International TNM Staging System for Kidney Cancer
Primary Tumor (T)
T1a = Confined to kidney and less than 4 cm in size
T1b = Confined to the kidney and between 4 and 7cm in size
T2 = Confined to the kidney and greater than 7 cm in size
T3a = Outside renal capsule invading the adrenal, renal sinus or perinephric fat
T3b = Tumor is invading the renal vein
T3c = Tumor is invading the vena cava
T4 = Tumor is outside Gerota�s fascia and is invading adjacent organs

Regional Lymph Nodes (N)
N0 = No regional lymph node metastasis
N1 = Metastasis in a single regional lymph node
N2 = Metastasis in more than one regional lymph node

Distant Metastasis (M)
M0 = No distant metastasis
M1 = Distant metastasis

Copyright 2006 Kidney Cancer Institute