Intraoral Pseudo-Onion Bulb Intraneural Proliferations in a Patient with Hemimandibular Hyperplasia: A Case Report and Review of the Literature

Abstract

This report and review of the literature describes a case of benign intraoral lesions of perineurial origin in a patient with symptomatic hemimandibular hyperplasia causing partial denture soreness. Perineuriomas are a benign peripheral nerve sheath tumor composed of perineurial cells. Intraoral perineuriomas are an extremely rare entity. Two main types of perineuriomas have been described: intraneural and extraneural perineuriomas. A third, similar entity, called an intraneural pseudoperineuriomatous proliferation, has recently been proposed in the literature as a separate and distinctive diagnosis. This report describes the histologic and clinical presentation of intraneural pseudoperineuriomatous proliferations in a patient with hemimandibular hyperplasia.

Orofacial overgrowth with peripheral nerve enlargement and perineuriomatous pseudo-onion bulb proliferations is part of the PIK3CA-related overgrowth spectrum

“…Vargo et al. 17 reported an individual with asymmetric mandibular enlargement, including enlargement of the mandibular canal, ipsilateral mandibular condyle enlargement, exostoses, and multiple fibrotic lesions on the tongue, shown to be POP on histologic evaluation. Siponen et al.…”