Abstract
Tumors of the head and neck can spread by direct extension, hematogenous spread, or lymphatic dissemination. However, a process known as perineural invasion (PNI) allows nerves to act as a direct conduit for tumor growth away from the primary site. Perineural invasion is a rare, atypical presentation of cutaneous squamous cell carcinoma of the head and neck that affects about 2.5%-14% of the population. It is known to be associated with an increased risk of local recurrent and distant metastasis, thus adversely affecting the patient's prognosis. The majority of PNI cases are asymptomatic, often discovered during pathological evaluation. We report the case of a patient who presented with a 1-year history of right-sided face pain and symptoms suggestive of trigeminal facial neuralgia. A skin biopsy taken from a lesion on his right cheek showed PNI secondary to cutaneous squamous cell carcinoma of the head and neck. We treated the patient with radiotherapy and chemotherapy and his clinical condition improved significantly. We are publishing this case report to increase awareness of practicing physicians and nurses to PNI as an atypical presentation of squamous cell carcinoma that may affect selection of treatment modality and the patient's prognosis.