| Primary Tumor (T) | |
| Regional Lymph Nodes (N) | |
| Distant Metastasis (M) | |
This view displays the TNM formula. Please select appropriate value from the list for T/N/M variables. The result will be displayed, based on your selection of variables.
Definition of Primary Tumor (T)
| T Category | T Criteria |
|---|---|
| TX | Primary tumor cannot be assessed |
| Tis | Carcinoma in situ |
| T1 | Tumor smaller than or equal to 2 cm in greatest dimension |
| T2 | Tumor larger than 2 cm, but smaller than or equal to 4 cm in greatest dimension |
| T3 | Tumor larger than 4 cm in maximum dimension or minor bone erosion or perineural invasion or deep invasion |
| T4 | Tumor with gross cortical bone/marrow, skull base invasion and/or skull base foramen invasion |
| T4a | Tumor with gross cortical bone/marrow invasion |
| T4b | Tumor with skull base invasion and/or skull base foramen involvement |
Deep invasion is defined as invasion beyond the subcutaneous fat or greater than 6 mm (as measured from the granular layer of adjacent normal epidermis to the base of the tumor); perineural invasion for T3 classification is defined as tumor cells within the nerve sheath of a nerve lying deeper than the dermis or measuring 0.1 mm or larger in caliber, or presenting with clinical or radiographic involvement of named nerves without skull base invasion or transgression.
Definition of Regional Lymph Node (N)
Clinical N (cN)| N Category | N Criteria |
|---|---|
| NX | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension and ENE(-) |
| N2 | Metastasis in a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-); or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-); or in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-) |
| N2a | Metastasis in a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-) |
| N2b | Metastases in multiple ipsilateral nodes, none larger than 6 cm in greatest dimension and ENE(-) |
| N2c | Metastases in bilateral or contralateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-) |
| N3 | Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-); or metastasis in any node(s) and clinically overt ENE [ENE(+)] |
| N3a | Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-) |
| N3b | Metastasis in any node(s) and ENE(+) |
A designation of “U” or “L” may be used for any N category to indicate metastasis above the lower border of the cricoid (U) or below the lower border of the cricoid (L). Similarly, clinical and pathological ENE should be recorded as ENE(-) or ENE(+).
| N Category | N Criteria |
|---|---|
| NX | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension and ENE(-) |
| N2 | Metastasis in a single ipsilateral lymph node, 3 cm or smaller in greatest dimension and ENE(+); or larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-); or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm in greatest dimension and ENE(-); or in bilateral or contralateral lymph node(s), none larger than 6 cm in greatest dimension, ENE(-) |
| N2a | Metastasis in single ipsilateral node 3 cm or smaller in greatest dimension and ENE(+); or a single ipsilateral node larger than 3 cm but not larger than 6 cm in greatest dimension and ENE(-) |
| N2b | Metastases in multiple ipsilateral nodes, none larger than 6 cm in greatest dimension and ENE(-) |
| N2c | Metastases in bilateral or contralateral lymph node(s), none larger than 6 cm in greatest dimension and ENE(-) |
| N3 | Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-); or in a single ipsilateral node larger than 3 cm in greatest dimension and ENE(+); or multiple ipsilateral, contralateral, or bilateral nodes, any with ENE(+); or a single contralateral node of any size and ENE(+) |
| N3a | Metastasis in a lymph node larger than 6 cm in greatest dimension and ENE(-) |
| N3b | Metastasis in a single ipsilateral node larger than 3 cm in greatest dimension and ENE(+); or multiple ipsilateral, contralateral, or bilateral nodes, any with ENE(+); or a single contralateral node of any size and ENE(+) |
A designation of “U” or “L” may be used for any N category to indicate metastasis above the lower border of the cricoid (U) or below the lower border of the cricoid (L). Similarly, clinical and pathological ENE should be recorded as ENE(-) or ENE(+).
Definition of Distant Metastasis (M)
| M Category | M Criteria |
|---|---|
| M0 | No distant metastasis |
| M1 | Microscopic evidence of distant metastasis |