Invasive Meningiomas Research Articles

Differential Expression of Proteins and Genes at the Tumor-Brain Interface in Invasive Meningioma.

Most meningiomas are dural-based extra-axial tumors in close contact with the brain. Expression of genes and proteins at the tumor-brain interface in brain-invasive meningioma is basically unknown. Using the NanoString pan-cancer panel, differential expression of genes in the invasive edge versus main tumor body was determined in 12 invasive meningiomas (comprising the discovery cohort), and 6 candidate genes: DTX1, RASGRF1, GRIN1, TNR, IL6, and NR4A1, were identified. By immunohistochemistry, DTX1 and RASGRF1 expression correlated with gene expression, and were studied in an expanded cohort of 21 invasive and 15 noninvasive meningiomas, together with Ki-67. Significantly higher expression of DTX1, RASGFR1, and Ki-67 was found in the invasive edge compared with the main tumor body. Increased expression of RASGRF1 and Ki-67 was more clearly associated with brain invasion. The situation with DTX1 was less definitive since increased expression was observed in meningiomas both at the invasive edge and when in close contact with brain but without invasion. Pathway analyses identified significant links between DTX1 and RASGRF1 and key biological processes, including cell-cell adhesion, and signaling pathways including Notch, RAS, MAPK, and Rho. Higher expression of DTX1, RASGRF1, and Ki-67 in the brain-invasive area of meningiomas suggests that these proteins play a role in the process of brain invasion.

Nursing care for patients with recurrent invasive meningioma undergoing salvage boron neutron capture therapy: a case report

Nursing care for patients with recurrent invasive meningioma undergoing salvage boron neutron capture therapy: a case report

MNGA-02 MENINGIOMA WITH CONTROLATERAL SUB-DURAL HEMATOMA: CASE REPORT AND LITERATURE REVIEW

Abstract BACKGROUND Meningiomas account for around 20% of primary intracranial tumors. It is the most common benign brain tumor. The association of meningiomas with subdural hematoma is rare, and very few cases have been reported in the literature. The pathophysiological mechanisms are not yet fully understood. We therefore report a case of chronic subdural haematoma associated with a meningioma and review the relevant literature. CASE PRESENTATION A 72-year-old patient with known hypertension and a right basifrontal lesion discovered a few months previously. He was brought to emergency by his daughter for multiple comitial seizures and confusion. On clinical examination, the patient was conscious but confused, with anosmia and no sensory or motor deficits. A brain scan and MRI revealed a right parasagittal basifrontal meningioma associated with a chronic left subdural hematoma. The patient had no coagulation disorders. He underwent removal of the meningioma using a bifrontal approach, cranialisation of the sinuses, and drainage of the hematoma using an external subdural shunt. The postoperative course was favorable. Post-operative imaging showed satisfactory Simpson 1 resection and good drainage. The anatomopathological examination concluded that the meningioma had a meningothelial morphological subtype of doubtful invasiveness, suggesting a grade 2 invasive meningioma or a grade 1 meningothelial meningioma. No additional treatment was required. CONCLUSION The presence of a meningioma should always be suspected in the presence of an acute non-traumatic subdural hematoma. To obtain a more comprehensive pathophysiological explanation of the association, a meta-analysis involving a larger number of cases and a larger series would be necessary.

MRI- and DWI-Based Radiomics Features for Preoperatively Predicting Meningioma Sinus Invasion.

The aim of this study was to use multimodal imaging (contrast-enhanced T1-weighted (T1C), T2-weighted (T2), and diffusion-weighted imaging (DWI)) to develop a radiomics model for preoperatively predicting venous sinus invasion in meningiomas. This prediction would assist in selecting the appropriate surgical approach and forecasting the prognosis of meningiomas. A retrospective analysis was conducted on 331 participants who had been pathologically diagnosed with meningiomas. For each participant, 3948 radiomics features were acquired from the T1C, T2, and DWI images. Minimum redundancy maximum correlation, rank sum test, and multi-factor recursive elimination were used to extract the most significant features of different models. Then, multivariate logistic regression was used to build classification models to predict meningioma venous sinus invasion. The diagnostic capabilities were assessed using receiver operating characteristic (ROC) analysis. In addition, a nomogram was constructed by incorporating clinical and radiological characteristics and a radiomics signature. To assess the clinical usefulness of the nomogram, a decision curve analysis (DCA) was performed.Tumor shape, boundary, and enhancement features were independent predictors of meningioma venous sinus invasion (p = 0.013, p = 0.013, p = 0.005, respectively). Eleven (T2:1, T1C:4, DWI:6) of the 3948 radiomics features were screened for strong association with meningioma sinus invasion. The areas under the ROC curves for the training and external test sets were 0.946 and 0.874, respectively. The clinicoradiomic model showed excellent predictive performance for invasive meningioma, which may help to guide surgical approaches and predict prognosis.

