at least one follow‐up sample) was available in 22 patients (median 30 months, 1–120) and included endometrial biopsy, curettage or hysterectomy. Of these 22 patients, a single follow‐up biopsy was performed in 9 (40.9%), a single curettage in 1 (4.5%), hysterectomy in 6 (27.3%), a single biopsy followed by hysterectomy in 2 (9.1%), multiple biopsies in 3 (13.6%) and a curettage followed by multiple biopsies and hysterectomy in 1 (4.5%). The median number of follow‐up samples was 2 (2–9) per patient. Histologically, the follow‐up samples were unremarkable (regression) in most patients (19/22, 86.4%), 2 (9.1%, aged 49 and 57 years) were diagnosed with grade 1 endometrioid carcinoma in subsequent hysterectomies, and 1 (4.5%, age 62) had persistent squamous morular metaplasia (follow‐up 69 months). In 15 patients with clinical follow‐up but no further pathology sampling, none had clinical symptoms at their last visit (100% clinical regression). Thus, the overall rate of endometrioid carcinoma was 5.4% (2/37). Conclusions Isolated squamous morular metaplasia without associated glandular neoplasia is a rare finding, reported only in 0.17% of endometrial samples. The risk of subsequent endometrioid neoplasia appears to be low (5.4%), although the possibility of undersampled atypical hyperplasia/endometrioid carcinoma cannot be completely ruled out without additional sampling. Persistent squamous morular metaplasia is relatively uncommon (4.5%) and may not lead to the subsequent diagnosis of endometrial cancer, questioning the utility of numerous repeat samplings in patients without progression after one repeat sample.

Adnexal Endometrioid Carcinomas With Sex Cord-Like Morphology are Frequently PAX8-Negative, SOX17-Positive, and Enriched for CTNNB1 Alterations

Sex cord-like morphology is now a well-known feature of occasional examples of endometrioid carcinoma of the ovary or fallopian tube. Recently, we have observed that these tumors are frequently negative for PAX8, prompting us to review their morphologic, immunohistochemical, and genomic spectrum. Twenty tumors (17 ovarian, 3 fallopian tube) with available tissue were identified in patients ranging from 32 to 78 (median 60) years. Sex cord-like patterns included cords/trabeculae (n=17), small tubular glands (n=16), and “granulosa-like” nests (n=12). In addition, 1 had ependymoma-like features with perivascular pseudorosettes and 3 had focal spindled cells. Conventional endometrioid glands were often sparse. All had conspicuous fibromatous stroma and 11 tumors had background endometrioid adenofibromas. Six tumors had associated endometriosis. PAX8 was positive in only 2/20 (diffuse in both), while SOX17 was positive in all (focal in 1, diffuse in 19). Beta-catenin showed aberrant nuclear staining in 17/20. Of the 10 sequenced tumors, 9 showed activating pathogenic variants in CTNNB1; each of these also showed nuclear beta-catenin staining. All lacked alterations in mismatch repair genes, TP53 , and POLE . In summary, adnexal endometrioid carcinomas with sex cord-like features are frequently PAX8-negative, which may result in diagnostic difficulty. However, SOX17 is typically positive and thus useful to establish the diagnosis. Most of these tumors are classified in the “no specific molecular profile” subgroup and have high rates of nuclear beta-catenin/ CTNNB1 alterations. Awareness of these morphologic and immunohistochemical associations may help avoid misclassification as sex cord-stromal or other neoplasms.

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.

