Computerized tomographic demonstration of inferior vena caval tumor thrombus from renal angiomyolipoma

A case of renal angiomyolipoma with gross venous tumor thrombus extension into the inferior vena cava is presented. This fatty tumor thrombus is visualized easily by computerized tomography and is confirmed by inferior venacavography, surgery and histology. Macroscopic renal vein and vena caval tumor thrombi rarely occur in patients with angiomyolipoma and may be diagnosed preoperatively by the demonstration of abundant fat within the tumor components.