Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review Melanotic macules of the tongue in a newborn Journal of the American Academy of Dermatology Solitary pigmentation of the tongue: lentigo simplex or pigmented fungiform papilla? 05 May 03 Eng 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.