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 A rare case of melanosis ilei of unclear etiology ScienceDirect Frontiers Case report: Melanosis coli combined with colon cancer, causality or coincidence? Hepatitis C virus (HCV) genotype 1b displays higher genetic variability of hypervariable region 1 (HVR1) than genotype 3 Scientific Reports