CNS tumor

Meningeal tumors

Anaplastic meningioma

Editorial Board Member: Maria Martinez-Lage, M.D.
Jesse L. Kresak, M.D.

Topic Completed: 1 September 2016

Minor changes: 27 August 2020

Copyright: 2002-2021,, Inc.

PubMed Search: Anaplastic meningioma [title]

Jesse L. Kresak, M.D.
Page views in 2020: 5,620
Page views in 2021 to date: 6,472
Cite this page: Kresak J. Anaplastic meningioma. website. Accessed December 3rd, 2021.
Definition / general
  • WHO 2016 definition: a meningioma that exhibits overtly malignant cytology (resembling that of carcinoma, melanoma or high grade sarcoma) or markedly elevated mitotic activity
  • Grade III
  • Also called malignant meningioma
  • 1 - 3% of meningiomas
  • Either denovo, associated with recurrent tumors or associated with prior radiation (J Neurooncol 2005;74:195, Med Pediatr Oncol 1995;24:265)
  • Associated with aberrant CpG island hypermethylation profile (Hum Pathol 2005;36:416)
  • Occasional metastases beyond the CNS (Clin Neurol Neurosurg 2011;113:592)
  • Recurrence rates are 50 - 94% and overall survival is estimated to be 2 - 5 years
Radiology description
  • MRI may show irregular tumor borders, heterogenous tumoral enhancement and peritumoral edema suggesting a high grade meningioma
Radiology images

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Very large bifrontal extra-axial mass

Gross description
  • Dural based
  • May be well circumscribed or readily adherent to brain parenchyma
  • Size can vary widely
  • Gross necrosis can be present
Microscopic (histologic) description
  • Criteria to be termed anaplastic are either 20+ mitotic figures/10 HPF or displaying frank malignant, sarcomatous or carcinomatous histology
  • Most also show extensive necrosis
  • Variable invasion of brain
  • Proving meningothelial origin can be challenging
Cytology images

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Squash prep

Positive stains
Negative stains
Molecular / cytogenetics description
  • Loss of 6q, 9p, 10 and 14q
  • Gains of 1q, 9q, 15q, 17q, 20q
  • Deletion of 1p21, which includes CDKN2A
  • NF2 mutation in 70% of cases
  • TERT promoter mutations in 20% of cases (J Natl Cancer Inst 2016;108:djv377)
Differential diagnosis
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