Differential Diagnosis of Pigmented Lesions in the Oral Mucosa: A Clinical Based Overview and Narrative Review 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 Pathology Outlines Oral mucosal melanoma Frontiers Mucosal Melanoma: Pathological Evolution, Pathway Dependency and Targeted Therapy Pathology Outlines Melanotic macule