Sarcomas of the kidney.

Sarcomas of the kidney are exceedingly uncommon. They represent between 1 and 3% of all malignant renal tumors. Several histological types have been reported. We have reviewed the renal tumors diagnosed in our department in the last 25 years and found 4 cases of sarcoma out of 390 malignant renal tumors (1.02%). They were a liposarcoma, a storiform-pleomorphic fibrous malignant histiocytoma, a rhabdomyosarcoma and a pleomorphic leiomyosarcoma. We report the clinical data and the outcome of the patients, together with the immunohistochemical and ultrastructural findings in these cases.