[Renal sarcomatoid carcinoma. Report of 9 cases]

We reviewed 9 cases of sarcomatoid carcinoma of the kidney from 233 cases of renal carcinoma that had undergone surgery over a period of 21 years (1970-1991). The principal characteristics (patient age, sex, diameter, clinical features, stage, grade, mitotic index, radiological features) were analyzed and compared with the rest of the series. This histological type is distinct from other types of renal carcinoma in that it carries a poor prognosis (with a mean survival of 6 months), it is usually diagnosed in the advanced stages, with a high mitotic index and tumor grade. It presents no special clinical and radiological features which make it distinct from the other histological types of renal carcinoma.