RESUMEN
Carcinosarcoma of the urinary bladder is a very rare neoplasm accounting for less than 0, 05%of urothelial tumours is a biphasic malignant neoplasm with only 79 cases reported in the English literature. Histologicaly, it exhibits morphologic and/or immunohitochemical evidence of epithelial and mesenchymal differenciation with the presence or absence of heterologous elements. It usually involves aged adults after 60 years and it has a poor prognosis. We report three cases with an emphasis on unusual histologic features. Three male patients age 76 to 86 years were found to have polypoide masses in the urinary bladder. In all cases, microscopic examination revealed biphasic neoplasms with distinct mesenchymal and epithelial components. The two first cases were remarkable respectively by the presence of chondrosarcomasrcomatous and osteosracomatous components