Primary choriocarcinoma of the urinary bladder. Report of a case with probable epithelial origin.

The seventh case of primary choriocarcinoma of the urinary bladder is presented. The results of initial bladder biopsies on this 82-year-old male patient revealed a poorly differentiated urothelial carcinoma and carcinoma in situ. The diagnosis of choriocarcinoma was established at autopsy, and confirmed by the demonstration of chorionic gonadotropin by immunoperoxidase technique. The literature is reviewed and a possible epithelial origin of this rare tumor is discussed.