Robson Stage for RCC 1
Stage I Confined within renal capsule
Stage II Perinephric stranding, perinephric collateral or soft tissue mass in perinephric space
Stage III
A Filling defect within a distended vein; direct continuity of thrombus with primary mass
B Lymph nodes ≥1 cm
Stage IV-
A Obliteration of normal soft tissue planes between tumor and adjacent organs
B Metastases enhance with IV contrast material (hepatic metastases in arterial phase)