Stage I

Tumor is limited to the kidney or surrounded with fibrous pseudocapsule. The renal capsule or pseudocapsule may be in-filtrated with the tumor, but it does not reach the outer surface. Tumor is completely resected.

- Tumor may be protruding into the pelvic system and “dip- ping” into the ureter but not infiltrates its wall.

-T vessels of the renal sinus are not involved.

- Intrarenal vessel involvement may be present.

Tumor is limited to the kidney and completely resected.

- Tumor was not ruptured before or during removal - The vessels of the renal sinus are not involved beyond 2 mm.

-There is no residual tumor apparent beyond the margins of excision.

Stage II

The tumor extends through the renal capsule into perirenal fat but is completely resected.

- The tumor infiltrates the renal sinus and/or invades blood and lymphatic vessels outside the renal parenchyma but is completely resected.

- The tumor infiltrates adjacent organs or vena cava but is completely resected.

- Tumor extends beyond the kidney but is completely excised.

- No residual tumor is apparent at or beyond the margins of excision

- Tumor thrombus in vessels outside the kidney is stage II if the thrombus is removed in block with the tumor.

Stage III

Incomplete excision of the tumor which extends beyond resection margins - any abdominal lymph nodes are involved - tumor rupture before or intraoperatively - the tumor has penetrated through the peritoneal surface - tumor thrombi present at resection margins of vessels or ureter.

- The tumor has been surgically biopsied prior to preoperative chemotherapy or surgery.

Residual tumor confined to the abdomen.

- Lymph nodes in the renal hilum or the periaortic chains.

- Diffuse peritoneal contamination by the tumor.

- Implants are found on the peritoneal surfaces.

- Tumor extends beyond the surgical margins either microscopically or glossy.

- Tumor is not completely respectable because of local infiltration into vital structures.

Stage IV