Know your anatomy: perineural involvement of basal and squamous cell carcinoma on the face.

Knowledge of facial anatomy, particularly innervation, is basic to performing dermatologic surgery. There are clinical implications for cutaneous oncology (tumor spread), anesthesia, and postoperative complications, such as motor or sensory deficits. Perineural invasion of the facial nerves by squamous and basal cell carcinomas (SCCs and BCCs) occurs occasionally. We present three representative cases of both sensory and motor nerve involvement by SCC and BCC. The anatomy of the nerve supply of the face is summarized and the literature on perineural invasion by SCC and BCC is reviewed.