Dark Patches Inside Mouth: 7 Alarming Causes Liv Hospital Pigmented Lesions of the Oral Mucosa Pocket Dentistry Pigmented Lesions of the Oral Mucosa Pocket Dentistry How Many Laser Sessions Are For Lip Pigmentation Treatment? Oral Melanotic Macule: Symptoms and Treatment Skinsight 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.