RCC has a strong propensity to venous tumor invasion which is seen in up to 20% of cases, with extension into the IVC in 4 to 15% of cases. Renal vein invasion classifies RCC as TNM stage T3 and Robson stage 3A. Tumor thrombus is distinguished from bland thrombus by contrast enhancement on CT and MRI and color flow on ultrasound. Other tumors with a strong tendency to venous invasion are hepatocellular carcinoma and adrenal carcinoma.

Credit: Dr Donna D'Souza.