MALIGNANT PERIPHERAL NERVE SHEATH TUMOR: A BRAZILIAN COLLABORATIVE STUDY OF 4 CASES

Abstract

Objective Malignant peripheral nerve sheath tumor (MPNST) is an extremely rare malignancy in the oral cavity. It is derived from peripheral nerves and can display the differentiation of nerve sheath elements. This study investigated the frequency of MPNST that has been submitted for microscopic examination from 2 Brazilian oral and maxillofacial pathology services. Study Design A retrospective study was conducted on biopsies obtained from 1954 to April 2018 at 2 Brazilian oral and maxillofacial pathology services. A total of 43,915 biopsy specimens were analyzed. Demographic data and histopathologic diagnosis were evaluated descriptively. Results A total of 4 cases of MPNST were surveyed, representing 0.009% of the oral lesions at the centers studied. MPNST was diagnosed in 3 males and 1 female. The mean age ± SD was 37.7 ± 15.9 (range 16-61) years. Two of the 4 lesions occurred in the maxilla and the mean of evolution time was 10.2 months. Immunohistochemical analysis revealed positivity of neoplasms cells for S-100, vimentin, and glial fibrillary acidic protein (GFAP). Conclusions This study has contributed to the improvement of the epidemiology, prognostic markers, and outcomes of this malignancy. The differential diagnosis of the MPNST may be facilitated by additional information obtained from immunohistochemistry findings. Support: FAPEMIG.