A case of angiomyolipoma presenting as a huge retroperitoneal mass.

A 60-year-old man was admitted to Hitachi General Hospital, Hitachi, Japan, with general fatigue and epigastric fullness. A large mass was palpated on whole abdomen and abdominal computed tomography scan showed a large lobulated fatty mass surrounding the right kidney, which indicated the existence of angiomyolipoma arising from the right kidney. The tumor was success-fully resected through a thoracoabdominal incision. The total weight of the resected specimen was 3500 g, apparently the largest angiomyolipoma resected by operation in Japan.