Oral cavity,  oropharynx                               Nasopharynx,  hypopharynx,  larynx
(tumor can be seen directly)                                     (tumor cannot be seen directly)

Tx       Tumor cannot be measured
T0       No evidence of primary tumors
Tis       Carcinoma in situ
T1       Tumor no larger than 2cm(3/4in.)         Tumor confined to one site
T2       Tumor 2-4cm(3/4-1 1/2in.)                  Involves more than one site at origin
T3       Tumor over 4cm(1 1/2in.)                   Tumor extends beyond primary site
T4       Massive tumor,  over 4cm(1 1/2in.)
           with extension to adjacent structures