Malignant gonadal stromal tumor of the testis arising with a malignant teratoma.

We report a case of a rare malignant gonadal stromal tumor arising with a malignant teratoma of the testis. The malignant gonadal stromal element of the tumor or the nongerminal cell component was resistant to chemotherapy and ultimately metastasized to the lymph nodes, lung, bones and liver. Nongerminal cell tumors arising with germinal cell neoplasms may become more common because the chemosensitive germ cell tumor may be destroyed and the chemoresistant nongerminal tumor remains. The nongerminal cell tumor is the most important prognostic factor and also dictates possible later changes in therapy.