Labial melanotic macule. B). Increased numbers of me lanocytes along Download Scientific Diagram Brown spots, especially on the lips, can be alarming to some. In some instances it can indicate rare oral mucosal melanoma, however in this case it was a non cancerous labial melanotic macule. Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review Oral Melanotic Macule MEDizzy