Retrospective analysis of oral peripheral nerve sheath tumors in Brazilians

Abstract

Traumatic neuroma, neurofibroma, neurilemmoma, palisaded encapsulated neuroma and malignant peripheral nerve sheath tumor (MPNST) are peripheral nerve sheath tumors and present neural origin. The goal of this study was to describe the epidemiological data of oral peripheral nerve sheath tumors in a sample of the Brazilian population. Biopsies requested from the Oral Pathology Service, School of Dentistry, Federal University of Minas Gerais (MG, Brazil), between 1966 and 2006 were evaluated. Lesions diagnosed as peripheral nerve sheath tumors were submitted to morphologic and to immunohistochemical analyses. All cases were immunopositive to the S-100 protein. Thirty-five oral peripheral nerve sheath tumors were found, representing 0.16% of all lesions archived in the Oral Pathology Service. Traumatic neuroma (15 cases) most frequently affected the mental foramen. Solitary neurofibroma (10 cases) was more frequently observed in the palate. Neurofibroma associated with neurofibromatosis type I (2 cases) was observed in the gingival and alveolar mucosa. Neurilemmoma (4 cases) was more commonly observed in the buccal mucosa. Malignant peripheral nerve sheath tumors (3 cases) occurred in the mandible, palate, and tongue. Palisaded encapsulated neuroma (1 case) occurred in the buccal mucosa. The data confirmed that oral peripheral nerve sheath tumors are uncommon in the oral region, with some lesions presenting a predilection for a specific gender or site. This study may be useful in clinical dentistry and oral pathology practice and may be used as baseline data regarding oral peripheral nerve sheath tumors in other populations.

Expression of S-100, EMA, CD34 and presence of mast cells in eight oral neurofibromas, and a review of 127 cases of the literature

“…The involvement of the oral cavity, as reported by Salla et al (28) and Chrysomali et al (5) , is rare. These reports are consistent with the findings of the present study, in which only 0.2% of the oral lesions reported over a period of 16 years were neurofibromas.…”

“…The prevalence of isolated oral neurofibromas (ONs) is uncertain; however, in patients with the syndrome, oral manifestations of the condition occur in up to 17% of patients (23) . Some studies indicate a slight female predominance for both the syndrome and isolated cases (5,7,23,28) , whereas others observe no distinction between the sexes (8) . Approximately 25% of neurofibromas are found in the head and neck region, and rare involvement of the oral cavity has been reported in sites such as the lips, tongue, buccal mucosa and alveolar ridge.…”

“…Along with schwannoma, it is one of the most common benign neoplasms of the neural sheath (2,13,28,36) . Neurofibromas can occur as solitary lesions or in association with multiple other neurofibromas of the skin, café-au-lait macules, freckling in the axillary and inguinal regions, Lisch nodules, and abnormalities of bone development as part of a syndrome known as neurofibromatosis type 1 (NF1) or von Recklinghausen disease (12,18,36) .…”

“…Approximately 25% of neurofibromas are found in the head and neck region, and rare involvement of the oral cavity has been reported in sites such as the lips, tongue, buccal mucosa and alveolar ridge. Neurofibromas usually present as a superficial, painless nodule with nonspecific clinical symptoms and resemble fibrous hyperplasia, fibromas, or lipomas (7,23,24,28) .…”

“…The rarity of oral cavity involvement in neurofibroma is reflected by the paucity of studies that exclusively consider this tumor and its intra-oral location, what generates problems regarding the epidemiological and immunohistochemical characterization of ONs (7,11,28,29) . The aim of this paper was to immunohistochemically characterize eight cases of neurofibromas located in the oral cavity using S-100, epithelial membrane antigen (EMA) and CD34 markers in addition to histochemical analyses using the modified Ziehl-Neelsen method.…”