Edema and malignancy in meningiomas

Review of meningioma diagnosis and management

Meningiomas are the most common intracranial tumors in adult patients. Although the majority of meningiomas are diagnosed as benign, approximately 20% of cases are high-grade tumors that require significant clinical treatment. The gold standard for grading central nervous system tumors comes from the World Health Organization Classification of Tumors of the central nervous system. Treatment options also depend on the location, imaging, and histopathological features of the tumor. This review will cover diagnostic strategies for meningiomas, including 2021 updates to the World Health Organization's grading of meningiomas. Meningioma treatment plans are variable and highly dependent on tumor grading. This review will also update the reader on developments in the treatment of meningiomas, including surgery, radiation therapy and monoclonal antibody treatment.

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.

Natural history and volumetric analysis of meningiomas in neurofibromatosis type 2

OBJECTIVE

The objective of this paper was to describe the volumetric natural history of meningiomas in patients with neurofibromatosis type 2 (NF2).

METHODS

The authors performed a retrospective descriptive study by reviewing NF2 patients with meningiomas at their institution between 2000 and 2019. Demographic data were collected from the electronic medical records. Tumor volume was collected using volumetric segmentation software. Imaging characteristics including peritumoral brain edema (PTBE) and tumor calcification were collected for each patient from their first to most recent MRI at the authors’ institution. An increase of 15% or more per year from original tumor size was used as the cutoff to define growth.

RESULTS

A total of 137 meningiomas from 48 patients were included in the analysis. The average number of tumors per person was 2.9. Ninety-nine (72.3%) tumors were in female patients. The median length of follow-up from first imaging to last imaging was 32 months (IQR 10.9, 68.3 months). Most tumors were located in the cerebral convexity (24.8%), followed by the falcine region (18.2%) and spine (10.2%). The median tumor growth was 0.12 cm3/yr (IQR 0.03, 0.52 cm3/yr). At the time of first imaging, 21.9% of tumors had calcifications, while 13.9% of meningiomas had PTBE. Of 137 tumors, 52 showed growth. Characteristics associated with tumor growth included PTBE (OR 9.12, 95% CI 1.48–56.4), tumor volume (per cm3) at first imaging (OR 0.91, 95% CI 0.83–0.99), and 10-year increased age at first imaging (OR 0.57, 95% CI 0.43–0.74). PTBE had the shortest median time to growth at 9.2 months.

CONCLUSIONS

Although the majority of NF2-associated meningiomas do not grow in the short term, a wide range of growth patterns can be seen. Younger age at first imaging and presence of PTBE are associated with growth. Patients with these characteristics likely benefit from closer follow-up.

Atypical and Fibrous Meningioma with Differential Cerebral Blood Volume on Magnetic Resonance Imaging: A Case Report

Magnetic resonance imaging (MRI) features of meningiomas typically reveal a well-circumscribed and contrast-enhancing dural mass. Here we discuss the differences in MRI findings between typically benign and atypical meningioma, and their clinical implications. An MRI of a 67-year-old man revealed a substantial homogeneous enhancing tumor nodule. The MRI also showed two components in the tumor, and the regional cerebral blood volume (rCBV) was higher in the lateral than in the medial mass. A pathological examination also revealed features of both benign and atypical meningiomas. The Ki-67 labeling index was 1% on the medial side and 5% on the lateral side. There were clearly two components within the tumor mass, and the MRI revealed differential rCBV in the tumor. The results indicated a nontypical MRI of meningiomas, allowing for predictability of atypical meningiomas using MRI before surgical resection.

Association between tumor size and peritumoral brain edema in patients with convexity and parasagittal meningiomas

Background and purpose

Peritumoral brain edema (PTBE) is a common complication in meningioma and disruption of the tumor-brain barrier in meningioma is crucial for PTBE formation. To evaluate the association between meningioma size and PTBE, we measured meningioma volumes using the 3D slicer in patients with convexity and parasagittal meningiomas.

Methods

Receiver operating characteristic curve analysis was used to determine the optimal cut-off meningioma volume values for predicting PTBE occurrence. Logistic regressions were used to estimate the odds ratios for PTBE occurrence in patients with convexity and parasagittal meningiomas according to several predictive factors.

