Malignant melanotic nerve sheath tumors in the spinal canal of psammomatous and non psammomatous type: Two case reports Metastatic Multifocal Malignant Peripheral Nerve Sheath Tumour in the Cervicothoracic Spinal Cord of a Dog Initially Mimicking Meningomyelitis Pathology Outlines Malignant melanotic nerve sheath tumor Peripheral nerve tumors Symptoms and causes Mayo Clinic Microsurgical management of giant malignant peripheral nerve sheath tumor of the scalp: two case reports and a literature review World Journal of Surgical Oncology Springer Nature Link