[Primary choriocarcinoma of the bladder. A case report with immunohistochemical and ultrastructural study]

Some tumors frequently encountered in other organs and usually with a high grade of malignancy and a poor prognosis have been recently described in the urinary bladder, very often in close relationship with a pre-existing transitional cell carcinoma. Of these, primary choriocarcinoma of the urinary bladder is one of the most uncommon and its histogenesis much discussed. It is important to identify this tumor type, since a change in the oncologic treatment may be warranted. We report an additional case of this rare bladder tumor with clinicopathologic study and discuss the histogenetic and therapeutic aspects.