Palisaded Encapsulated Neuroma of the Lingual Mandibular Gingiva: A Case Report

Palisaded encapsulated neuroma (PEN) is a rare benign neural tumor, often localized on faces and sometimes observed in a striking predilection on the skin of the face. This tumor might also occur in oral cavity, especially on the tongue. Some researchers have speculated that PEN is hamartomatosis, and there is a possible role of frequent trauma in its etiology.
Case Report: Our case was a 27-year-old female with a painless flat swell in the right lingual mandibular gingiva. This lesion was formed about a year ago without any radiographic appearance. Fibroma and lipoma were included in the differential diagnosis of the lesion. Benign spindle cell tumor was reported in this reported according to histopathological examination results. Afterwards, immunohistochemical and silver stains were performed on desmin, S100, alpha-smooth muscle actin (α-SMA) and neuron-specific enolase markers for definitive diagnosis. The final diagnosis was PEN due to positive staining for S100 and NSE, as well as positive silver staining.
According to the results, accurate diagnosis of PEN and differentiating it from other spindle cell tumors could help in the selection of the best treatment and prevention of unnecessary procedures.