Synchronous Bilateral Ovarian Carcinomas With Right Mesonephric-like Adenocarcinoma and Left High-grade Serous Carcinoma: A Case Report and Review of the Literature.

Mesonephric-like adenocarcinomas (MLAs) are rare neoplasms of the uterus corpus and ovary, while high-grade serous carcinoma (HGSC) is the most common and lethal epithelial ovarian malignancy. We report a case of a 56-yr-old woman who presented with bilateral solid and cystic ovarian masses. She underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy, lymphadenectomy, omentectomy, and peritoneal biopsies. Histopathologic examination of the bilateral ovarian masses revealed 1 ovary with MLA, and the other ovary showed HGSC in association with serous tubal intraepithelial carcinoma. The morphology, immunophenotypes, and molecular profiling of the HGSC and the MLA were distinct and as expected for the different tumor types: HGSC was diffusely positive for WT-1, estrogen receptor, and p53 (mutant pattern), while negative for GATA-3 and TTF-1; MLA was positive for GATA-3 and TTF-1, while negative for WT1, estrogen receptor, and p53 (wild-type pattern); both tumors were diffusely positive for PAX-8. The HGSC revealed a TP53 c.659A>G (p.Y220C) mutation, and the MLA revealed a KRAS c. 34G>T (p. G12C) mutation and a PIK3CA c. 1034A>T (p. N345I) mutation. To the best of our knowledge, this is the first reported case of synchronous bilateral ovarian carcinomas with MLA and contralateral ovarian HGSC.