Results

A total of 205 convexity or parasagittal meningioma patients with no other brain disease who underwent one or more contrast-enhanced brain MRIs were enrolled in this 10-year analysis in two hospitals. The optimal cut-off meningioma volume value for prediction of PTBE in all study patients was 13.953 cc (sensitivity = 76.1%; specificity = 92.5%). If a meningioma is assumed to be a complete sphere, 13.953 cc is about 2.987 cm in diameter.

Conclusions

Our study suggests a cut-off value of 3 cm meningioma diameter for prediction of PTBE in patients with convexity and parasagittal meningiomas. We believe that we have revealed why the meningioma diameter of 3 cm is clinically meaningful.

Neuropsychological Outcomes after Surgery for Olfactory Groove Meningiomas

BACKGROUND

In recent years, several studies have reported abnormal pre- and postoperative neuropsychological functioning in patients with meningiomas located in the prefrontal cortex (notably the ventromedial region). In the case of olfactory groove meningiomas, the tumor is in direct contact with the inferior aspect of the prefrontal cortex, a cortical region with crucial roles in decision-making, cognition and memory functions, potentially negatively impacting neuropsychological functions.

MATERIALS AND METHODS

We retrospectively compared pre- and post-operative neuropsychological testing of 17 patients undergoing surgical removal of olfactory groove meningiomas in our institution between January 2013 and December 2018. Neuropsychological results were obtained from the patients' medical history and normalized as z-scores of their respective cognitive functions.

RESULTS

Assessment of cognitive follow-up showed an important heterogeneity among patients. Pre-operative cognitive impairment was observed in most patients, particularly in cognitive flexibility (mean z-score: -1.35). Immediate post-operative cognitive status showed an overall impairment in all domains of cognition, significant for the domains of attention (p = 0.0273) and flexibility (p = 0.0234) and almost significant for the domain of language (p = 0.0547). The late follow-up at one year showed a trend towards general improvement, although attention and flexibility remained impaired.

DISCUSSION

Olfactory groove meningiomas impact pre-frontal cortex cognitive functions, particularly in the domain of cognitive flexibility. After an initial postoperative worsening, patients tended to improve in most aspects after one year, aside from cognitive flexibility and attention.

Two-Staged Approach for Giant Hypervascular Meningioma Resection

Introduction:

Giant meningiomas represent very uncommon and challenging tumors. Surgical morbidity is high due to the difficult and complex approaches to devascularize these hypervascular lesions. In the present series, we demonstrate a two-staged approach for surgical resection of giant hypervascular meningiomas.

Patients and Methods:

Four such patients having giant hypervascular meningiomas between July 2017 and June 2019 were taken in the present study. There were two falco-tentorial, one anterior and middle parasagittal and falcine meningioma, and one sphenoid wing with convexity meningioma.

Results:

In the first stage, only the hypervascular bone was removed, and the dura was coagulated and excised. In the definitive stage, usually undertaken 5–8 days following the first surgery, the meningioma was excised, leading to Simpson's Grade 2 excision in two and Grade 3 excision in the remaining two patients. There was one mortality of a previously operated malignant meningioma (histopathologically proven), owing to a cardiac event in the patient, while the other three were discharged without any new neurologic deficit.

Conclusion:

Two-staged approach for giant meningiomas represents a safe and effective surgical management, tolerable for the patient and more comfortable for the neurosurgeon.

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.

Preoperative Evaluation of Tumor Adhesion to Adjacent Brain Tissue in Patients with Meningioma with BSMI Method and Its Comparison with the Width of Edema Around Tumor

Background

This study aims to investigate the ability of BSMI, to preoperative evaluation of tumor adhesion to adjacent brain tissue in patients with meningioma and comparing this method to the width of edema around tumor, using surgery findings as the reference standard.

Methods

Thirty patients with meningioma brain tumor who underwent surgery at Loghman hospital were selected for the study between November 2016 and January 2018. The level of edema according to the classification of Ide et al., (u1995) was compared with the surgical findings with blinded results, and neurosurgeons made a qualitative assessment of tumor adhesion at the time of resection. The ability of BSMI and level of edema to predict the surgical assessment of adhesion was tested using the Fisher Exact Test.

