A specimen out of the blue, case of squamous cell carcinoma demonstrating various patterns of perineural Invasion

Abstract

Oral squamous cell carcinoma (OSCC) is the fifth most frequent cancer in the world and about 3% of all malignant neoplasms are usually spread by lymphatic or rarely hematogenous spread. Perineural invasion (PNI) is an alternate method of tumor spread and an important prognostic factor for further treatment plans in OSCC. The patterns of PNI are categorized, according to various research articles and studies conducted, some of the common ones are complete encirclement, incomplete “crescent-like” encirclement, sandwiching, onion skin, partial invasion, and neural permeation. We received a hemiglossectomy specimen of a 62-year-old male diagnosed with squamous cell carcinoma (SCC) on a small biopsy with an ulceroproliferative lesion in the left lateral border of tongue. Microscopy showed an invasive tumor showing features of well-differentiated SCC with extensive various patterns of PNI such as complete encirclement, incomplete encirclement, sandwich pattern, onion skinning, crescenting and neural permeation. PNI indicates and predicts the local recurrence and also regional nodal metastasis in patients with OSCC. PNI should be searched and included in the histopathology report in every OSCC case including recurrent cases.