Prognostic Significance of Germline DICER1 Pathogenic or Likely Pathogenic Variants in Outcomes of Ovarian Sertoli-Leydig Cell Tumor

PURPOSE Sertoli-Leydig cell tumors (SLCTs) are rare sex cord-stromal tumors, representing &lt;0.5% of all ovarian tumors. We analyze the role of germline DICER1 status in outcomes of ovarian SLCT. METHODS Patients with SLCT were enrolled in the International Pleuropulmonary Blastoma/ DICER1 Registry and/or the International Ovarian and Testicular Stromal Tumor Registry. Medical records were systematically abstracted, and those with known germline DICER1 status were selected for analysis. RESULTS Of 162 patients with SLCT, 60% had a germline DICER1 pathogenic or likely pathogenic (P/LP) variant. The adjusted 3-year recurrence-free survival (RFS) was 87.2% (95% CI, 79.4 to 95.8) for patients with a germline DICER1 P/LP variant compared with 78.1% (95% CI, 66.4 to 91.9) for those without a germline DICER1 P/LP variant ( P = .043). The adjusted 3-year and 5-year overall survival (OS) was 93.9% (95% CI, 87.3 to 100.0) for those with a germline DICER1 P/LP variant compared with the 3-year OS of 91.3% (95% CI, 83.4 to 100.0) and the 5-year OS of 78.2% (95% CI, 63.8 to 95.9) for those without a germline DICER1 P/LP variant ( P = .021). Among patients with a germline DICER1 P/LP variant, the risk of a subsequent, nonrecurrent event was 36.2% (95% CI, 21.4 to 48.1) within 10 years. Previous/concurrent and subsequent neoplasms were rare among those without a germline DICER1 P/LP variant. CONCLUSION This cohort study of patients with SLCT demonstrated that those with germline DICER1 P/LP variants had superior RFS and OS even when adjusting for other prognostic factors. Beyond prognostic implications of a germline DICER1 P/LP variant, germline testing helps identify patients at risk of subsequent neoplasms, including metachronous SLCT.

Ovarian juvenile granulosa cell tumor: A report from the International Ovarian and Testicular Stromal Tumor and International Pleuropulmonary Blastoma/DICER1 Registries

AbstractBackgroundOvarian juvenile granulosa cell tumors (juvGCT) are rare sex cord‐stromal tumors that occur primarily in children and adolescents. This study summarizes the clinical presentation and outcomes of patients with juvGCT.MethodsPatients were enrolled in the International Ovarian and Testicular Stromal Tumor and/or International Pleuropulmonary Blastoma/DICER1 Registries. Available medical records were abstracted, and pathology was centrally reviewed. Surgical staging was classified using the 2014 International Federation of Gynecology and Obstetrics (FIGO) criteria.ResultsIn total, 70 patients with juvGCT enrolled and were diagnosed between 2001 and 2024; most patients (81%, 57 of 70) presented with FIGO stage I disease. Adjuvant chemotherapy was given in 30% (21 of 70); all regimens were platinum‐based. Three‐year event‐free survival among patients with stage IA tumors was 80.2% (95% confidence interval [CI], 62.4%–100.0%), IC1 was 87.4 (95% CI, 72.4%–100.0%), IC2‐IC3 was 63.6% (95% CI, 40.7%–99.5%), and II‐IV was 48% (95% CI, 24.6%–93.8%). Of the patients with recurrent juvGCT with known mitotic index (MI), all had MI greater than 19 mitoses per 10 high power fields (HPF) at diagnosis.ConclusionOutcomes were worse for patients with FIGO stage ≥IC2 disease and for tumors with &gt;19 mitoses per 10 HPF. Given the prognostic significance of MI, the authors strongly recommend the assessment of MI for all juvGCTs. More information about tumor biology is critical to identify which patients may benefit from adjuvant chemotherapy and to facilitate the development of novel therapies.

