Version July 2025
| Region boundaries | Node groups* | |
| N1: Anterior region | Superior: lower border of cricoid cartilage Lateral (neck): medial border of carotid sheaths Lateral (chest): mediastinal pleura Anterior: sternum Posterior (medially): great vessels, pericardium Posterior (laterally): phrenic nerve Inferior: xiphoid, diaphragm | Low anterior cervical: peritracheal, peri-thyroid (AAO-HNS/ASHNS level 6/IASLC level 1) |
| Peri-thymic | ||
| Prevascular (IASLC level 3a) | ||
| Para-aortic, ascending aorta, superior phrenic (IASLC level 6) | ||
| Supradiaphragmatic/inferior phrenic/pericardial | ||
| N2: Deep region | Superior: lower border of cricoid cartilage Anteromedial (neck): lateral border of sternohyoid, medial border of carotid sheath Posterolateral (neck): anterior border of trapezius Anterior (chest): right – anterior border of SVC; left – aortic arch, aortopulmonary window Posterior (chest): esophagus Lateral (chest): pulmonary hila Inferior: diaphragm | Perijugular (AAO-HNS/ASHNS level 4) |
| Supraclavicular/venous angle: confluence of internal jugular & subclavian vein (AAO-HNS/ASHNS level 5b) | ||
| Internal mammary nodes | ||
| Upper paratracheal (IASLC station 2) | ||
| Lower paratracheal (IASLC station 4) | ||
| Subaortic/aortopulmonary window (IASLC station 5) | ||
| Subcarinal (IASLC station 7) | ||
| Hilar (IASLC station 10) |
AAO-HNS/ASHNS: American Academy of Otolaryngology-Head and Neck Surgery, American Society for Head and Neck Surgery; AJCC: American Joint Committee on Cancer; IASLC: International Association for the Study of Lung Cancer; SVC: superior vena cava.
* Region and node group boundaries match those established by the AAO-HNS/ASHNS, and the IASLC where applicable.
