Malignant renal tumor with extension to the inferior vena cava.

Background: Management of malignant renal tumors involving the inferior vena cava (IVC) depends on tumor extension within the cava.

Methods: Of 295 patients treated for renal cancer, propagation of tumor mass through the renal vein to IVC was seen in 22 (7%) patients. Cephalad extension of the tumor was suprarenal: infrahepatic in 12, retrohepatic in 6, and within the right atrium in 4 patients.