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 Melanoma Wikipedia Rare malignant melanotic nerve sheath tumors of the upper limb nerves: utility of high frequency ultrasonography in preoperative imaging Skeletal Radiology Springer Nature Link Inflammation lights the way to metastasis Nature Anterior Uveal Melanocytic Neoplasia in Dogs & Cats Tumoral Melanosis New England Journal of Medicine