Squamous and basal cell carcinoma with perineural invasion: pathophysiology and presentations

Squamous and basal cell carcinomas with perineural invasion are typically difficult to treat because of their propensity to metastasize, their aggressive nature, and the concept of skip lesions. Perineural invasion is an under-recognized and underdiagnosed condition even though the literature points to its high rate of incidence in squamous cell carcinoma and a nonnegligible incidence rate in basal cell carcinoma. Perineural invasion has been linked to higher recurrence rates and poorer prognosis. This review has been written to aid clinicians in identifying and managing the condition as early as possible by describing the clinical and microscopic manifestations of perineural invasion.