Perineural invasion of head and neck skin cancer: diagnostic and therapeutic implications.

Perineural invasion of head and neck skin cancer is a poorly understood and often misdiagnosed pathological entity. Incidental or microscopic perineural invasion is identified by the pathologist and often leads to confusion as to how the patient should be further treated. The less common but more aggressive clinical perineural spread presents with a clinical deficit, which is too commonly misinterpreted by the clinician. This review will try to clarify the terminology that exists in the literature and explore the mechanisms of invasion and spread. It will look at the recent advances in diagnosis and comment on the limitations inherent in current classification schemes. A review of outcomes will be included and current treatment strategies utilized discussed.