Results

BSMI method was conducted on patients with meningioma brain tumor, which judged 22 (73.3%) patients as adhesion (+) and 8 (26.66%) patients as adhesion (-). In this case, there was a significant relationship between BSMI judgment and surgical findings (p-value<0.0001). The sensitivity, specificity, precision and accuracy was high, at 91.30%, 85.71%, 95.45% and 90%, respectively. Using T2-Weighted SPACE sequence, of the 30 patients, 13 (43.3%) were judged as adhesion (+) and 17 (56.7%) as adhesion (-) from edema, whereas surgical findings evaluated 23 (76.7%) as adhesion (+) and 7 (23.3%) as adhesion (-).The sensitivity was moderate but the specificity was high, at 52.17% and 85.71%, respectively. Other criteria such as precision and accuracy were 62.31% and 60%, respectively.

Conclusions

BSMI evaluated adhesion of the tumor to the adjacent brain tissue with high-accuracy prior to surgery. This method was more effective than Edema method in evaluating adhesion between meningioma and the brain.

Magnetic resonance image manifestations of the atypical meningioma

Through retrospective analysis of 13 cases of magnetic resonance image (MRI) manifestations of atypical meningiomas confirmed by operation and pathology in the First Affiliated Hospital of Xinxiang Medical University, the objective of this study was to evaluate the diagnostic value of MRI in order to improve the accuracy rate of preoperative diagnosis. In this retrospective analysis of MRI findings for atypical meningiomas in First Affiliated Hospital of Xinxiang Medical University from January to July in 2012, the location, morphology and tumor signals and other tumor imaging characteristics were covered. In 13 cases of atypical meningioma patients of this group, most tumors were located at typical sites (10/13), mainly the falx cerebri, parasagittal, convexity, saddle area. Only two cases were at atypical locations, 1 in the cerebellar hemisphere and 1 in a lateral ventricle. Most of the tumors showed T1 and T2 isointensity signals, and necrosis, calcification, and peritumoral edema were always featured. DWI showed isointensity in 11 cases (11/13), and hyperintensity in 2. Some 9 cases had dural tail signs, 12 had accurate positioning (12/13), and 2 were postoperative recurrences. MRI has high value in the diagnosis of atypical meningiomas, with important roles in early clinical diagnosis, treatment and prognosis evaluation.

Correlation between magnetic resonance imaging grading and pathological grading in meningioma

OBJECT

This study investigated the specific preoperative MRI features of patients with intracranial meningiomas that correlate with pathological grade and provide appropriate preoperative planning.

METHODS

From 2006 to 2012, 120 patients (36 men and 84 women, age range 20-89 years) with newly diagnosed symptomatic intracranial meningiomas undergoing resection were retrospectively analyzed in terms of radiological features of preoperative MRI. There were 90 WHO Grade I and 30 WHO Grade II or III meningiomas. The relationships between MRI features and WHO histopathological grade were analyzed and scored quantitatively.

RESULTS

According to the results of multivariate logistic regression analysis, age ≥ 75 years, indistinct tumorbrain interface, positive capsular enhancement, and heterogeneous tumor enhancement were identified factors in the prediction of advanced histopathological grade. The prediction model was quantified as a scoring scale: 2 × (age) + 5 × (tumor-brain interface) + 3 × (capsular enhancement) + 2 × (tumor enhancement). The calculated score correlated positively with the probability of high-grade meningioma.

CONCLUSIONS

This scoring approach may be useful for clinicians in determining therapeutic strategy and in surgical planning for patients with intracranial meningiomas.

Evaluation of mast cells and hypoxia inducible factor-1 expression in meningiomas of various grades in correlation with peritumoral brain edema

Meningiomas are common primary brain tumors. However, they are often complicated by significant peritumoral brain edema, which leads to surgery difficulties and prolonged hospitalization. The aim of this study was to evaluate the presence of mast cells and expression of hypoxia inducible factor-1 (HIF-1) in correlation with the grade of meningioma and presence of peritumoral brain edema. Immunohistochemistry was performed with specific antibodies against tryptase (mast cells) and HIF-1 in low grade meningiomas (estimated as G1) and high grade meningiomas (estimated as G2 or G3). Peritumoral brain edema observed in MRI was graded using Steinhoff classification. Tryptase expression was observed in 40.4 % low grade meningiomas and in 90 % high grade cases; HIF-1 in 55.7 % low grade and in 84 % high grade meningiomas. There was a statistically significant correlation between HIF-1 and tryptase expression in both groups (p = 0.003). Presence of peritumoral brain edema statistically correlated with tryptase (p = 0.001) and HIF-1 expression (p = 0.004). Mast cells as well as hypoxia are involved in meningioma progression, and may be associated with the formation of peritumoral brain edema leading to surgery complication and recovery. Therefore, they may be useful markers in predicting the clinical course of meningioma cases.

