A 38-year review of oral schwannomas and neurofibromas in a Brazilian population: clinical, histopathological and immunohistochemical study.

The benign peripheral nerve sheath tumours are rare lesions mainly represented by schwannoma and neurofibroma. The present work evaluated the clinical and histopathological features of schwannomas and neurofibromas of the oral cavity diagnosed in a Brazilian population. Among 9.000 cases of oral lesions archived from 1970 to 2008, four schwannomas and 12 neurofibromas were identified, microscopically revised and immunohistochemically certified through a panel including monoclonal antibodies (anti-S100, vimentin, HHF-35 and desmin). From biopsy and histological sections records, clinical and histopathological data were retrieved, reviewed and statistically analysed. Predominantly, schwannomas affected non-white males (3:1), with an age and size averages of 34.7 years and 2.8 cm, respectively. Neurofibromas preferentially occurred on the gingival/alveolar ridge of white females (5:1), with 35.7-year mean age, peak of incidence between 3rd and 5th decade, and size average of 1.7 cm. (12 cases, 75%). The studied tumours exhibited more frequently as a painless, sessile and slow growth very similar to other oral lesions, but their microscopic features differed significantly. Schwannomas and neurofibromas are extremely uncommon in the oral cavity, exhibiting clinical features very similar but specific and peculiar microscopic findings that are useful in the establishment of the diagnosis, which in some particular cases must be confirmed by immunohistochemistry.