Metastatic choriocarcinoma in a middle-aged man presenting as a right thigh mass with venous thrombosis: a case report.

Choriocarcinoma is a highly aggressive beta-subunit of human chorionic gonadotropin (betaHCG)-producing germ cell tumor. In men, it is a rare neoplasm and can arise in the testes or in various extragonadal locations such as the retroperitoneum, mediastinum, and pineal body. We present a highly unusual case of a middle-aged man with primary metastatic betaHCG-producing choriocarcinoma of the right thigh along with right lower-extremity venous thrombosis. We comment on prognostic variables as well as discuss several theories to account for the unusual location of his choriocarcinoma.