Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review A Case Report of Oral Malignant Melanoma: A Silent Killer Cureus 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. Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer COM March 2009 Diagnosis UW School of Dentistry