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

Abstract

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.

Clinical, Pathological, And Immunohistochemical Analysis Of Schwannoma In Oral Cavity: A Case Report

“…10 The immunohistochemical tests show that the schwannoma cells are positive for S-100 protein ( Figure 2E) and vimentin ( Figure 2F), which is associated with the benign tumor of peripheral nerve. 3,20 The S-100 protein normally appears in cells derived from the neural crest (Schwann cells, melanocytes, and glial cells). 21 Several members of the S-100 protein family are useful as markers for certain tumors and for epidermal differentiation.…”

“…10 Las pruebas inmunohistoquímicas muestran que las células del schwannoma son positivas para la proteína S-100 (Figura 2E) y para vimentina (Figura 2F), lo que se asocia con el tumor benigno de nervio periférico. 3,20 La proteína S-100 se presenta de forma normal en cé-lulas derivadas de la cresta neural (células de Schwann, melanocitos y células gliales). 21 Varios miembros de la familia de la proteína S-100 son útiles como marcadores para ciertos tumores y para la diferenciación epidérmica.…”

“…2 El schwannoma fue descrito por primera vez en 1910. 3 En la mayoría de los casos, el tumor inicia entre los 20 y 60 años de edad; 4 la tasa de incidencia mundial es de 1 a 20 casos por 1.000.000 de habitantes por año. 4 Cerca del 25 al 48% de los casos afecta la región de la cabeza y cuello; en la cavidad oral se observa principalmente en lengua, mucosa bucal y labio.…”

“…10 Las pruebas inmunohistoquímicas muestran que las células del schwannoma son positivas para la proteína S-100. 3 Otros marcadores celulares asociados a tumores neuronales son: E.N.E., vimentina, glycoprotein, SMA, desmin, and dimentin (leu-7). 11,12 In addition, the ki-67 protein as a marker allows determining cell proliferation.…”

“…10 The immunohistochemical tests show that the schwannoma cells are positive for protein S-100. 3 Other cellular markers associated with neuronal tumors are: E.N.E., vimentin,…”