CNS tumor
Meningeal tumors
Anaplastic meningioma
Author: Jesse L. Kresak, M.D.
Editorial Board Member: Maria Martinez-Lage Alvarez, M.D.
Topic Completed: 1 September 2016
Minor changes: 27 August 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Anaplastic meningioma [title]
Table of Contents
Definition / general | Radiology description | Radiology images | Treatment | Gross description | Microscopic (histologic) description | Cytology images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Kresak J. Anaplastic meningioma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumoranaplasticmeningioma.html. Accessed January 25th, 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
Images hosted on other servers:
Very large bifrontal extra-axial mass
Treatment
- Gross total resection (major clinical factor in risk of recurrence)
- Postsurgical radiotherapy (Front Oncol 2013;3:227)
- Radiosurgery (Radiat Oncol 2014;9:38)
- Results with new "targeted" drugs include sunitinib (Neuro Oncol 2015;17:116) and bevazucimab (Ann Oncol 2010;21:2445)
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
Images hosted on other servers:
Squash prep
Positive stains
- Vimentin (100%), Ki67 / MIB1 (usually > 20%), strong EMA (89% although often decreases in recurrences)
- Somatostatin receptor 2A (Acta Neuropathol 2015;130:441)
- Cytokeratin 75% (Mod Pathol 2004;17:1129)
- Weak / focal CD99 (15%), weak / focal bcl2 67% (Am J Clin Pathol 2000;114:84)
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
- Atypical meningioma
- Glioma
- Hemangiopericytoma / solitary fibrous tumor: STAT6+, EMA-, CD99+, bcl2+, usually none of above deletions (Hum Pathol 2004;35:1413)
- Metastasis
Additional references
