Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review Pigmented Lesions Springer Nature Link Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review An oral melanotic macule is a harmless dark spot found on the lip, most often the lower lip, or inside the mouth, either on the gums, inside the cheek, or on the roof of the mouth. An oral melanotic Pigmentation on the oral mucosa, hands, and feet European Journal of Internal Medicine Smoker's melanosis Wikipedia