label: Malignant Peripheral Nerve Sheath Tumor
label_lc: malignant peripheral nerve sheath tumor
description: "An uncommon, highly aggressive malignant tumor, arising from the peripheral nerves and affecting mostly adults in their third to sixth decades of life.  It usually occurs in medium-sized and large nerves of the buttock, thigh, upper arm, or the paraspinal region.  It may be associated with neurofibromatosis 1 (NF1)."