TNM characteristics in lung cancer. Mountain CF, Chest 1997;111:1712-1717
Lung cancer TNM classification, Table 1.
| Primary tumour (T) | |
| TX | Primary tumour cannot be assessed, or tumour proven by the presence of malignant cells in sputum or bronchial washings but not visualized by imaging or bronchoscopy |
| T0 | No evidence of primary tumour |
| T1 | Tumour £ 3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than the lobar bronchus (i.e. not in the main bronchus) |
| T2 | Tumour with any of the following features of size or extent: |
| - > 3 cm in greatest dimension |
| - involves main bronchus, ³ 2 cm distal to the carina |
| - invades the visceral pleura |
| - associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung |
| T3 | Tumour of any size that directly invades any of the following: chest wall (including superior sulcus tumours), diaphagm, mediastinal pleura, parietal pericardium; or tumour in the main bronchus < 2 cm distal to the carina, but without involvement of the carina; or tumour associated with atelectasis or obstructive pneumonitis of the entire lung |
| T4 | Tumour of any size with invasion of the mediastinum involving heart, great vessels, trachea, oesophagus, vertebral body or carina, or presence of malignant pleural effusion (cytologically positive), or satellite tumoural nodules within the lobe containing the primary tumour. |
| Regional lymph nodes (N) | |
| NX | Regional lymph nodes cannot be assessed |
| N0 | No regional lymph node metastasis |
| N1 | Metastasis of ipsilateral peribronchial and/or ipsilateral hilar lymph nodes, and intrapulmonary nodes involved by direct extension of the primary tumour |
| N2 | Metastasis to ipsilateral mediastinal and/or subcarinal lymph node(s) |
| N3 | Metastasis to contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s) |
| Distant metastasis (M) | |
| MX | Presence of distant metastasis cannot be assessed |
| M0 | No distant metastasis |
| M1 | Distant metastasis present |