<b>Tumor grade (G)</b> [assigned by the pathologist. Also called histological grade.] 
GX: Grade cannot be assessed
G1: Well differentiated 
G2: Moderately differentiated
G3: Poorly differentiated 
G4: Undifferentiated 

<b>Primary tumor (T)</b> 
TX: Primary tumor cannot be assessed 
T0: No evidence of primary tumor 
T1: Tumor 5 cm or less in greatest dimension 
T1a: Superficial tumor 
T1b: Deep tumor 
T2: Tumor more than 5 cm in greatest dimension
T2a: Superficial tumor 
T2b: Deep tumor Note: Superficial tumor is located exclusively above the superficial fascia without invasion of the fascia; deep tumor is located either exclusively beneath the superficial fascia, or superficial to the fascia with invasion of or through the fascia, or superficial and beneath the fascia. Retroperitoneal, mediastinal, and pelvic sarcomas are classified as deep tumors. 

<b>Regional lymph nodes (N)</b> 
NX: Regional lymph nodes cannot be assessed 
N0: No regional lymph node metastasis 
N1: Regional lymph node metastasis 

<b>Distant metastasis (M)</b>
MX: Distant metastasis cannot be assessed 
M0: No distant metastasis 
M1: Distant metastasis