Table 2. Regional Lymph Nodes (N)a
| NX | Patients in whom the regional nodes cannot be assessed (e.g., previously removed for another reason). |
| N0 | No regional metastases detected. |
| N1–3 | Regional metastases based upon the number of metastatic nodes and presence or absence of intralymphatic metastases (in transit or satellite metastases). |
| Note: N1–3 and a–c subcategories assigned as shown below: |
| N Classification | No. of Metastatic Nodes | Nodal Metastatic Mass |
| N1 | 1 | a: micrometastasis.b |
| b: macrometastasis.c |
| N2 | 2–3 | a: micrometastasis.b |
| b: macrometastasis.c |
| c: in transit met(s)/satellites(s) without metastatic nodes. |
| N3 | ≥4 metastatic nodes, or matted nodes, or in transit met(s)/satellite(s) with metastatic node(s). | |
| No = number. |
| aReprinted with permission from AJCC: Melanoma of the skin. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 325-44. |
| bMicrometastases are diagnosed after sentinel lymph node biopsy and completion lymphadenectomy (if performed). |
| cMacrometastases are defined as clinically detectable nodal metastases confirmed by therapeutic lymphadenectomy or when nodal metastasis exhibits gross extracapsular extension. |
