A Case of Renal Capsular Liposarcoma with Intracaval Fat Thrombus

A 58-yr-old woman was referred to our hospital for hematuria and a painless, rapidly growing abdominal mass. Computed tomography showed a rounded mass, 23 × 19 cm in diameter, spread over the left retroperitoneal space. A thrombus was observed occupying the left renal vein until the vena cava. Total left nephrectomy with excision of the retroperitoneal mass was carried out. A cavotomy highlighted the intraluminal thrombus, which was easily detached with a forced Valsalva maneuver. The pathologic examination demonstrated a well-differentiated liposarcoma of the renal capsule with fat thrombus in the vena cava. At 24 mo follow-up, there was no evidence of recurrence.