CNS tumor
Mesenchymal and other tumors
Malignant peripheral nerve sheath tumor (MPNST)

Author: Nat Pernick, M.D. (see Authors page)

Revised: 11 September 2017, last major update January 2006

Copyright: (c) 2002-2017,, Inc.

PubMed Search: "Malignant peripheral nerve sheath tumor" central nervous system

See also: Epithelioid MPNST
Cite this page: Pernick, N. Malignant peripheral nerve sheath tumor (MPNST). website. Accessed June 20th, 2018.
Definition / general
  • Grade III or IV
  • Locally aggressive, metastasizes late
  • Usually arises in peripheral nerves, usually is a transformed plexiform neurofibroma (associated with neurofibromatosis 1) but may also be associated with radiation therapy or arise denovo; only rarely arises from malignant degeneration of schwannomas
  • Very rare in cranial cavity; rarely involves cranial nerves V and VIII
Case reports
Gross description
  • Fusiform or plexiform enlargement of nerve with thin capsule; homogeneous gray cut surface
Microscopic (histologic) description
  • Infiltrates nerve (important criteria since histologic features vary) and soft tissue with necrosis
  • Also marked hypercellularity (varies within tumor) with cells having spindle shaped nuclei with tapered ends, nuclear pleomorphism and brisk mitotic activity with abnormal forms
  • Patterns: fibrosarcoma, MFH, Schwann cells, triton tumor (rhabdomyosarcoma regions) and chondrosarcoma
Microscopic (histologic) images

Images hosted on other servers:

Not necessarily brain:

Malignant schwannoma

Extracranial trigeminal
nerve tumor with
hyperchromatic nuclei
and mitotic figures

Positive stains