Table 1 TNM staging system for oral cavity
Primary tumor (T) | |
|---|---|
T1 | Tumor ≤2 cm in greatest dimension |
T2 | Tumor >2 cm and ≤4 cm in greatest dimension |
T3 | Tumor >4 cm in greatest dimension |
T4a | Moderately advanced local disease. Tumor invades adjacent structures only (through cortical bone [mandible or maxilla], into deep [extrinsic] muscle of tongue, maxillary sinus, skin of face) |
T4b | Very advanced local disease. Tumor invades masticator space, pterygoid plates, or skull base and/or encases internal carotid artery |
Regional Lymph Nodes (N) | |
N1 | Metastasis in a single ipsilateral lymph-node, ≤3 cm in greatest dimension |
N2a | Metastasis in a single ipsilateral lymph-node, >3 cm and ≤6 cm in greatest dimension |
N2b | Metastasis in multiple ipsilateral lymph-nodes, none >6 cm in greatest dimension |
N2c | Metastasis in bilateral or controlateral lymph-nodes, none >6 cm in greatest dimension |
N3 | Metastasis in lymph-nodes >6 cm in greatest dimension |
Distant metastasis (M) | |
M1 | Distant metastasis |