Meningiomas with CNS invasion.

CNS invasion has been included as an independent criterion for the diagnosis of a high-grade (WHO and CNS grade 2 and 3) meningioma in the 2016 and more recently in the 2021 WHO classification. However, the prognostic role of brain invasion has recently been questioned. Also, surgical treatment for brain invasive meningiomas may pose specific challenges. We conducted a systematic review of the 2016-2022 literature on brain invasive meningiomas in Pubmed, Scopus, Web of Science and the Cochrane Library. The prognostic relevance of brain invasion as a stand-alone criterion is still unclear. Additional and larger studies using robust definitions of histological brain invasion and addressing the issue of sampling errors are clearly warranted. Although the necessity of molecular profiling in meningioma grading, prognostication and decision making in the future is obvious, specific markers for brain invasion are lacking for the time being. Advanced neuroimaging may predict CNS invasion preoperatively. The extent of resection (e.g., the Simpson grading) is an important predictor of tumor recurrence especially in higher grade meningiomas, but also - although likely to a lesser degree - in benign tumors, and therefore also in brain invasive meningiomas with and without other histological features of atypia or malignancy. Hence, surgery for brain invasive meningiomas should follow the principles of maximal but safe resections. There are some data to suggest that safety and functional outcomes in such cases may benefit from the armamentarium of surgical adjuncts commonly used for surgery of eloquent gliomas such as intraoperative monitoring, awake craniotomy, DTI tractography and further advanced intraoperative brain tumor visualization.

Atypical invasive secondary meningioma with extensive intracranial invasion: A case report

Invasive and metastatic version of meningioma as an atypical type of the tumor has been rarely described in the literatures. Recurrent secondary meningioma invaded to pre-orbital soft and hard tissues can be found in extremely rare cases. We described a case of atypical invasive meningioma invaded to deep orbital soft tissue due to recurrence of the primary tumor previously treated by surgical removing and chemoradiotherapy. In this case, invasion to orbit, paranasal sinuses and masticator, infratemporal and buccal spaces leading to destruction of adjacent bony structures and mass engulfing the right globe resulting in considerable proptosis was the prominent feature.

DELAYED CEREBRAL VENOUS SINUS THROMBOSIS (CSVT) AFTER AN INVASIVE MENINGIOMA RESECTION: AN UNCOMMON PRESENTATION OF A COMMON COMPLICATION

DELAYED CEREBRAL VENOUS SINUS THROMBOSIS (CSVT) AFTER AN INVASIVE MENINGIOMA RESECTION: AN UNCOMMON PRESENTATION OF A COMMON COMPLICATION

Microsurgical technique for en bloc anatomical exenteration of cavernous sinus compartment to treat invasive meningioma

BackgroundMeningioma is the most common tumour originating in the cavernous sinus (CS). Despite treatment with microsurgery, radiation, or a combination of both, some meningiomas of the CS (CSM) may recur and show invasive growth and progression with neurological deficits and cerebrovascular insufficiency. ObjectiveTo present an anatomical microsurgical CS en bloc exenteration (EBCSE) technique for selected patients with CSM. MethodsAn anatomical laboratory study was conducted using three heads. The heads were fixed using formalin solution and the arteries and veins were injected with silicone. EBCSE was performed under the surgical microscope. A high flow bypass was also carried out using a saphenous venous graft from the same specimen. The clinical study included three patients with recurrent CSM undergoing EBCSE following the technique described in this paper. ResultsOur surgical technique for EBCSE consists of five steps: middle fossa approach to the lateral wall of the CS, high-flow bypass, anatomical identification and step-by-step section of the CS limits, en bloc CS and tumour exenteration and, finally, reconstruction. The CS compartment was completely removed in all patients, with gross total resection (GTR) of the CSM, and without major postoperative complications or significant functional decline. ConclusionsIn selected patients with CSM, GTR can be achieved with acceptable results. EBCSE involves the sacrificing the internal carotid artery and all the CS cranial nerves. A bypass, preferably high-flow, should be performed to prevent cerebral ischemia.

