Conquer Colon Polyp Dx Coding for Clean Claims : ICD 10 ICD 10 Code C18.7: Malignant Neoplasm of Sigmoid Colon Pabau 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 Melanosis coli is dark brown black pigmentation of colorectal mucosa associated with chronic use of laxatives containing anthraquinone. Examples of such laxatives include senna and rhubarb derivatives. Clinical Importance: There is no association M79.1 ICD 10 Code: Myalgia Benign Discoloration Poses Questions