Microscopic anatomy of the brain–meningioma interface

Abstract

We analyzed the relation between meningioma and the brain in 50 surgical cases. So-called capsule formation was seen in 20 meningiomas, of which 13 were categorized as thin and 7 as thick. In 21 meningiomas the arachnoid membrane was intact, and 10 meningiomas had no underlying arachnoid membrane. The other 19 tumors showed partial disruption of the arachnoid membrane. The degree of arachnoid disruption correlated with the tumor grade, perifocal edema, pial blood supply on angiography, and tumor size. The existence of brain invasion correlated with the tumor grade and partially with tumor size. In case of invasive tumor, GFAP-positive cells were found deep in the tumor, usually in contact with blood vessels. The axons in gliotic brain often showed degenerative changes such as ballooning or varicose swelling. Meningiomas were usually demarcated by a basement membrane that was collagen type 4 (Col4)-positive. However, atypical and anaplastic meningiomas usually lacked Col4 staining at the interface. In two benign meningiomas that looked like an invasive growth, Col4 staining was seen above the brain. A pia mater-like structure covered the tumor surface in both cases. We could not demonstrate a relation between the expression of matrix metalloproteinase (MMP)-2 or MMP-9 and arachnoid disruption or brain invasion.

Seizures in supratentorial meningioma: a systematic review and meta-analysis

“…27,34,45–47,50,65,67 Two studies found edema to be most common with convexity or parasagittal meningiomas, 11,38 but another did not observe a relationship to location, 29 and no consistent association between edema and tumor size or pathological subtype is present across studies. 11,29,38,49 Some groups have also suggested a relationship between brain invasion and edema, 39,44 although it is unclear if edema resulting from tumor infiltration differs from vasogenic edema in meningiomas without invasion. 31,39 Brain invasion was not investigated in our study, as these data were not reported in the source studies we examined.…”

Metabolic alterations in the peritumoral brain in cases of meningiomas: 1H-MRS study

“…Invasive meningiomas disrupt structural integrity of the arachnoid and pia mater, which is followed by disintegration of the cortical layer and glial matrix [12][13][14]. It facilitates excretory-secretory phenomena with direct influence of the tumor metabolites on the adjacent brain parenchyma, results in development of pial vascular supply to the neoplasm, and alters blood-brain barrier permeability with typical formation of the vasogenic brain edema [15][16][17][18][19][20].…”

Proteins involved in regulating bone invasion in skull base meningiomas

“…The biological role and functional contribution of MMPs is complex and their role in meningiomas is far from established. Previous studies have focused on establishing the role of MMP2 in meningiomas, in particular as it relates to tumor recurrence, brain invasion, and peritumoral edema, and the data is conflicting [10, 19, 21, 23, 24, 26, 28–31, 48]. Though some studies found higher MMP2 expression levels in recurrent meningiomas [28, 48], others have found no association between meningioma grade and MMP2 levels [29].…”

“…Though some studies found higher MMP2 expression levels in recurrent meningiomas [28, 48], others have found no association between meningioma grade and MMP2 levels [29]. No correlation between MMP2 expression level and brain-invasive potential of meningiomas has been found to date [23, 24, 26]. Studies focused on the predictive potential of MMP2 on meningioma peritumoral edema have been contradictory, with Paek et al [30] suggesting a positive association, whereas Panagopolous et al [31] noted no such association.…”