Head & Neck Staging: Table Four

Paranasal Sinuses (C30.0, C30.1)
TNM Classification	Histological/Clinical Features
TX	Primary tumor cannot be assessed
T0	No evidence of primary tumor
Tis	Carcinoma in situ

Maxillary Sinus
TNM Classification	Histological/Clinical Features
T1	Limited to maxillary sinus mucosa with no erosion or destruction of bone
T2	Causing bone erosion or destruction including extension into hard palate and/or middle nasal meatus, except extension to posterior wall of maxillary sinus and pterygoid plates
T3	Tumor invades any of the following: bone of the posterior wall of maxillary sinus, subcutaneous tissues, floor or medial wall of orbit, pterygoid fossa, ethmoid sinuses
T4a	Invades anterior orbital contents, skin of cheek, pterygoid plates, infratemporal fossa, cribiform plate, sphenoid or frontal sinuses
T4b	Invades any of the following: orbital apex, dura, brain, middle cranial fossa, cranial nerves other than maxillary division of trigeminal nerve (V2), nasopharynx, or clivus

Nasal Cavity and Ethmoid Sinus
TNM Classification	Histological/Clinical Features
T1	Confined to ethmoid with or without bone erosion
T2	Invading two sub sites in single region or extending to involve adjacent region within nasoethmoidal complex, with or without bony invasion
T3	Extends to invade medial wall or floor of orbit, maxillary sinus, palate, or cribiform plate
T4a	Invades any of the following: anterior orbital contents, skin of nose or cheek, minimal extension to anterior cranial fossa, pterygoid plates, sphenoid or frontal sinuses
T4b	Invades any of the following: orbital apex, dura, brain, middle cranial fossa, cranial nerves other than (V2), nasopharynx or clivus