Table 1.
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].