Abstract
BACKGROUND: During embryonic development in women, a regression of temporary embryonic structures - mesonephric (Wolffian) ducts occurs. Adnexal tumors of Wolffian duct origin (FATWO) are rare. CASE REPORT: We presented the case of a 64-year-old female patient who was diagnosed with FATWO. After the surgical treatment, the uterus with bilateral adnexal structures was submitted for histopathological analysis. The left ovary was occupied by a tumor measuring 80 × 60 × 50 mm, with smooth, shiny, whitish surface. Tumor cells were medium-sized, relatively uniform, round, and polygonal, with eosinophilic cytoplasm and centrally laid nucleus with fine chromatin, organized into solid, trabecular, and tubular formations. Tumor cells were positive for pancytokeratin (CK), CK7, CD10, neuron-specific enolase (NSE), synaptophysin, calretinin, progesterone, estrogen, and epithelial membrane antigen (EMA). CONCLUSION: This case adds a report of a rare tumor to the literature. We must think of it in the differential diagnostic algorithm to make an accurate diagnosis for selecting the best treatment modality.