CNS tumor
Meningeal tumors
Invasive meningioma

Author: Jesse Kresak, M.D. (see Authors page)
Editor: Anthony T. Yachnis, M.D.

Revised: 6 September 2017, last major update February 2014

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

PubMed Search: "Invasive meningioma"

Cite this page: Kresak, J. Invasive meningioma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorinvasivemeningioma.html. Accessed December 12th, 2017.
Definition / general
  • Meningioma of any subtype invading into adjacent brain parenchyma
  • Invasion into brain parenchyma upgrades the meningioma to WHO grade II, even if other criteria are lacking
  • Associated with a high risk of recurrence (Neurosurgery 2010;67:1124)
  • Invasion into bone, dura or sinuses, which does NOT change grade, is insufficient for this diagnosis
  • Note: all invasive meningiomas are included within the category of atypical meningioma, which also includes noninvasive tumors with other features
  • SPARC may be associated with invasiveness (Clin Cancer Res 1999;5:237)
Pathophysiology
  • Pathogenesis leading some meningiomas to invade adjacent structures is not fully elucidated
  • However, some studies suggest an epithelial to mesenchymal transition with loss of adhesion molecules (Front Biosci (Elite Ed) 2012;4:889)
Radiology description
  • MRI of brain invasive meningioma may show increased peritumoral edema
Radiology images

Images hosted on other servers:

MRI of benign meningioma with bony invasion

Atypical meningioma with surrounding edema

Treatment
Gross description
  • Dural based
  • Readily adherent to adjacent CNS tissue
  • Consistency may vary from firm to soft
Microscopic (histologic) description
  • May have histology of any subtype of meningioma
  • Invades into brain parenchyma in nests or protruding tongues
  • Loss of clear arachnoid plane at the tumor to brain interface
Microscopic (histologic) images

Images hosted on other servers:

Tumor invading sinonasal mucosa

Nests and tongues of tumor invading brain

Brain invasion highlighted by GFAP


Clear arachnoid plane between brain and tumor - NOT invasion

SPARC

Diffuse infiltrative
invasion at the
tumor / brain
interface

Tumor invasion into the adjacent dura

Nodular invasion at the tumor / brain interface

Positive stains
Negative stains
  • GFAP is negative in the tumor but is useful to highlight brain invasion
Differential diagnosis