Intracaval extension of renal cell carcinoma.

Intravenous extension occurs in many patients with renal cell carcinoma. Preoperative recognition is essential as venous involvement alters the surgical approach and clinical staging of the tumours. The venous extension of tumor has a characteristic arteriographic appearance, the recognition of which should prompt venacavography. Computerized body tomography (CBT) may also detect renal vein and caval extension and provide evidence of early ascites from the Budd Chiari syndrome associated with hepatic vein obstruction from intracaval tumor extension. However, it may be difficult to distinguish intracaval blood clot and tumor on the basis of CBT criteria alone. Of the four patients with intracaval growth of renal cell carcinoma, three received preoperative therapeutic tumor embolization, a procedure that carried no additional risk of tumor detachment and embolization.