Abstract
This is a report of a case of carcinosarcoma/sarcomatoid carcinoma (CS/SC) of the urinary bladder. The patient underwent multiple excisional biopsies of the urinary bladder. Following development of multiple lung metastases, the patient died at 21 months after diagnosis. This case represents a very rare example of CS/SC of the urinary bladder with a malignant fibrous histiocytoma component that was characterized by morphologic and immunohistochemical findings, and proves that CS/SC of the urinary bladder is a very aggressive neoplasm. Analysis of the tumor indicated that different factors other than p53 may be associated with the growth of this tumor.