Perineural Invasion of Oral Squamous Cell Carcinoma: A New Hurdle for Surgeons.

The high rate of mortality associated with cancer is due to its inherent nature to metastasize. Perineural invasion (PNI) is a relatively rare mode of metastasis, and a distinct pathologic entity that can be observed in the absence of lymphatic or vascular invasion which is still shrouded by mystery. PNI is a marker of poor prognosis. Despite increasing recognition of this metastatic process, there has been little progress in the understanding of mechanisms behind PNI. The purpose of this article is to make surgeons aware of caudad to cephalad metastasis of oral cancer along trigeminal nerve.