Choriocarcinoma and transitional cell carcinoma of the bladder--a case report and review of the clinical evolution of disease in reported cases.

The sixth reported case of choriocarcinoma associated with transitional cell carcinoma (TCC) of the bladder is described. A 67-year-old female presented with haematuria and was found to have a bladder tumour with both poorly differentiated TCC and trophoblastic elements. The tumour was confirmed as being limited to the bladder at laparotomy. The patient was treated with combination chemotherapy but, after an initial response, relapsed and died of disease. Postmortem examination revealed multiple metastatic choriocarcinoma and no TCC. A review of the clinical evolution in the reported cases suggests that transitional cell carcinoma is the cell of origin of these tumours by the process of progressive retrodifferentiation.