Neurological improvement of perineural and leptomeningeal spread of squamous cell carcinoma treated with intrathecal chemotherapy and systemic EGFR inhibition.

Squamous cell carcinoma (SCC) is a common cancer of the skin. Risk factors include fair skin, excessive sun and ultraviolet light exposure, and history of xeroderma pigmentosa. Perineural invasion (PNI), an uncommon manifestation of SCC, involves microscopic tumor cells invading various layers of the nerve sheath. It is associated with a poorer prognosis. Standard treatment for PNI includes radiation therapy. Here, we describe a case an older gentleman with a history of SCC with PNI successfully treated with erlotinib and intrathecal chemotherapy.