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Head & Neck Staging: Table Five
| TNM Classification | Histological/Clinical Features |
|---|---|
| T1 | 2 cm or less without extraparenchymal extension |
| T2 | >2cm but <4cm without extraparenchymal extension |
| T3 | >4cm and/or extraparenchymal extension |
| T4a | Invades skin, mandible, ear canal, and/or facial nerve |
| T4b | Invades skull base and/or pterygoid plates and/or encases carotid artery |
| TNM Classification | Histological/Clinical Features |
|---|---|
| T1 | 2cm or less limited to thyroid |
| T2 | >2cm but <4cm limited to thyroid |
| T3 | >4cm limited to thyroid or any tumor with minimal extrathyroid extension |
| T4a | Extending beyond thyroid capsule to invade subcutaneous soft tissue, larynx, trachea, esophagus or recurrent laryngeal nerve |
| T4b | Invades prevertebral fascia or encases carotid artery or mediastinal vessels |