Figure 1From: Prognostic benefit of surgical management in renal cell carcinoma patients with thrombus extending to the renal vein and inferior vena cava: 17-year experience at a single center Classification of tumor thrombus level according to the Mayo staging system. Level 0, thrombus extending to the renal vein; level I, thrombus extending into the IVC to no more than 2Ā cm above the renal vein; level II, thrombus extending into the IVC to more than 2Ā cm above the renal vein but not to the hepatic vein; level III, thrombus extending into the IVC to above the hepatic vein but not to the diaphragm; and level IV, thrombus extending into the supradiaphragmatic IVC or right atrium.Back to article page