Primary choriocarcinoma of the urinary bladder.

A case of choriocarcinoma of the urinary bladder is presented. A 57-year-old man underwent a cystectomy for transitional cell carcinoma, grade II. Choriocarcinoma was found, in addition to the transitional cell carcinoma, in the removed urinary bladder. After the operation, metastases appeared in both lungs, evolving rapidly despite chemotherapy. The patient died five months after admission. Immunohistochemically, staining for human placental lactogen was strongly positive, and both alpha and beta subunits of human chorionic gonadotropin were weakly positive in the primary site of the removed urinary bladder and in the metastatic foci.