Table 1: High risk factors for NMSC tumor characteristics*.

Histologic differentiation
 Poor differentiation
 Spindle cell characteristics
 Necrosis
 High mitotic activity
 Deep invasion
Depth of invasion
 >2 mm
 Clark level 3IV
Perineural invasion
High risk anatomic sites
 Nonglabrous Lip
 Ear
Advanced T stage (T3 and T4)
 Bony extension or involvement
 Maxilla, mandible, orbit, temporal bone
 Perineural invasion
 Invasion of skull base
 Invasion of axial or appendicular skeleton

*7th Edition of American Joint Commission on Cancer Staging Manual [18].