A case of endometrioid carcinoma of the fallopian tube mimicking an adnexal tumor of probable Wolffian origin.

We report a very uncommon case of endometrioid adenocarcinoma of the fallopian tube that mimicked, based on histology, a female adnexal tumor of probable Wolffian origin (FATPWO). We present our microscopic and immunohistochemical findings, and a review of the literature concerning these two entities. The differential diagnosis can be of great consequence, owing to the very different prognoses of the two tumors, and is based mainly on macroscopic appearance and immunohistochemical profile: epithelial membrane antigen (EMA) and CA125, generally lacking in FATPWO, are expressed in endometrioid adenocarcinoma, thus indicating the müllerian origin of this tumor.