Peritumoral brain edema and cortical damage by meningioma

The role of aquaporin 4 in brain tumors: implications for pathophysiology, diagnosis and therapy

Primary brain tumors are a heterogeneous group of tumors that arise from cells intrinsic to the central nervous system (CNS). Aquaporin-4 (AQP4) has been implicated in the pathogenesis of brain tumors. Previous reports have documented a relationship between AQP4 and several molecular pathways associated with the etiology of brain tumors, such as apoptosis, invasion and cell migration. AQP4 affects apoptosis via cytochrome C, Bad and Bcl-2, as well as invasion and migration via IDO1/TDO-Kyn-AhR axis, lncRNA LINC00461, miR-216a, miRNA-320a and MMPs. In addition, inhibition of AQP4 mitigates the progression of brain tumors. This review summarizes current knowledge and evidence regarding the relationship between AQP4 and brain tumors, and the mechanisms involved.

Sphenoid wing meningiomas: peritumoral brain edema as a prognostic factor in surgical outcome

Sphenoidal meningiomas constitute 18% of intracranial masses, and still present a difficult surgical challenge. PTBE has been associated with several complications and future recurrence. This study aims to evaluate the outcome of the operatively treated sphenoid wing meningiomas in relation to PTBE as a prognostic factor in a series of 65 patients. The clinical materials of 65 patients with SWM treated microsurgically between 2007 and 2020 were analyzed retrospectively. Follow-up ranged from 6 to 156 months (median, 86). Clinical outcomes include postoperative major neurological deficit, quality of life using KPS, recurrence, and mortality rates. The mean age of patients was 53.9 years (range 20-74), males 24.6% and females75.4%. An edema index (EI) of 1 (40%) was considered as absent edema, and EI > 1 (60%) indicated present edema. Total resection (Simpson I-II) was achieved in 64.6% and subtotal (Simpson IV) in 13.8%. Postoperative complications included vision impairment in 3 patients, motor weakness 6, third nerve palsy 6, intraoperative bleeding and edema 5, and MCA infarct 2, recurrence in 17% and 7.7% died. In univariate analysis, we found that the PTBE is one of the serious risk factors in the immediate surgical outcomes and complication, though more data is needed to support this claim, while having a negative effect on postoperative KPS at short-term follow up (χ² = 6.44, p = 0.011). PTBE was associated with decline in KPS and quality of life in the early postoperative period (three months) while showing no significant effect at long-term outcomes.

CORRELATION OF PERITUMORAL BRAIN EDEMA WITH MORPHOLOGICAL CHARACTERISTICS AND KI67 PROLIFERATIVE INDEX IN RESECTED INTRACRANIAL MENINGIOMAS

The aim of the study was to analyze correlation between morphological characteristics of intracranial meningiomas and Ki67 labeling index (Ki67 LI), and their influence on peritumoral brain edema (PTBE). There were 41 consecutive patients with intracranial meningiomas surgically treated at the Department of Neurosurgery, Zenica Cantonal Hospital, Zenica, Bosnia and Herzegovina, during the period from January 2010 to December 2015. We reviewed clinical data including patient age, gender, magnetic resonance imaging (MRI) characteristics of the tumor and peritumoral edema, tumor margins, intraoperative characteristics, histopathologic grade and Ki67 LI. In all cases, follow up MRI was obtained at about three months after resection and PTBE was analyzed. Our research showed the tumor volume, tumor margins, and intraoperative signs of arachnoidal and pial invasion to be associated with PTBE in intracranial meningiomas. Ki67 LI expression correlated with PTBE. This study showed the resolution of PTBE to depend on invasive behavior of meningioma and KI67 LI. PTBE, pial/cortical and arachnoidal invasion significantly influence the extent of surgical resection.

Expression of aquaporin 5 and the AQP5 polymorphism A(-1364)C in association with peritumoral brain edema in meningioma patients

Aquaporins (AQP) are a growing family of water-channel proteins, numbering 13 to date. Recent studies have reported AQP1 and AQP4 to be involved in the development and resorption of brain edemas of different origin. Other AQPs have also been detected in brain tissue, but their impact on brain edema remains to be shown. To evaluate a possible role of AQP5 in brain edema, we investigated the association of AQP5 expression and the functional AQP5 promoter polymorphism A(-1364)C with occurrence and intensity of peritumoral edema in meningioma patients. Peritumoral edema was classified in three degrees based on preoperative imaging in 89 meningioma patients treated at the University Hospital Essen between 2003 and 2006. AQP5 expression was assessed immunohistochemically in tumor tissue obtained during neurosurgical tumor resection. Genotypes of the A(-1364)C polymorphism were determined using the "slowdown" polymerase chain reaction. Higher levels of AQP5 expression were significantly correlated with the AQP5-1364 AA genotype (P = 0.02). AQP5 expression was positively correlated with edema (P = 0.04). AQP5 genotypes were not significantly associated with the occurrence, but with the intensity of peritumoral brain edema (P = 0.04). In our cohort, 40 % of patients with grade I, 66.7 % with grade II, and 76.5 % with grade III edema possessed at least one A allele. Development and intensity of peritumoral edema in meningiomas are associated with AQP5 expression. The intensity of edema correlates with the AQP5 A(-1364)C genotype. This suggests AQP5 as an interesting new candidate involved in peritumoral brain edema in meningioma patients.

