Frontiers Case report: A rare case of massive peripheral nerve melanotic schwannoma and review of the literature Pathology Outlines Malignant melanotic nerve sheath tumor From melanocytes to melanomas Nature Reviews Cancer Since melanoma develops on the skin, it can often be seen without special tests. Regular skin self exams and professional skin checks by a dermatologist can help detect melanoma early, when Malignant melanotic nerve sheath tumors in the spinal canal of psammomatous and non psammomatous type: Two case reports