[Carcinosarcoma of the bladder. Apropos of two cases]

The authors report two cases of carcinosarcoma of the bladder, review the literature, and study the clinical, histological, therapeutic and evolutive aspects of this unusual tumor. It is a rare tumor which represent less than 0.5 per cent of all cancers of the bladder. It is three times more frequent in men than in women. Hematuria is the most frequent alarming symptom and pathogenesis is still a matter of debate. Diagnosis is based on the pathological examination including immunohistochemical study and, if necessary, with electron microscopy examination. The tumor contains two highly malignant cellular components: one is epithelial and the other is mesenchymal. Treatment is not well codified. Early diagnosis and radical cystectomy seem to improve the prognosis, which is usually poor. 5 year survival rate is about 20 per cent.