COM Dec. 2011 Diagnosis UW School of Dentistry 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. What Caused These Multiple Hyperpigmented Macules of the Mouth? Pigmented Lesions of the Oral Cavity Oral and Maxillofacial Surgery Clinics An oral melanotic macule is a harmless dark spot found on the lip, most often the lower lip, or inside the mouth, either on the gums, inside the cheek, or on the roof of the mouth. An oral melanotic