Metastatic Melanoma: Symptoms, Stages, Treatment Metastatic Melanoma Inflammation lights the way to metastasis Nature Pathology Outlines Malignant melanotic nerve sheath tumor 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 Malignant melanotic nerve sheath tumor Radiology Reference Article Radiopaedia.org