SOX17 Expression in Mesotheliomas and Benign Mesothelial Proliferations: Implications for Differential Diagnosis With Gynecologic Carcinomas

SOX17 has recently emerged as a novel immunohistochemical marker for cancers of endometrial and ovarian origin with improved specificity compared with the widely used Mullerian marker PAX8. However, evaluation of SOX17 in benign and malignant peritoneal mesothelial proliferations remains limited, and these may mimic gynecologic carcinomas, particularly on small biopsies. We evaluated SOX17 and PAX8 expression in 20 benign mesothelial lesions (5 adenomatoid tumors, 5 well-differentiated papillary mesothelial tumors, and 10 peritoneal inclusion cysts) and 16 epithelioid peritoneal mesotheliomas. The 17 female and 3 male patients with benign mesothelial lesions ranged from 20 to 80 yr (median: 56.5 yr), while the 9 females and 7 males with mesothelioma ranged from 47 to 85 yr (median: 57.5 yr). SOX17 was positive in 5 (25%) benign lesions (2 adenomatoid tumors, 3 peritoneal inclusion cysts) and 2 (13%) mesotheliomas, while PAX8 stained 8 (40%) benign lesions (1 adenomatoid tumor, 1 well-differentiated papillary mesothelial tumor, 6 peritoneal inclusion cysts), and 2 (13%) mesotheliomas. Results for the 2 stains showed incomplete concordance, with agreement in 15 (75%) benign proliferations and 14 (88%) mesotheliomas. Our findings suggest that SOX17 positivity alone is insufficient to confirm a diagnosis of gynecologic carcinoma over a mesothelial proliferation and pathologists should exercise caution when these entities are diagnostic considerations.

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.

Low-Grade Endometrial Stromal Sarcoma

Low-grade endometrial stromal sarcomas (LG-ESS) are the second most common malignant uterine mesenchymal tumors, but in contrast to the more common leiomyosarcomas, they are often characterized by a prolonged and relatively indolent course. However, a subset of patients experience significant morbidity or die of disease, and it is difficult to predict which tumors will behave aggressively, with most published studies limited in either the number of tumors or the depth of pathologic parameters evaluated. Thus, we studied the clinicopathologic features of LG-ESS in 102 patients ranging from 21 to 74 (median: 47) years. All were treated with hysterectomy and staged according to both the FIGO 2018 system (stage IA=22, IB=36, I-not otherwise specified=5, II=16, III=13, IV=10) and the FIGO 1988 system (stage I=62, II=1, III=17, IV=22). Tumors measured 1.2-49 (median: 7) cm. Microscopically, 69 involved the endometrium while 33 were centered in the myometrium. Thirteen showed only minimal infiltration of the myometrium while the rest displayed the typical extensive myometrial permeation. The cervical stroma was involved in 18, the uterine serosa in 27, and the parametrium in 22. Conventional morphology resembling proliferative endometrial stroma was seen in 95, fibroblastic appearance in 35, smooth muscle differentiation in 23, sex cord-like differentiation in 21, stromal hyalinization in 21, and myxoid stroma in 9. Less common features included glandular differentiation resembling adenomyosis (n=5), pseudopapillary pattern (n=1), deciduoid appearance (n=2), adipocytic differentiation (n=2), multinucleated cells (n=2), and rhabdomyoblastic differentiation (n=1). Mitoses ranged from &lt;1 to 20 per 10 high-power fields (median=3). Lymphovascular invasion and infarct-type necrosis were present in 64 and 23, respectively. Follow-up was available in all patients ranging from 16 to 358 (median: 79) months. Forty-six received adjuvant treatment as hormonal therapy (n=34), radiation (n=4), radiation and hormonal therapy (n=4), chemotherapy (n=3), or chemotherapy and radiation (n=1). Three patients had persistent unresected tumor following surgery, and an additional 34 had recurrences at intervals of 3 to 272 (median: 79) months, including 2 tumors with minimal infiltration. At last follow-up, 75 patients were alive with no evidence of disease, 14 were alive with disease, and 9 died of disease at intervals of 16 to 167 (median=70) months. Four died of unrelated causes without recurrence. Five-year recurrence-free survival (RFS) and disease-specific survival (DSS) were 80% and 94%, while 10-year RFS and DSS were 51% and 87%, respectively. On statistical analysis, cervical stromal involvement (P=0.018) and myxoid stroma (P&lt;0.001) were associated with shorter recurrence-free survival. Tumors lacking a conventional component had worse disease-specific survival (P=0.048). All other clinical and morphologic features, including stage, were not significantly associated with outcome. On multivariate analysis, only cervical stromal involvement remained an independent predictor of recurrence-free survival (P=0.047; HR: 16.939) and no factors were independently predictive of disease-specific survival. Our findings highlight the difficulty in predicting outcomes in these tumors, likely due to slow progression and frequent treatment responses even in the recurrent setting. We confirm the potential for recurrence even in tumors initially showing minimal infiltration. Cervical stromal involvement and lack of conventional morphology are potential novel risk factors that should be further evaluated in subsequent studies.

