Female adnexal tumor of probable Wolffian origin (FATWO) is a rare disease entity that arises from the mesonephric duct system. FATWO is different than other gynecological cancers in terms of embryology. Here, we describe the case of a 52-year-old woman with malignant FATWO. The patient underwent explorative laparotomy and surgical staging after a frozen section revealed malignancy. Detailed examination of the pathologic findings were consistent with FATWO. Counseling and further testing were provided to the patient to assess the risk of germline mutation and epigenetic change. An O-6-methylguanine-DNA methyltransferase gene methylation test was positive, and all other tests were normal. This is the first study to report a case of O-6-methylguanine-DNA methyltransferase methylation with FATWO in Korea.

ObjectivesBorderline ovarian tumors (BOT) are premalignant lesions. Approximately 10% of all epithelial ovarian cancers are known to be hereditary with hereditary breast and ovarian cancer (HBOC) accounting for approximately 90% of cases; the remaining 10% are attributable to Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC). The aim of our study is to estimate this risk based on screening immunohistochemistry (IHC).MethodsThirty-four patients diagnosed with BOT were identified. Family history, clinical characteristics, and IHC data (breast cancer 1, early onset [BRCA1], breast cancer 2, early onset [BRCA2], mutS homolog 2 [MSH2], mutL homolog 1 [MLH1]) were collected for all cases from the patients' medical charts. Nuclear staining of the tumor was scored as negative and positive.ResultsAmong 32 patients, 14 (44%) had serous type and 18 (56%) had mucinous type. The mean patient age was 44 years (range 19-86).The number of patients with weak IHC staining for MSH2 and BRCA2 was 1 (3%) and 6 (19%) respectively. The median follow up was 21.8 months.ConclusionAccording to the results, we discovered that 3% and 19% of patients with BOT had a risk of hereditary cancer based on IHC analysis respectively. This pilot study may help clinician to counsel effectively for confirmative tests.

This study was to investigate the frequency of mismatch repair deficiency/high microsatellite instability (MMRd/MSI-H) in gynecologic malignancies and the efficacy of immune checkpoint inhibitors (ICIs) in patients with recurrent gynecologic cancers according to MMR/MSI status. Materials and MethodsWe conducted a multi-center retrospective review on the patients who were diagnosed with gynecologic cancers between 2015 and 2020. Their clinicopathologic information, results of immunohistochemistry staining for MLH1/MSH2/MSH6/PMS2 and MSI analysis, tumor response to treatment with ICIs were investigated. ResultsAmong 1,093 patients included in the analysis, MMRd/MSI-H was most frequent in endometrial/uterine cancers (34.8%, 164/471), followed by ovarian, tubal, and peritoneal cancers (12.8%, 54/422) and cervical cancer (11.3%, 21/186). When assessed by histology without regard for cancer types, the frequency of MMRd/MSI-H was 11.0% (38/345) in highgrade serous adenocarcinoma, 38.6% (117/303) in endometrioid adenocarcinoma, and 30.2% (16/53) in carcinosarcoma. A total of 114 patients were treated with ICIs at least once. The objective response rate (ORR) was 21.6% (8/37) in cervical cancer, 4.7% (2/43) in ovarian cancer, and 25.8% (8/31) in endometrial/uterine cancers. Univariate regression analysis identified MMRd/MSI-H as the only significant factor associated with the ORR (28.