This is a very rare case of metastatic oral mucosal melanoma to the colon with an unusual presentation mimicking melanosis coli. The colonoscopy findings show no mass effect but multiple hyperpigmented lesions Oral Melanoacanthoma: Case Series of 33 Cases and Review of the Literature Head and Neck Pathology Springer Nature Link Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review Pathology Outlines Melanotic macule Pathology Outlines Pigmented lesions vulva Melanotic macules of the tongue in a newborn Journal of the American Academy of Dermatology