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. Pigmented Oral Lesions: Clues to Identifying the Potentially Malignant Consultant360 Melanocytic Lesions A Guide to Clinical Differential Diagnosis of Oral Mucosal Lesions Continuing Education Course dentalcare.com Citalopram Induced Oral Melanotic Macules in a Female Patient and a Review of the Literature Cureus Melanotic macule. Benign. Dark spot on labia (or lip). Analogous to lentigo simplex. Hyperpigmented basal keratinocytes & dermal melanophages. Slight in single basal melanocytes; NO nests. More info like this in Differentiating between early melanomas and melanocytic nevi: A state of the art review ScienceDirect