Table A1.
AJCC (ed 7) Regional Lymph Node (N) Classification for Nasopharynx and Oropharynx/Hypopharynx Cancer
| Classification | Description by Cancer Type | |
|---|---|---|
| Nasopharynx Cancer | Oropharynx/Hypopharynx Cancer* | |
| NX | Regional lymph nodes cannot be assessed | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis | No regional lymph node metastasis |
| N1 | Unilateral metastasis in cervical lymph node(s), ≤ 6 cm in greatest dimension, above the supraclavicular fossa, and/or unilateral or bilateral, retropharyngeal lymph nodes, ≤ 6 cm in greatest dimension† | Metastasis in a single ipsilateral lymph node, ≤ 3 cm in greatest dimension |
| N2 | Bilateral metastasis in cervical lymph node(s), ≤ 6 cm in greatest dimension, above the supraclavicular fossa† | Metastasis in a single ipsilateral lymph node, > 3 cm but not > 6 cm in greatest dimension, or in multiple ipsilateral lymph nodes, none > 6 cm in greatest dimension, or in bilateral or contralateral lymph nodes, none > 6 cm in greatest dimension |
| N2a | Not specified | Metastasis in a single ipsilateral lymph node > 3 cm but not > 6 cm in greatest dimension |
| N2b | Not specified | Metastasis in multiple ipsilateral lymph nodes, none > 6 cm in greatest dimension |
| N2c | Not specified | Metastasis in bilateral or contralateral lymph nodes, none > 6 cm in greatest dimension |
| N3 | Metastasis in a lymph node(s)† > 6 cm and/or to supraclavicular fossa | Metastasis in a lymph node > 6 cm in greatest dimension |
| N3a | > 6 cm in dimension | Not specified |
| N3b | Extension to the supraclavicular fossa‡ | Not specified |
NOTE. Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, IL. The original source for this information is the AJCC Cancer Staging Manual (ed 7), published in 2010 by Springer.18
Metastases at level VII are considered regional lymph node metastases, originally described by Ho (Ho JHC: IARC Scientific Publication 20, 1978, pp 99–113). It is defined by three points: the superior margin of the sternal end of the clavicle, the superior margin of the lateral end of the clavicle, and the point where the neck meets the shoulder. Note that this definition would include caudal portions of levels IV and VB. All cases with lymph nodes (whole or part) in the fossa were considered N3b.
Midline nodes are considered ipsilateral nodes.
Supraclavicular zone or fossa is relevant to the staging of nasopharyngeal carcinoma and is the triangular region.