[Sarcomatoid renal carcinoma].
OBJECTIVE: To analyze the pathological and clinical features of a variant of renal carcinoma: sarcomatoid renal carcinoma. METHODS: Of 316 patients diagnosed as having a renal tumor from 1975 to 1995, 11 (3.5%) with a pathological diagnosis of sarcomatoid renal carcinoma were analyzed. The clinical history, biological data and diagnostic imaging findings of these patients were reviewed. All patients had undergone surgical exploration. RESULTS: All the tumors showed a double cellular population, with a fusiform component. Histological analysis showed a high grade and stage tumor. Ten patients died from the disease, the mean survival rate was 9 months (range 2-48) following diagnosis. CONCLUSIONS: Sarcomatoid carcinoma of the kidney is uncommon and can be occasionally difficult to distinguish from sarcoma. It has a worse prognosis than other variants of renal carcinoma.