Focal melanocytic lesions of the oral mucosa: An epidemiological and morphological study

This study aimed to analyse the clinical and histopathological characteristics of focal oral melanocytic lesions in a Brazilian reference service in Oral and Maxillofacial Pathology.

A cross-sectional study was conducted over an 18-year period. Demographic data and clinical features were collected from the archives, and all biopsy specimens diagnosed as oral melanocytic lesions were retrieved and reviewed.

We identified 339 melanocytic lesions. Of these, 191 were melanotic macules, 112 melanocytic nevi, 14 mucosal lentigo simplex, 12 melanomas, 9 solar lentigos, and 1 melanoacanthoma. Lesions occurred mostly in white-skinned (74.2%) women (65.2%). The main reported clinical aspect was the macule (67.4%), and the most affected site was the lip vermilion (25.4%), followed by the palate (22.9%). Melanomas were larger in size and were observed in older patients with an overall shorter time of onset. The most frequent subtypes of melanocytic nevi were intramucosal (44.6%), compound (24.1%), and blue nevus (20.5%). They showed a heterogeneous architectural pattern with the presence of the three cell types.

The most frequent lesions are melanotic macule and nevus, especially the intramucosal subtype. Patients are usually white-skinned women presenting a small, long-lasting, macular lesion on the lip vermilion or palate.