DYSPLASTIC MELANOCYTIC NEVUS IN THE ORAL CAVITY: MORPHOLOGIC AND IMMUNOHISTOCHEMICAL FINDINGS

A 35-year-old female patient attended the oral diagnostic service presenting with a lesion on the attached gingiva, in the region of dental elements 31 and 32. The lesion presented a red-blackish coloration, softened consistency, sessile implantation, and exophytic growth, measuring approximately 4 mm. An excisional biopsy was performed, and the diagnostic hypotheses of hemangioma and angiofibroma were considered. During microscopic examination, there was proliferation of nevus cells, organized in theques arrangements, exhibiting a certain degree of pleomorphism, hyperchromatism, and sometimes bizarre appearance. From the immunohistochemical analysis for HMB-45, Melan-A, S-100, and Ki-67 antibodies, the histopathologic diagnosis of dysplastic melanocytic nevus was given. This case emphasizes the importance of the association of clinical, histopathologic, and immunohistochemical characteristics to obtain an adequate diagnosis, to rule out any other lesions.