Nephron-sparing radical excision of a giant perirenal liposarcoma involving a solitary kidney.

We describe our experience in a patient with a congenital solitary kidney encased by a perirenal liposarcoma managed by nephron-sparing excision. The best predictor of survival with liposarcoma is complete resection of the tumor. Generally a diffuse peri-renal liposarcoma arising within Gerota's fascia would necessitate a radical nephrectomy. Having a congenitally solitary kidney, this patient refused nephrectomy, therefore a kidney-sparing excision of his liposarcoma was attempted. To obtain negative margins and to provide a nephron-sparing excision, the capsule of the kidney was resected with the mass. Direct extension into the diaphragm necessitated an en bloc resection of 4 x 6 cm of the left hemidiaphragm. The defect was reconstructed with a Gortex patch graft. Pathology revealed a 32 x 22 x 8-cm liposarcoma with areas of sclerosing liposarcoma and poorly differentiated spindle cell sarcoma, focally Grade 3 of 3, with the remaining tumor being Grade 1. There was diaphragmatic invasion, but all surgical margins were negative. At 22 months CT follow-up, the patient has no radiographic evidence of disease. Excision of this mass with the renal capsule allowed our patient to be margin negative and maintain normal renal function. This is the only report in the literature describing nephron-sparing resection of a giant perirenal liposarcoma involving a solitary kidney.