LncRNA-IMAT1 Promotes Invasion of Meningiomas by Suppressing KLF4/hsa-miR22-3p/Snai1 Pathway.

Malignant meningiomas often show invasive growth that makes complete tumor resection challenging, and they are more prone to recur after radical resection. Invasive meningioma associated transcript 1 (IMAT1) is a long noncoding RNA located on Homo sapiens chromosome 17 that was identified by our team based on absolute expression differences in invasive and non-invasive meningiomas. Our studies indicated that IMAT1 was highly expressed in invasive meningiomas compared with non-invasive meningiomas. In vitro studies showed that IMAT1 promoted meningioma cell invasion through the inactivation of the Krüppel-like factor 4 (KLF4)/hsa-miR22-3p/Snai1 pathway by acting as a sponge for hsa-miR22-3p, and IMAT1 knockdown effectively restored the tumor suppressive properties of KLF4 by preserving its tumor suppressor pathway. In vivo experiments confirmed that IMAT1 silencing could significantly inhibit the growth of subcutaneous tumors and prolong the survival period of tumor-bearing mice. Our findings demonstrated that the high expression of IMAT1 is the inherent reason for the loss of the tumor suppressive properties of KLF4 during meningioma progression. Therefore, we believe that IMAT1 may be a potential biological marker and treatment target for meningiomas.

Hyperostotic Invasive Meningioma of the Sphenoid Ridge Surgical Considerations: 2-Dimensional Operative Video.

Hyperostotic invasive sphenoid ridge meningiomas are a distinct and recognized entity.1-4 They are characterized by extensive bone involvement and expansive “en plaque” intradural extension.3,5 The goal of this surgery is improving and preserving the visual function and ocular motility while esthetically correcting and reconstructing the exophthalmos and temporal deformity.4,5 The surgery includes radical removal of the involved bone of the sphenoid ridge, orbital walls, and middle fossa floor, in addition to the “en plaque” dural and periorbital involvement and intradural extension.3,5,6 Early decompression of the optic nerve and orbital elements allows preventing visual function deterioration and yields frequent improvement. Thorough planned reconstruction can be achieved by molding a malleable mesh to the patient's skull before the extensive bone removal. Careful orbital wall reconstruction allows one to achieve a good postoperative cosmesis and prevent enophthalmos.4 We demonstrate the principles of this surgery through 2 cases of 46-year-old and 53-year-old women. The first case demonstrates the importance of middle fossa extensive drilling of involved bone and reconstruction while the second case demonstrates the visual decompression and postoperative improvement. The patients consented to the surgeries and publication of their images.

Predictive Factors of Postoperative Peritumoral Brain Edema after Meningioma Resection

Postoperative peritumoral brain edema (PTBE) is the progressively exacerbating cerebral edema following meningiomas resection. The study aims to identify the predictive factors of postoperative PTBE. A retrospective study was conducted on the 117 cases of patients who underwent meningioma. The histopathological features of the tumors were re-assessed according to WHO 2016 classification. Clinical and pathohistological features were analyzed. Thirteen patients (11.1%) were diagnosed having postoperative PTBE. Preoperative seizure (odds ratio [OR] = 6.125, P = 0.039) and histological prominent nucleoli (OR = 3.943, P = 0.039) were the independent risk factors for postoperative PTBE. Meningiomas with a parietal localization were more likely to develop postoperative PTBE (OR = 3.576, P = 0.054). Brain invasion and large tumor volume did not increase complication rate. Preoperative edema index was significantly higher in brain invasive meningiomas (3.0 ± 2.2 versus 1.8 ± 1.7, P = 0.001). Patients having moderate preoperative PTBE were prone to the complication (21.4% versus 7.9%, P = 0.100). Preoperative seizure were the predictive factors for postoperative PTBE. Careful venous protection during the operation may be helpful, especially for tumors locating in the parietal lobe. Prominent nucleoli observed in postoperative pathology should warrant surgeons' attention. Comprehensive perioperative management is essential for these patients.

