Original Contributions Clinicopathologic analysis of 7 cases of oral schwannoma and review of the literature ☆ Pedro Paulo de Andrade Santos, DDS, MSc, Valéria Souza Freitas, DDS, MSc, Leão Pereira Pinto, DDS, PhD, Roseana de Almeida Freitas, DDS, PhD, Lélia Batista de Souza, DDS, PhD ⁎ Postgraduation Program in Oral Pathology, Federal University of Rio Grande do Norte, Natal, RN, Brazil Abstract Schwannomas, also known as neurilemmomas, are uncommon neoplasms apparently derived from Schwann cells. The growth of these tumors causes displacement and compression of the nerve of origin. Schwannomas are usually solitary lesions but can be multiple when associated with neurofibromatosis. Anti-S100 protein is the most widely used antibody for the identification of this neoplasm. Surgical excision is the treatment of choice for schwannomas, with few and controversial reports of recurrence or malignant transformation. The present article reports 7 additional cases of oral schwannoma, and the literature is reviewed regarding clinicopathologic features, immunohis- tochemical findings, differential diagnosis, and therapeutic management of this benign neural tumor. Crown Copyright © 2010 Published by Elsevier Inc. All rights reserved. Keywords: Neurilemmoma; Schwannoma; Neural tumor; Benign tumor 1. Introduction Schwannomas are benign, slow-growing, epineurium- encapsulated neoplasms arising from Schwann cells that comprise the myelin sheaths surrounding peripheral nerves [1]. Schwannomas show 2 histologic patterns: Antoni type A and Antoni type B. Although these tumors may affect any site of the body, 25% to 48% of these lesions are found in the head and neck region [2,3]. Schwannomas of the head and neck occur both intracranially, mainly at the cerebellar pontine angle, and in peripheral soft tissues, mainly the tongue followed by the palate, floor of mouth, oral mucosa, and mandible [4]. Schwannomas involving soft tissues appear as a smooth submucosal swelling, resembling other lesions such as mucocele, fibroepithelial polyp, fibroma, lipoma, and benign salivary gland tumors [5]. Normally, schwannomas are slow-growing tumors that might be present for some years before becoming symp- tomatic. Swelling is the most common symptom, followed by paresthesia [6]. Over time, schwannomas may grow to large proportions, with their increase in size probably being associated with intralesional hemorrhage [7]. Conservative surgical removal is the treatment of choice, with wide excision not being recommended. If complete enucleation is achieved, no recurrence should be expected [8]. The present article reports 7 additional cases of schwa- nnoma, all of them involving the oral cavity, and the literature is reviewed regarding peculiar clinicopathologic features, immunohistochemical findings, differential diag- nosis, and therapeutic management of this tumor. 2. Case report 2.1. Case 1 A 41-year-old woman was referred to our department for evaluation of a painless, smooth, pinkish nodule located in the right posterior region of the hard palate. The nodule had been noted by the patient 5 years earlier. The patient's medical history was unremarkable. An excisional biopsy was performed based on the initial clinical diagnosis of Available online at www.sciencedirect.com Annals of Diagnostic Pathology 14 (2010) 235 – 239 ☆ Conflict of interest: The authors declare no conflict of interest. ⁎ Corresponding author. Departamento de Odontologia, Universidade Federal do Rio Grande do Norte, Natal, RN 59056-000, Brazil. Tel.: +55 84 3215 4138; fax: +55 84 3215 4138. E-mail address: leliasouza@dod.ufrn.br (L.B. de Souza). 1092-9134/$ – see front matter. Crown Copyright © 2010 Published by Elsevier Inc. All rights reserved. doi:10.1016/j.anndiagpath.2010.02.009