Lars-Christian Horn

Mesonephric-like adenocarcinomas of the uterine corpus: report of a case series and review of the literature indicating poor prognosis for this subtype of endometrial adenocarcinoma

Endometrial mesonephric-like adenocarcinoma (ML-AC) represents a recently recognized subtype of endometrial adenocarcinoma (AC) associated with a subtle immunophenotype with a characteristic KRAS-mutation. Detailed clinico-pathologic analyses and prognostic data on ML-AC are limited. We report a series of four cases with histopathological, immunohistochemical, and molecular analyses. These cases as well as the data of previously published cases were reviewed for clinico-pathologic variables and clinical follow-up information. Forty cases of ML-AC were identified. ML-AC represents about 1% of all endometrial carcinomas. Similar to other types of endometrial AC, vaginal bleeding was the leading presenting symptom, and the mean age was 60.0 years (range 31-91). More than a half of the patients presented with locally advanced disease (≥ FIGO stage II) at time of diagnosis, developed a recurrence or died of the disease within a mean follow-up period of 24.7 months (range 3-144.5 months). The most common site of distant disease was pulmonary involvement. Microscopically, ML-ACs present with mixed morphology and show a co-expression of so-called mesonephric and Müllerian markers, suggesting a Müllerian origin of the tumors. Immunostaining for PD-L1 was negative in all tested cases, using different antibodies against PD-L1. Retained staining for mismatch repair proteins on immunohistochemistry and a POLE-mutation suggest a copy number low phenotype within the molecular classification of endometrial carcinomas. Almost all cases showed a KRAS-mutation at codon 12 (mostly G12V). Uterine ML-AC represents a distinct subtype of invasive endometrial AC, associated with KRAS-mutations and characteristic immunohistochemical findings. Clinically, ML-AC may show an aggressive behavior with a high rate of recurrent disease and a substantial risk for distant metastatic disease, especially to the lungs.

Increase of fallopian tube and decrease of ovarian carcinoma: fact or fake?

Accurate disease classification is fundamental for the selection of the treatment approach, prognostication, selection of clinical trials and for research purposes in routine clinical practice. Extrauterine high-grade serous carcinoma (HG-SC) may arise from the ovary, the fallopian tube and rarely from the peritoneal surface epithelium. Regardless of its origin, the vast majority of patients with HG-SC share clinical symptoms, present with advanced stage disease and suffer from a poor prognosis. Recent data suggest that there is an increasing incidence of HG-SC arising from the fallopian tube. Data from the Clinical Cancer Registry of Leipzig of surgically treated non-uterine pelvic carcinomas were analyzed regarding their sites of origin. Depending on the histology, cases were separated into high-grade serous and non-high-grade serous tumors. Based on different approaches in the assessment of the site of origin, three distinct time periods were defined. The frequency of the specific sites of origin was compared to the different time periods and histologic subtypes. The majority of cases (57.9%; 279/482) were high-grade serous carcinomas, 42.1% of the cases presented with endometrioid, clear cell or mucinous histology. Overall, a 1.7-fold decrease of carcinomas with ovarian origin, paralleled by a 10.3-fold increase of tubal carcinomas was noted between 2000 and 2019. Based on the histopathological subtype, there was a 2.1-fold decrease of ovarian and a 7.1-fold increase of tubal carcinomas in patients with HG-SC. In non-high-grade serous tumors, the frequency of the different sites of origin did not change. 83.7% of tumors with non-high-grade serous histology originated from the ovary, whereas 86.8% of the carcinomas with tubal origin were of high-grade serous histology. The present and published data of non-uterine pelvic cancers may suggest an increase of tubal and decrease of ovarian carcinomas. However, there is rising morphologic and molecular evidence that non-uterine HG-SC actually arise from the fallopian tubes via its precursor STIC instead of from the ovary. This evidence has had an impact on the handling and reporting of non-uterine surgical specimens and its definition of the site assessment. In conclusion, the increasing frequency of tubal carcinomas and the associated decrease in ovarian cancer appears to be due to the reclassification of tumors previously classified as ovarian and greater emphasis on examining the resection specimens of non-uterine pelvic carcinomas.

Epithelial–mesenchymal transition (EMT) in vulvar cancer with and without inguinal lymph node involvement

Abstract Purpose Epithelial-mesenchymal transition (EMT) is associated with increased metastatic spread and poor prognosis. Data on vulvar carcinoma are limited. Methods Thirty-two cases of squamous cell carcinoma of the vulva (16 with and 16 without inguinal lymph node metastases) and their lymph node deposits were evaluated for immunohistochemical expression of EMT markers (vimentin, cyclin D1, e-cadherin), p16, p53 and Ki-67. Results of EMT-immunostainings were compared to lymph node involvement and expression of p53 and p16. The micro-anatomical staining pattern for EMT markers comparing the tumor center with the front of invasion was analysed in each tumor. Results There was no difference in the expression of EMT markers between node negative and node positive tumors. Staining for vimentin and cyclin D1 was seen within tumor cells at the front of invasion in 100 and 84.4% of the tumors, respectively. The majority of cases (68.7%) showed negative or reduced staining for e-cadherin in this micro-anatomical localization. Tumor cells within the lymph node metastases showed positive staining for e-cadherin in 75% and for cyclin D1 in 49% of the cells but were negative for vimentin in 13 out of 16 cases (81.3%). Tumors with aberrant p53 staining represented a non-significant higher vimentin but significantly higher cyclin D1 expression at the front of invasion than those with p53 wild-type pattern. Conclusion The present study shows no differences in the expression of EMT markers between node positive and node negative vulvar cancers. The evaluation of immunostaining within the micro-anatomical context indicates that an EMT-phenotype is restricted to the tumor cells at the front of invasion. Paired analyses of vulvar carcinomas and their lymph node deposits suggest mesenchymal-epithelial transition (MET) in the metastatic deposits. Immunohistochemical staining results may suggest that EMT is more prevalent in vulvar cancer with aberrant p53 staining.