Comprehensive overview of extracellular vesicle proteomics in meningioma: future strategy.

BackgroundMeningioma arising from meninges is one among the various types of brain tumors. Others are, astrocytomas originating from astrocyte, oligodendrogliomas originating from oligodendrocyte, Ependymomas originating from ependymal cells and medulloblastomas originating from neurons. Current knowledge of molecular biology, genetics and epigenetics of meningioma is not sufficient. Therefore, In depth understanding of the mechanism of meningioma formation and progression is needed for its treatment and management. Grade I Grade I meningiomas are majorly classified as grade I, grade II and grade III. Meningioma can be indolent, slow growing or can be invasive and metastatic which can recurre. Grade I meningioma can be removed by surgery in comparison to invasive meningioma which may recurre with high propensity. This property of recurrence is responsible for high morbidity and mortality. Meningioma are majorly classified into three classes namely grade I, grade II, grade III. Protein biomarkers are considered as promising candidates for the diagnosis of meningioma.StudyVarious studies done on differential expression of proteins have shown increased expression of EGFR, NEK9, EPS812, CKAP4, SET and STAT2, in all the three grades of meningioma. Additionally, some proteins like HK2 are overexpressed in grade II and grade III meningioma than in grade I meningioma. Protein Markers, found on extracellular vesicles of different grades of meningioma can serve the same purpose. A test done on a sample of any kind of body fluid like blood, tear, saliva, urine etc. for recognizing the circulating cancer cells or DNA and extracellular vesicles released from them to help detecting the early stage of cancer is known as liquid biopsy. Solid biopsy has several limitations as compared to liquid biopsy. This is because the samples can be easily collected and studied in case of liquid biopsy. Exosomes are related with liquid biopsy and hence provide platform for better diagnosis, prognosis and treatment of any type of cancer including meningioma. Exosomal tetraspanin are important example of exosomal biomarkers. The tetraspanin network is a molecular scaffold which connects various proteins for signal transduction.ConclusionThis study tells about the utility of proper knowledge of extracellular vesicle proteins and their profiles in different grades, which can help in better understanding of pathogenesis, diagnosis, prognosis and treatment of meningioma. In Addition to use of these proteins as biomarkers, role of exosomes in currently available therapeutic approaches has been discussed.

Meningioma-Brain Crosstalk: A Scoping Review.

Background: In recent years, it has become evident that the tumoral microenvironment (TME) plays a key role in the pathogenesis of various cancers. In meningiomas, however, the TME is poorly understood, and it is unknown if glia cells contribute to meningioma growth and behaviour. Objective: This scoping review investigates if the literature describes and substantiates tumour-brain crosstalk in meningiomas and summarises the current evidence regarding the role of the brain parenchyma in the pathogenesis of meningiomas. Methods: We identified studies through the electronic database PubMed. Articles describing glia cells and cytokines/chemokines in meningiomas were selected and reviewed. Results: Monocytes were detected as the most abundant infiltrating immune cells in meningiomas. Only brain-invasive meningiomas elicited a monocytic response at the tumour-brain interface. The expression of cytokines/chemokines in meningiomas has been studied to some extent, and some of them form autocrine loops in the tumour cells. Paracrine interactions between tumour cells and glia cells have not been explored. Conclusion: It is unknown to what extent meningiomas elicit an immune response in the brain parenchyma. We speculate that tumour-brain crosstalk might only be relevant in cases of invasive meningiomas that disrupt the pial-glial basement membrane.

Diagnosis of Invasive Meningioma Based on Brain-Tumor Interface Radiomic Features with a Width of 4mm on Brain Mr Images: A Multicenter Study

