Synchronous bilateral testis tumor: mixed germ cell and theca cell tumors.

Synchronous bilateral testis tumors of different histologic types are rare. All previous cases have demonstrated germ cell tumors on both sides. The simultaneous appearance of a germ cell tumor and a contralateral non-germ cell tumor has not been reported. We herein report a thirty-four-year-old man who presented with a mixed non-seminomatous germ cell tumor of the left testis and theca cell tumor of the right testis.