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.

Surgical Outcome of Treating Grades II and III Meningiomas: A Report of 32 Cases

Aim. To evaluate the frequency of atypical and malignant meningiomas and analyze recurrence rate; to study the morbidity and mortality of these tumors compared to benign meningiomas. Methods. During 1992–2007, 16 patients with malignant and 16 patients with atypical meningioma were operated in Neurosurgery Department of Thessaloniki's Papanikolaou Hospital. We analyzed tumor histology, location, and extent of surgical resection with respect to tumor reappearance and patients' outcome and compared the behavior of benign versus nonbenign meningiomas. Results. Malignant meningiomas accounted for 4.4% (16 patients) and atypical meningiomas for another 4.4% of the series of patients (353) who were operated for intracranial meningioma at our department that period. Malignant meningiomas recurred at a rate of 75% and atypical meningiomas recurred at a rate of 41.6%. There was a significant association of the histological classification (benign, atypical, and malignant) with recurrence (P < 0.01). The recurrence rate after complete resection was 13.8%. The recurrence rate for incomplete resection was 46.7%. Extent of tumor removal was significant to recurrence (P < 0.001) for benign as well for atypical and malignant meningiomas. Tumor location (P > 0.05) was not significant to recurrence. Conclusions. Atypical and malignant meningiomas appeared at a rate of 8.8% of our series of intracranial meningiomas. They showed a significant predisposition to recur. These rare subtypes have higher morbidity and mortality rates than benign meningiomas. Recurrence depends primarily on the extent of surgical removal and on the histological characterization of the tumor as atypical or malignant.

Acute cerebral infarction masked by a brain tumor

We report on an 81-year-old man who presented with left limbs weakness and was brought to the emergency room where a brain computed tomography revealed a tumor at the right parasellar region. The patient was admitted to the neurosurgery department, and the symptoms were thought to be due to the tumor mass effect. The final diagnosis turned out to be acute ischemic infarction with an incidentally found brain tumor following angiography and magnetic resonance imaging.

Do aggressive imaging features correlate with advanced histopathological grade in meningiomas?

Atypical and malignant meningiomas are more likely to recur than benign meningiomas. We aimed to distinguish atypical and malignant meningiomas from benign meningiomas based on imaging findings. Between 2004 and 2007, a total of 75 patients with resected intracranial meningiomas were retrospectively reviewed. Histopathological grades were assigned as benign and atypical/malignant meningiomas according to the World Health Organization (WHO) classification. All patients received preoperative CT scans and MRI studies. Six aggressive imaging features were evaluated and compared between the two groups: (i) intratumoral cystic change; (ii) hyperostosis of the adjacent skull; (iii) bony destruction; (iv) extracranial tumor extension through the skull base foramina; (v) arterial encasement; and (vi) peritumoral brain edema. There were 59 benign and 16 atypical/malignant meningiomas. Only intratumoral cystic change and extracranial tumor extension through the skull base foramina were more prevalent in atypical/malignant meningiomas (p=0.001). Hence, these two imaging features might be potential markers of atypical/malignant meningiomas.

Utilization of dynamic CT perfusion in the study of intracranial meningiomas and their surrounding tissue

OBJECTIVE

To use CT perfusion (CTP) to assess levels of ischemia in brain areas around intracranial meningiomas.

MATERIALS AND METHODS

Fifteen patients with intracranial meningiomas were analysed preoperatively with CTP study. The cerebral blood flow (CBF), cerebral blood volume (CBV) and time to peak (TTP) were measured in the edema, peritumoral edema and in the normal areas of brain.

