Physiological oral melanin pigmentation in a South African sample: A clinical study Masilana 2017 Journal of Investigative and Clinical Dentistry Wiley Online Library What Caused These Multiple Hyperpigmented Macules of the Mouth? 05 May 03 Eng Primary malignant melanoma of the tongue CJS 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.