Brain metastases as primary manifestation of a melanocytic malignant peripheral nerve sheath tumor in a 60 year old man BMC Neurology Springer Nature Link Fungating malignant peripheral nerve sheath tumor arising from a slow growing mass in the forearm: a case report and review of the literature Journal of Medical Case Reports Springer Nature Link Peripheral nerve sheath tumor Radiology Reference Article Radiopaedia.org Malignant peripheral nerve sheath tumor Wikipedia