Coexisting epithelioid trophoblastic tumor and choriocarcinoma of the uterus following a chemoresistant hydatidiform mole

The epithelioid trophoblastic tumor is an unusual type of trophoblastic tumor. Herein, we describe a patient with coexisting epithelioid trophoblastic tumor and choriocarcinoma in the uterus. The patient had a history of hydatidiform mole with recurrent elevation of human chorionic gonadotrophin level that is resistant to chemotherapy. Histopathologic and immunohistochemical examination showed distinctive differences between the 2 trophoblastic tumors. The development of epithelioid trophoblastic tumor may be related to the persistence of locally invasive disease, which was unresponsive to chemotherapy. The patient responded well to surgery. The presence of an epithelioid trophoblastic tumor should be considered in chemoresistant gestational trophoblast tumor.