| T1 | Tumor localized to the nasal cavity and paranasal sinuses with a space between tumor and lamina cribosa |
| T2 | Tumor developed in nasal cavity or sinuses but in contact with cribriform lamina and/or sphenoid extension |
| T3 | Tumor with intracranial extradural and/or orbital expansion |
| T4 | Tumor with intracranial intradural extension |
| N0 | No metastatic cervical nodes |
| N1 | Metastatic cervical nodes |
| M0 | No distant metastases |
| M1 | Distant metastases |