CORRELATION OF VASCULAR ENDOTHELIAL GROWTH-FACTOR MESSENGER-RNA EXPRESSION WITH PERITUMORAL VASOGENIC CEREBRAL EDEMA IN MENINGIOMAS

Intracranial meningiomas are often complicated by peritumoral vasogeni c cerebral edema, which appears to result from increased microvascular permeability and extravasation of proteinaceous and plasma fluid into the adjacent peritumoral space. The source of such edema has long bee n mysterious. The contents of this paper support the concept that vasc ular endothelial growth factor (VEGF) production plays a significant r ole in edema formation. Vascular endothelial growth factor messenger R NA expression has been found in a wide range of intracranial neoplasms , including malignant gliomas, metastatic melanomas, meningiomas, and other benign tumors. Several studies have confirmed the importance of VEGF in tumorigenesis, neovascularization, and edema production. This study tests the hypothesis that the presence of peritumoral edema in m eningiomas is positively correlated with increased expression of VEGF mRNA. To investigate this hypothesis, 31 meningioma specimens were sub jected to Northern blot analysis, hybridization with a complementary D NA VEGF probe, and laser densitometry to determine the relative levels of VEGF mRNA expression. Magnetic resonance imaging was then used in a double-blind fashion to correlate the neuropathological tissue sampl es with the presence of preoperative peritumoral edema. Of 31 patients studied, 14 exhibited no edema and 17 exhibited some level of peritum oral fluid accumulation. There was a marked increase in VEGF expressio n in patients with edema (p = 0.0004, Wilcoxon-Mann-Whitney rank-sum t est). Meningiomas with peritumoral edema exhibited 3.4 times the level of VEGF mRNA as those without edema. These data demonstrate a strong link between VEGF mRNA expression and peritumoral edema and indicate t hat VEGF expression is an important factor in the etiology of edema ar ound meningiomas.