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. What to do with pigmented oral lesions? Pigmented Lesions Springer Nature Link Oral Melanotic Macule: Symptoms and Treatment Skinsight Labial melanotic macule