Mesonephric
adenocarcinoma is a rare
tumor type that is usually found in areas where the Wolffian duct was present during the fetal period. We report a case of mesonephric
adenocarcinoma of the uterine corpus in a 66-year-old woman who presented with
vaginal bleeding. Pelvic magnetic resonance imaging revealed a 2.7-cm-sized irregular thickening and enhancement of the uterine body. The diagnosis following endometrial
curettage biopsy was
endometrioid adenocarcinoma, and the patient underwent a total
hysterectomy with bilateral
salpingo-oophorectomy. The
tumor was composed of small tubular and ductal components, and a retiform appearance was also observed in the deeper areas. The
tumor cells were immunopositive for
cytokeratin,
vimentin, CD10 with a
luminal staining pattern, PAX2, and PAX8, and immunonegative for
estrogen receptor and
progesterone receptor, which was consistent with
tumor of mesonephric origin. Mesonephric
neoplasms reveal relatively low-grade nuclear feature, characteristic immunoprofiles (immunonegative for ER and PR, and immunopositive for CD10, PAX2, PAX8, and GATA3), and unique
tumor location (myometrium), whereas Müllerian
neoplasms such as endometrial
adenocarcinoma show various morphology, immunopositivity for ER and PR, and primarily endometrial location. As described above, an integration of the clinical features, morphologic characteristics, and immunohistochemical profiles is needed to make a diagnosis.