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

Topic Completed: 1 January 2006

Revised: 3 January 2019, last major update January 2006

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

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

See also: Epithelioid MPNST

Nat Pernick, M.D.
Page views in 2018: 565
Page views in 2019 to date: 534
Cite this page: Pernick N. Malignant peripheral nerve sheath tumor (MPNST). website. Accessed December 12th, 2019.
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
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