Pigmented Lesions of the Oral Mucosa Springer Nature Link Labial melanotic macule (brown spot on lip) (Stony Brook Case 1) dermatology dermatopathology Labial Lentigo (labial melanotic macule) Cancer Therapy Advisor 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. Does anyone know what this black mark on my lip is? Started last August so it's I've had it nearly a year, was living in Spain at the time for 6 months