An unusual localization of intraosseus Schwannoma: mandibular localization and new pathogenetic prospectives

AIM: The aim of the study is to give an explanation on the Intra-osseous Schwanoma etio-pathogenesis, based on the isto-pathological findings presented by the Authors. MATERIAL OF STUDY: In a 40 years old patient with pain on the territory innervated by the third right trigeminal branch, OPT showed a like ground-glass area that involved the mandible with the mandibular canal disappearance and dental roots resorption. They removed the lesion with preservation of the vascular-neural beam on which the lesion were extremely attached; the histological examination confirmed the diagnosis of intra-osseous Schwannoma. Immunohistochemically the Schwannoma labelled with antibodies to S-100, Vimentin, Osteopontin and Osteonectin. RESULST: The clinical and radiological follow-up after one year since the surgery, using OPT showed an improvement of bone formation and the disappearance of the pain. DIscussioN: Schwannoma rarely presents as an intraosseous mass, comprising less than 1% of all bone tumors with a strong predilection for the mandible. Data like the expression of osteopontin are believed to be distinctive feature of other schwannian cell tumors such as the granular cell tumor. Such data might explain the prevalence of mandibular location among the rare intraosseous schwannomas and might point out that the calcified shwannoma of the skull is similar to an hamartomatous lesion.