Table 1.
TNM Classification.
| Tumor (T) | |
| T1 | ≤2 cm tumor size |
| T2 | >2 cm but no more than 5 cm |
| T3 | >5 cm |
| T4 | invasion of bone, muscle, fascia or cartilage |
| Nodal (N) | |
| cN0 | node negative by clinical exam (clinical or imaging exam) |
| pN0 | node negative by pathologic exam |
| N1 | metastasis in regional node |
| N1a | micrometastasis (sentinel node or elective lymphadenectomy) |
| N1b | macrometastasis (clinically detectable, confirmed by surgery or fine-needle aspiration) |
| N2 | in-transit metastasis |
| Metastasis (M) | |
| M0 | no distant metastasis |
| M1 | metastasis beyond regional lymph nodes |
| M1a | metastasis to skin, subcutaneous tissues or distant lymph nodes |
| M1b | metastasis to lung |
| M1c | metastasis to all other visceral sites |