Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

Table 1 New tumor, node, metastasis classification system for renal cell carcinoma

T-primary tumor
Tx	Primary tumour cannot be assessed
T0	No evidence of primary tumour
T1	Tumour ≤ 7 cm in greatest dimension, limited to kidney
T1a	Tumour ≤ 4 cm in greatest dimension, limited to kidney
T1b	Tumour > 4 cm but ≤ 7 cm in greatest dimension, limited to kidney
T2	Tumour > 7 cm in greatest dimension, limited to kidney
T2a	Tumour > 7 cm but ≤ 10 cm in greatest dimension, limited to kidney
T2b	Tumour > 10 cm in greatest dimension, limited to kidney
T3	Tumour extends into major veins or perinephric tissues but not into the ipsilateral adrenal gland and not beyond Gerota fascia
T3a	Tumour grossly extends into the renal vein or its segmental branches, or tumour invades perirenal and/or renal sinus fat but not beyond Gerota fascia
T3b	Tumour grossly extends into the vena cava below the diaphragm
T3c	Tumour grossly extends into the vena cava above the diaphragm or invades the wall of the vena cava
T4	Tumour invades beyond Gerota's fascia (including contiguous extension into the ipsilateral adrenal gland)
N-regional lymph nodes
Nx	Regional nodes cannot be assessed
N0	No regional lymph nodes metastases
N1	Metastases in a single regional lymph node
N2	Metastases in more than 1 regional lymph node
M-distant metastases
M0	No distant metastases
M1	Distant metastases
TNM stage grouping
Stage I	T1	N0	M0
Stage II	T2	N0	M0
Stage III	T3	N0	M0
	T1,T2,T3	N1	M0
Stage IV	T4	Any N	M0
	Any T	N2	M0
	Any T	Any N	M1

TNM: Tumor, node, metastasis.