| cNX |
Regional lymph nodes cannot be assessed (for example, previously removed) |
| cN0 |
No regional lymph node metastases |
| cN1 |
Metastases to movable ipsilateral level I, II axillary lymph node(s) |
| cN2 |
Metastases in ipsilateral level I, II axillary lymph nodes that are clinically fixed or matted; or in clinically detected ipsilateral internal mammary nodes in absence of clinically evident axillary lymph node metastases |
| cN2a |
Metastases in ipsilateral level I, II axillary lymph nodes fixed to one another (matted) or to other structures |
| cN2b |
Metastases only in clinically detected ipsilateral internal mammary nodes and in absence of clinically evident level I, II axillary lymph node metastases |
| cN3 |
Metastases in ipsilateral infraclavicular (level III axillary) lymph node(s) with or without level I, II axillary lymph node involvement; or in clinically detected ipsilateral internal mammary lymph node(s) with clinically evident level I, II axillary lymph node metastases; or metastases in ipsilateral supraclavicular lymph node(s) with or without axillary or internal mammary lymph node involvement |
| cN3a |
Metastases in ipsilateral infraclavicular lymph node(s) |
| cN3b |
Metastases in ipsilateral internal mammary lymph node(s) and axillary lymph node(s) |
| cN3c |
Metastases in ipsilateral supraclavicular lymph node(s) |
