Malignant peripheral nerve sheath tumor (MPNST) is a rare and often aggressive soft tissue sarcoma occurring in a wide range of anatomical sites. The disease is MONDO_0017827 (malignant peripheral nerve sheath tumor). Also known as: MPNST, Malig. periph. nerve sheath tum., malignant neoplasm of peripheral nerve sheath, malignant neoplasm of the peripheral nerve sheath, malignant neurilemmoma, malignant neurilemoma, malignant neurofibroma, malignant peripheral nerve sheath neoplasm.