| Grading |
Criteria and content |
| Grade 0 |
Tumor thrombus confined to the renal vein |
| Grade I |
Tumor thrombus invades the inferior vena cava and the tip of the thrombus is ≤2 cm from the opening of the renal vein |
| Grade II |
Invasion of the tumor thrombus into the inferior vena cava below the level of the hepatic vein, with the tip of the tumor thrombus >2 cm from the opening of the renal vein |
| Grade III |
Tumor thrombus growing to the level of the inferior vena cava in the liver, below the diaphragm |
| Grade IV |
Tumor thrombus invades the inferior vena cava above the diaphragm |