Increased co-expression of macrophage migration inhibitory factor and matrix metalloproteinase 9 is associated with tumor recurrence of meningioma

BACKGROUND AND OBJECTIVE

We detected the expression of MIF and matrix metalloproteinase 9 (MMP9) in meningiomas to determine whether they are valuable recurrence predictor for meningioma.

METHODS

67 cases of meningiomas, including 57 benign tumors (WHO grade I) and 10 non-benign tumors (WHO grade II and III), were collected, and expression of MIF and MMP9 in tissue microarray was evaluated immunohistochemically. The correlations between immunostainings and clinicopathological parameters, as well as the follow-up data of patients, were analyzed statistically.

RESULTS

Increased expressions of both MIF (58.2%, 39/67) and MMP9 (55.2%, 37/67) were significantly associated with microvessel density (MVD) of tumor, but only dual high-expression of MIF and MMP9 was in relation to tumor invasion (P=0.016) and tumor recurrence (P=0.001). Based on univariate analysis, histological grade, tumor invasion and co-expression of MIF and MMP9 were significant predictors for recurrence. However, only histological grade and co-expression of MIF and MMP9 in tumor were independent recurrence factors with a hazard ratio of 49.033 (P=0.002) and 37.766 (P=0.002) in multivariate analysis.

CONCLUSIONS

Together with histological grade, increased co-expression of MIF and MMP9 in tumor might be a valuable predictor for recurrence, especially for benign meningiomas.

Predicting the probability of meningioma recurrence in the preoperative and early postoperative period: a multivariate analysis in the midterm follow-up

We reviewed the clinical, radiological, surgical, and histopathological features of patients with meningiomas to identify factors that can predict tumor recurrence after "microscopic total removal," to improve preoperative surgical planning, and to help determine the need for close radiological observation at shorter intervals or the need for radiotherapy as an adjuvant treatment in the early postoperative period. Clinical data, magnetic resonance imaging studies, angiographic data, operative reports, and histopathological findings were examined retrospectively in 137 patients with a meningioma treated microsurgically and with no evidence of residual tumor on postoperative MR images. Based on univariate analysis, tumor size, a mushroom shape, proximity to major sinuses, edema, osteolysis, cortical penetration, signal intensity on T2-weighted MRIs, pial-cortical arterial supply, presence of a brain-tumor interface in surgery, Simpson's criteria, and histopathological classification were significant predictors for recurrence. However, age, gender, location of tumor, dural tail, calcification, signal intensity on T1-weighted images, and histopathologic subtypes in the benign group were not significant predictors. By Cox regression analysis the most important variables related to the time to recurrence were mushroom shape, osteolysis, dural tail, and proximity to major sinuses. Aggressive surgical therapy with wider dural removal should be considered in the presence of the preoperative predictors of a recurrence. Close radiological observation at shorter intervals or radiotherapy should be considered as adjuvant therapy in high-risk patients based on surgical findings predicting recurrence related to the brain-tumor interface, Simpson's criteria, and histopathological findings in the early postoperative period.

Progress in the diagnosis and treatment of patients with meningiomas. Part I: diagnostic imaging, preoperative embolization

BACKGROUND

The clinical management of patients with meningiomas has changed over the past decade. Change has occurred because of a variety of factors including improved diagnostic imaging, better results with surgery and interventional neuroradiology, and the advent of radiosurgery. Recent clinical studies from several disciplines have provided new information on topics germane to the management of patients with meningiomas. Collecting this information into a series of review articles would have significant value, primarily for neurosurgeons.

OBJECTIVE

The purpose of this first paper is to bring together and evaluate the available data on: 1) noninvasive diagnostic imaging of meningiomas, including magnetic resonance imaging (MRI), computed tomography (CT) scanning, and MR angiography, venography and spectroscopy; 2) the present role of cerebral angiography in patients with meningiomas; and 3) the current status of preoperative embolization for these tumors.

RESULTS

With the advent of MR technology, the quality of diagnostic imaging for meningiomas has improved dramatically, and this is reflected in more sophisticated preoperative planning. MR imaging provides improved delineation of dura and sinus involvement, and even information about a tumor's consistency. Meningiomas have characteristic neuroimaging features, yet other lesions can still mimic a meningioma. MR venography can be used to demonstrate sinus patency, but intra-arterial cerebral angiography gives the most precise information concerning the degree of tumor involvement of critical vascular structures, and the anatomy of arterial feeders. In trained hands, superselective catheterization for preoperative embolization of meningiomas is feasible, and seems to be reasonably safe.

CONCLUSIONS

MR imaging, CT scans, and cerebral angiography can currently be used in a complementary fashion to diagnose, evaluate, and treat patients with meningiomas, with a high degree of clinical certainty. Angiography is used to determine the sites of blood supply to the tumor, which can then be attacked first intraoperatively, making tumor removal easier. Preoperative embolization continues to have value in selected patients, including those in whom the blood supply to the tumor is difficult to access at the time of surgery.