Uterine Endometrial Stromal Tumors With Pure Low-Grade Morphology Harboring YWHAE::NUTM2 Fusions

Uterine endometrial stromal sarcomas (ESS) with YWHAE::NUTM2 gene fusions are typically morphologically high-grade tumors composed of atypical round cells, sometimes associated with a low-grade fibromyxoid component; they are currently included in the category of high-grade ESS (HGESS). We report 5 morphologically pure low-grade endometrial stromal tumors harboring YWHAE::NUTM2 fusions, including 1 endometrial stromal nodule (ESN) and 4 low-grade endometrial stromal sarcomas (LGESS), an association only occasionally reported previously. Patients ranged from 30 to 51 (mean=43) years and tumors from 4.5 to 7.5 cm (mean=5.7). All were stage I at diagnosis (confined to the uterus). Microscopically, the 4 LGESS showed extensive “tongue-like” invasion of the myometrium, and the ESN was entirely confined to the endometrium with no myometrial invasion. All tumors were composed entirely of morphologically uniform bland ovoid cells resembling proliferative endometrial stroma. A fibromyxoid component was seen in 1 LGESS and the ESN; in the LGESS, this was the sole component. Atypical round cells characteristic of YWHAE::NUTM2 HGESS were not identified. Mitotic count ranged from &lt;1 to 13 per 10 high-power fields (mean: 3). CD10 was positive in 2/4 (focal), estrogen receptor in 5/5 (focal=1; diffuse=4), progesterone receptor in 5/5 (focal=1; diffuse=4) and cyclin D1 was diffusely positive in 3/4. Follow-up was available in all 5 patients and ranged from 6 to 159 months (mean=72). Two patients with LGESS had recurrent disease at 15 and 155 months; 1 showed predominantly LGESS with rare round cells in the initial recurrence and pure HGESS in a subsequent recurrence, while the other patient’s recurrent tumor was predominantly HGESS (90%) in a background of focal fibromyxoid LGESS (10%). Both patients rapidly progressed and died of disease within 5 months of high-grade recurrence. We show that rare cases of morphologically pure low-grade endometrial stromal tumors, some but not all with a fibromyxoid component, harbor YWHAE::NUTM2 fusions and may recur rapidly, with transformation to HGESS and aggressive behavior. Our findings suggest that at least a subset of YWHAE::NUTM2 HGESS evolves from LGESS. We suggest that cyclin D1 and CD10 staining should be performed in all LGESS. Diffuse staining for cyclin D1 and/or negative or focal staining for CD10 should suggest the possibility of a YWHAE::NUTM2 fusion, and appropriate molecular testing should be undertaken. Since no single morphological or immunohistochemical parameter is entirely sensitive for fusion status, we also suggest that testing for a YWHAE::NUTM2 gene fusion should be considered in all cases of LGESS and, if a fusion is present, this should raise the possibility of subsequent high-grade transformation and aggressive behavior, even though such cases should still be categorized as LGESS. Although seemingly rare, ESN and LGESS with YWHAE::NUTM2 fusions may be under-recognized due to a lack of routine fusion testing.

