Clinicopathological features of melanotic and non-melanotic oncocytic lesions of the nasopharynx.

Oncocytic metaplastic lesions of the nasopharynx are rare benign entities which are divided into melanotic and non-melanotic forms. Less than 40 non-melanotic and 30 melanotic cases have been reported in the literature. We present the largest known case series to date of melanotic oncocytic metaplasia and more than 20 cases of non-melanotic oncocytic metaplasia. Clinical, endoscopic, histological and immunohistochemical features were reviewed. Most cases presented in males starting from their late adulthood. Compared to its non-melanotic counterpart, all cases of melanotic oncocytic metaplasia had a smoking history (p=0.041). All cases of melanotic oncocytic metaplasia were negative to melanocytic markers (S100, HMB-45, Melan-A and MiTF). Although no disease-related mortality was recorded, concurrent melanoma and nasopharyngeal carcinoma were seen in two cases.