RESULTS

The peritumoral edema measured a mean CBF of 17.36 ml/min/100 ml (median=15.8) and the mean CBF value in the whole edema was 93.86 ml/min/100 ml (median=79.9). The mean CBV measured in the peritumoral edema was 2.7 (median=2.3) and the measured mean CBV of edema was 15 (median=13.2). In the region of the peritumoral edema, the mean CBF and CBV were lower than in the edema bed. Normal brain remote from the edema measured less CBF (mean=28.36 ml/min/100 ml, median=29.7) and CBV (mean=4.1, median=3.8) than the edema. Six patients were noted to have CBF of less than 15 ml/min/100 ml in the perilesional edema. The measured mean CBF and CBV in the normal area of brain were higher than in the peritumoral edema, while the TTP was greater in the perilesional edema (mean=11, median=10.4) when compared with areas of normal brain (mean=9.9, median=9.5) with statistically significant p values.

CONCLUSION

The values obtained elucidate the fact that perilesional edematous areas are ischemic. By subset analysis, it may be possible to identify those areas with recoverable tissue from non-recoverable tissue.

Expression of vascular endothelial growth factor-A and mRNA stability factor HuR in human meningiomas

We studied the expression of vascular endothelial growth factor-A (VEGF-A) and mRNA stability factor HuR in 40 supratentorial meningiomas using RT-PCR, ELISA and immunohistochemistry, and analyzed their associations with the clinicopathological characteristics, including microvascular density (MVD), peritumoral brain edema (PTBE), histological subtypes and grades, and the performance of preoperative arterial embolization. Furthermore, we investigated the involvement of HuR in the upregulation of VEGF-A expression using primary meningioma cell cultures. The level of VEGF-A is elevated in meningiomas with PTBE and in higher grade meningiomas. Preoperative arterial embolization did not significantly increase the level of VEGF-A, but it did increase the expression of HuR in tumor tissues. HuR expression was correlated positively with VEGF-A expression in meningioma tissues. In in vitro experiments, hypoxia induced the upregulation of VEGF-A expression and the cytoplasmic translocation of HuR protein in meningioma cells, and inhibition of the cytoplasmic translocation of HuR reduced the upregulation of VEGF-A expression in meningioma cells. These findings suggest that the expression of VEGF-A relates to the development of PTBE with meningiomas and the histological grade, and that HuR is involved in the upregulation of VEGF-A expression in human meningiomas.

Expression of cell adhesion proteins and proteins related to angiogenesis and fatty acid metabolism in benign, atypical, and anaplastic meningiomas

Most meningiomas are benign tumours of arachnoidal origin, although a small number have high proliferative rates and invasive properties which complicate complete surgical resection and are associated with increased recurrence rates. Few prognostic indicators exist for meningiomas and further research is necessary to identify factors that influence tumour invasion, oedema and recurrence. Paraffin sections from 25 intracranial meningiomas were analysed for expression of the proteins vascular endothelial growth factor (VEGF), VEGF receptors Flt1 and Flk1, E-cadherin, metalloproteinases 2 and 9 (MMP2, MMP9), CD44, receptor for hyaluronic acid-mediated motility (RHAMM), hyaluronic acid (HA), CD45, cyclooxygenase 2 (COX2), brain fatty acid binding protein (BFABP), Ki67, and proliferating cell nuclear antigen (PCNA). Correlations among protein expression were found for several markers of proliferation (Ki67, PCNA, MI) and microvessel density (MVD). COX2 expression increased with increasing with tumour grade and correlated with Ki67, PCNA, MI, MVD, and BFABP. BFABP expression also correlated with Ki67 and PCNA expression. Relationships were also identified among angiogenic factors (VEGF, Flt1, Flk1) and proliferation markers. Oedema was found to correlate with MMP9 expression and MMP9 also correlated with proliferation markers. No correlations were found for MMP2, E-cadherin, or CD44 in meningiomas. In conclusion Ki67, PCNA, MI, MVD, BFABP, and COX2 were significantly correlated with meningioma tumour grade and with each other. These findings, by correlating both intracellular fatty acid transport and eicosanoid metabolism with tumour proliferation, as determined by Ki67 labelling and mitotic index, suggest fatty acids are involved in the progression of meningiomas.