Sclerosis in Sex Cord-Stromal Tumors Other Than the Sclerosing Stromal Tumor

Sclerosis is well-known in sclerosing stromal tumors (SSTs), as its name indicates, but has not been evaluated in other ovarian sex cord-stromal tumors (SCSTs). Its presence in other SCSTs has sporadically caused diagnostic problems in cases we have seen, and this prompted us to review SCSTs with appreciable sclerosis; tumors containing at least 20% sclerosis were included. Seventy cases were identified: 20 thecomas, 20 juvenile granulosa cell tumors (JGCTs), 8 adult granulosa cell tumors (AGCTs), 5 sex cord tumors with annular tubules, 6 retiform Sertoli-Leydig cell tumors (SLCTs; all of the intermediate differentiation), 4 nonretiform SLCTs (3 well-differentiated, 1 of intermediate differentiation with heterologous elements), 4 Sertoli cell tumors, and 3 microcystic stromal tumors (MSTs). Paucicellular sclerotic zones comprised 20% to 95% of the tumors and when conspicuous often obscured diagnostic features. Thirty-one tumors (10 thecomas, 19 JGCTs, 1 AGCT, and 1 MST) showed sclerotic zones focally enveloping nodules of tumor cells, imparting a pseudolobular appearance, and sclerosis often occurred within lobules as well. Ten of these (5 thecomas and 5 JGCTs) also had prominent staghorn blood vessels, generating a low-power appearance focally similar to SST. In 17 tumors, the sclerosis resulted in “compression” of the tumor cells into cords and/or solid tubules. Correct diagnosis in these cases is dependent on careful examination of the cellular zones of the neoplasms, but awareness of the extent of sclerosis that may be seen in diverse SCSTs may be crucial in suggesting the correct diagnosis particularly when the material is limited as in the intraoperative setting. Our findings highlight for the first time the occurrence and character of sclerosis in sex cord tumors other than SSTs and fibromas. Sclerosis is seen in descending proportion of the tumor types as follows: retiform SLCTs, thecomas, MSTs, JGCTs, sex cord tumors with annular tubules, Sertoli cell tumors, AGCTs, and nonretiform SLCTs. Its character can vary somewhat, having particular features in the sex cord tumor with annular tubules (hyaline material within tubules often coalescing and extending beyond the nests to form confluent aggregates) and retiform SLCTs (common in papillary cores).

Sclerosing stromal tumour: a clinicopathological study of 100 cases of a distinctive benign ovarian stromal tumour typically occurring in the young

AimsSince the sclerosing stromal tumour (SST) of the ovary was first described in 1973, few studies have expanded upon its histological features or overlap with other tumours. We thus investigate these aspects based on our experience with 100 cases.Methods and resultsThe patients, 14 of whom were pregnant, ranged from 12 to 63 years (median = 26 years). Ten patients had hormonal manifestations (seven oestrogenic, three androgenic). Bilateral ovarian involvement was present in two cases. Size ranged from 1 to 23 cm (mean = 8.4 cm). Most tumours were solid and white with focal yellow areas; oedema with cystic degeneration (seen in 25 cases) resulted in eight being predominantly cystic. On microscopic examination, alternating cellular and paucicellular areas (pseudolobulation) were prominent in 94 cases but seen to a limited degree in the remaining neoplasms. Admixed spindled and luteinised cells were present in all tumours, but 13 demonstrated mainly spindled cells and 19 demonstrated mainly lutein cells; 14 of the latter were from pregnant patients. The stroma was typically oedematous or collagenous, but in 14 cases was prominently hyalinised and, in four, myxoid. Prominent vascularity was present in most cases. The mitotic rate ranged from 0 to 8/10 high‐power fields (HPF), but most demonstrated &lt;1/10 HPF.ConclusionsThe differential diagnosis of SST is broad, including fibromas, thecomas, solitary fibrous tumours, pregnancy luteomas, myxomas, other ovarian sex cord‐stromal tumours with sclerosis and, rarely, Krukenberg tumours. Strict adherence to the requirement of pseudolobulation, prominent (usually ectatic) vessels, and lutein cells and fibroblasts admixed in a jumbled manner, will distinguish the neoplasm from others in the differential.

