Colonic melanosis due to excessive consumption of laxatives containing anthraquinone and senna : r MedicalGore 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 Melanosis coli Pathology Outlines Melanosis coli Frontiers Case report: Melanosis coli combined with colon cancer, causality or coincidence? Melanosis Coli