Sarcomas and sarcomatoid and mixed malignant tumors of the kidney in adults—part I

As the first part of a three-part study based on 80 cases of unusual renal tumors in adults, 26 cases of primary renal sarcoma are presented, including 15 leiomyosarcomas, five hemangiopericytomas, five liposarcomas and one pleomorphic rhabdomyosarcoma. Capsular localization was a feature of more than half the tumors (including all the liposarcomas), although some of the tumors were situated in relation to the renal pelvis or within the parenchyma. The clinical course of these tumors was that of aggressive malignancy, resulting in the death of 21 of the 26 patients. There were no associated features of the tuberous sclerosis complex among these cases.