Presence and extent of lymphovascular invasion in surgical stage I squamous cell carcinoma of the cervix: a comprehensive, international, multicentre, retrospective clinicopathological study

The aim of this study was to determine whether the presence and extent of lymphovascular invasion (LVI) is prognostic in surgical stage I cervical squamous cell carcinoma (SCC). All available tumour slides and/or paraffin blocks from 426 patients with stage I cervical SCC treated surgically with curative intent were collected from 18 institutions and retrospectively analysed. Presence and extent of LVI (focal <5 spaces, extensive ≥5 spaces) were assessed on scanning magnification in large haematoxylin and eosin slide sets in 366 cases. Progression-free survival (PFS) was calculated as the time from surgery to first progression or death or last follow-up, whichever occurred first. Overall survival (OS) was defined as the time from surgery to death or last follow-up. Clinicopathological and statistical analyses were performed on 97 patients with the International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IA and 329 patients with stage IB SCC of the cervix. LVI, both focal and extensive, was more frequent in stage IB than in stage IA (p<0.001). Patients with stage IB carcinomas with extensive LVI had worse PFS [hazard ratio (HR) 2.86; 95% confidence interval (CI) 1.49, 5.49; p=0.005] and OS (HR 2.88; 95% CI 1.38, 6.02; p=0.012) than those with focal or no LVI. In stage IA, in contrast, the presence and extent of LVI did not associate with PFS (p=0.926) or OS. Extensive LVI was not statistically correlated with PFS and OS in substages IA1, IA2 or IB2. PFS (HR 3.7; 95% CI 1.61, 8.46; p<0.001) and OS (HR 4.18; 95% CI 1.58, 11.04; p=0.002) in stage IB1, and PFS (HR 7.78; 95% CI 0.87, 69.82; p=0.039) in stage IB3 were diminished in the presence of extensive LVI. In conclusion, in patients with FIGO stage I cervical SCC, the presence and extent of LVI has prognostic significance in stage IB carcinoma, and quantifying LVI is recommended.

DICER1-Related Primitive Polyphenotypic Neoplasm

Somatic or germline pathogenic/likely pathogenic variants in DICER1 have known associations with certain neoplasms in the gynecologic tract, including Sertoli-Leydig cell tumors, embryonal rhabdomyosarcoma, and adenosarcoma. However, recent studies have highlighted DICER1- related malignant neoplasms with complex admixtures of sarcomatous, primitive glandular, and/or neuroectodermal elements, which are underrecognized and lack consistent nomenclature. We report the largest series of these primitive polyphenotypic DICER1 -related neoplasms arising in the gynecologic tract or peritoneum. The 15 patients were aged 10 to 77 (median: 37) years. Tumors involved the endometrium (n=6), cervix (n=3), endometrium and cervix (n=2), ovary (n=2), or pelvic peritoneum (n=2). Twelve were organ-confined and 3 were at an advanced stage at presentation. All contained sarcomatous elements composed of sheets and aggregates of ovoid/spindled cells with rhabdomyoblastic differentiation in 13. Periglandular condensation (n=13), cambium layer (n=12), fetal-type cartilage (n=11), and anaplasia (n=4) were also identified. Primitive glands were present in 14 (abundant in 8) and comprised single or clustered simple (n=14) or variably dilated/elongated glands resembling those seen in adenosarcoma (n=9). The epithelium had a primitive appearance with frequent subnuclear vacuoles (n=14), intracytoplasmic granules (n=7), or minimal amphophilic cytoplasm (n=3), and frequently stained for SALL4, glypican-3, and AFP. Neuroectodermal elements were seen in 12, composed of compact small round blue cells punctuated by neuroepithelial tubules. DICER1 alterations were present in all tumors. DICER1 -related primitive polyphenotypic neoplasms present significant diagnostic difficulty due to their varied appearances and lack of consistent nomenclature in the rare reports to date. Recognition of the morphologic features of these unusual neoplasms should prompt confirmatory DICER1 testing and consideration of germline evaluation, particularly in young patients.