The case of a patient with a uterine tumor resembling an ovarian sex cord tumor is reported. This tumor is designated, according to the features described by Clement and Scully, as group II. The predominantly tubular pattern and the lipid-rich cells created an appearance indistinguishable from that of an ovarian Sertoli cell tumor. Ultrastructurally, a structure that resembled a Charcot-Böttcher crystal was observed. From this observation, it is hypothesized that the neoplastic cells showed Sertoli cell differentiation.