Chondrosarcoma of the urinary bladder: report of a case with immunohistochemical and ultrastructural findings and review of the literature.

A primary chondrosarcoma arising in the urinary bladder is described in a 73-year-old female, together with a review of the 2 previously reported cases in the literature. The clinical symptoms are similar to transitional cell carcinoma, but chondrosarcoma usually presents at an advanced stage, and the outcome is rather poor. This very rare and commonly poorly differentiated tumor should not be confused with poorly differentiated transitional cell carcinoma. The differential diagnosis from other lesions with chondroid features, such as chondroid metaplasia, osteosarcoma and carcinosarcoma, is discussed. The value of immunohistochemistry and electron microscopy in the differential diagnosis is demonstrated.