Cheek Numbness Caused by Perineural Tumor Invasion of the Infraorbital Nerve: A Review of 3 Diagnostically Challenging Cases.

BACKGROUND Facial pain and numbness are common symptoms with a variety of causes; rarely, it is an initial sign of perineural infiltration of malignant tumors. CASE REPORT Here, we report 3 challenging cases, all presenting with pain and numbness of the cheek as the primary symptoms. Upon referral, there were neither signs of severe illness nor information about previous malignant diseases, while the diagnostic work-ups revealed additional involvement of the facial nerve in 2 of the cases. Surgical removal of the perineural tissue around the infraorbital nerve revealed perineural invasion by a squamous carcinoma. A more thorough review of their medical histories revealed that all 3 of the patients had had previous facial skin cancer. CONCLUSIONS Numbness or pain in the cheek may represent perineural invasion of a facial cutaneous carcinoma. This review of 3 cases addresses the necessity of identifying previous incidences of skin cancer in the medical history.