Endometrioid carcinoma of the endometrium with sertoliform differentiation.

Ovarian endometrioid tumors with areas mimicking sex cord-stromal tumors are well documented in the literature, but it is unclear whether a similar tumor occurs in the endometrium. We report here a patient with an endometrial endometrioid adenocarcinoma resembling a Sertoli cell tumor. Immunohistochemical and ultrastructural investigations proved it was an adenocarcinoma rather than a true sex cord-stromal tumor. The features of the endometrial tumor were similar to those described in ovarian endometrioid tumors mimicking sex cord-stromal tumors and we compare them to true sex cord-stromal cell tumors. This case confirms that endometrioid adenocarcinoma with sertoliform differentiation can arise in the endometrium as well as in the ovary.