Note: Site-Specific Factors 3-6 are used to code the presence or absence of lymph node involvement in each of 7 different levels and other groups defined by AJCC. The definitions of the levels are the same for all applicable head and neck sites. One digit is used to represent lymph nodes of a single level, with the three digits of Site-Specific Factor 3 representing lymph nodes of, respectively, Levels I-III; the digits of Site-Specific Factor 4 representing lymph nodes of Levels IV and V and the retropharyngeal nodes; the digits of Site-Specific Factor 5 representing lymph nodes of Levels VI and VII and the facial nodes; and the digits of Site-Specific Factor 6 representing the remaining Other groups as defined by AJCC. In each digit, a code 1 means Yes, the nodes are involved.
Code | Description |
---|---|
000 | No lymph node involvement in Levels IV or V or retropharyngeal |
100 | Level IV lymph node(s) involved |
010 | Level V lymph node(s) involved |
001 | Retropharyngeal nodes involved |
110 | Level IV and V lymph nodes involved |
101 | Level IV and retropharyngeal nodes involved |
011 | Level V and retropharyngeal nodes involved |
111 | Level IV and V and retropharyngeal lymph nodes involved |
999 | Unknown if regional lymph node(s) involved, not stated Regional lymph node(s) cannot be assessed Not documented in patient record |