Benign angiomyolipoma involving the renal vein and vena cava as a tumor thrombus: case report.

A 53-year-old woman presented with a renal angiomyolipoma extending as a thrombus into the renal vein and vena cava. This case is most unusual and we are unaware of any report of a benign angiomyolipoma that has presented as a tumor thrombus. The intravascular growth of a benign angiomyolipoma has previously been described.