Table 1. Primary Tumor (T)a
| TX | Primary tumor cannot be assessed. |
| T0 | No evidence of primary tumor. |
| Tis | Carcinoma in situ. |
| T1 | Tumor confined to the nasopharynx, or tumor extends to oropharynx and/or nasal cavity without parapharyngeal extension.b |
| T2 | Tumor with parapharyngeal extension.b |
| T3 | Tumor involves bony structures of skull base and/or paranasal sinuses. |
| T4 | Tumor with intracranial extension and/or involvement of cranial nerves, hypopharynx, orbit, or with extension to the infratemporal fossa/masticator space. |
| aReprinted with permission from AJCC: Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 41-56. |
| bParapharyngeal extension denotes posterolateral infiltration of tumor. |