Background: Meningioma invasion can be pre-operatively recognized by radiomic features, which significantly contributes to treatment decision-making. Here, we aimed to evaluate the comparative performance of radiomic signatures derived from varying regions of interests(ROIs) in predicting BI and ascertaining the optimal width of the peritumoral regions needed for accurate analysis. Methods: 505 patients from Wuhan Union Hospital (internal cohort) and 214 cases from Taihe Hospital (external validation cohort) that pathologically diagnosed as meningioma were included in our study. Feature selection was performed from 1015 radiomic features respectively obtained from nine different ROIs[brain-tumor interface(BTI)2-5mm; whole tumor; the amalgamation of the two regions] on contrast-enhancement T1-weighted imaging using least absolute shrinkage and selection operator and random forest. Principal component analysis with varimax-rotation was employed for feature reduction. Receiver operator curve was utilized for assessing discrimination of the classifier. Furthermore, clinical index was used to detect the predictive power. Findings: Model obtained from BTI4mm ROI has the maximum AUC in the training set (0.98(0.97-0.99)), internal validation set (0.97(0.93-1)), and external validation set (0.72(0.62-0.81)) and displayed statistically significant results between nine radiomics models. The most predictive radiomic features are almost entirely generated from GLCM and GLDM statistics. The addition of PEV to radiomic features(BTI4mm) enhanced model discrimination of invasive meningiomas. Interpretation: The combined model(radiomic classifier with BTI4mm ROI + PEV) had greater diagnostic performance than other models, and may contribute to clinical application for meningioma patients. Funding: This study has received funding from National Natural Science Foundation of China (81974390). Declaration of Interest: The authors declare no potential conflicts of interest. Ethical Approval: The Wuhan Union Hospitals' Ethics Committees approved this research (NO. 2021-0098-01).

Immunohistochemical expression of matrix metalloproteinase -9 in invasive meningioma

Background: Meningioma is a common intracranial tumor arising from the meningothelial (arachnoid) cells. Meningiomas are divided into 15 histological subtypes and three grades, including benign (grade I), atypical (grade II) and anaplastic (grade III). It is important to correctly decide whether a meningioma isbrain-invasive or not. Tumor invasion can be described as a stepwise process involving the degradation of the extracellular matrix (ECM), tumor cell adhesion to resident cells or components, increased proliferation, and cell migration into new intracellular/ECM space. It is believed that expression of Matrix metalloproteinases (MMPs) can be related with this process, especially the matrix metalloproteinase-9 (MMP9). Objectives: Investigation of matrix metalloproteinase-9 expression in different grades of meningioma and correlate this expression with brain invasion. Patients and methods: Matrix metalloproteinase-9 immunostaining was studied in 50 specimens of meningioma using avidin-biotin peroxidase method. Results: The percentage of brain invasive was 5% as regard to MMP9 score 1 ,5% as regard MMP9 score 2,20% as regard MMP9 score 3,70% as regard MMP9 score 4. A significant positive correlation was found between MMP9score and brain invasion (p < 0.001). Conclusion: Increased MMP9 expression is correlated with brain invasion.

Invasive Recurrent Meningioma with Extracranial Tissue Involvement: A Case Report

Meningioma is a common benign intracranial neoplasm. The incidence of extracranial extension to other sites is rare. Due to the neglected intracranial component, the chances of an under diagnosis or a misdiagnosis of the extracranial component is there, which may adversely affect the management and therefore, the prognosis of the patient.

An allele of rs619586 polymorphism in MALAT1 alters the invasiveness of meningioma via modulating the expression of collagen type V alpha (COL5A1).

The rs619586 polymorphism has been shown to alter the expression of MALAT1, which act as a competing endogenous RNA (ceRNA) against miR‐145. And miR‐145 was found to target COL5A1, the interaction between which was shown to be involved in the pathogenesis of invasive meningioma. In this study, we aimed to explore the effect of rs619586 polymorphism and its underlying molecular mechanism in invasive meningioma. Real‐time PCR and Western Blot analysis were used to study the differentiated expression of miR‐145, MALAT1 (metastasis‐associated lung adenocarcinoma transcript 1) and COL5A1 (collagen alpha‐1(V) chain) in tumour/serum samples genotyped as rs619586 AA, AG and GG. Computational analysis and luciferase reporter assay were also conducted to identify the regulatory relationship between miR‐145 and MALAT1/COL5A1. Meanwhile, expression of miR‐145 and COL5A1 in different cell treatment groups was measured to validate the results obtained from earlier experiments. As shown by the results and in tumour/serum samples genotyped as AA, AG and GG, the expression of both MALAT1 and COL5A1 was down‐regulated in a stepwise fashion, while the expression of miR‐145 was increased, suggesting a potential negative relationship between MALAT1/COL5A1 and miR‐145. Meanwhile, miR‐145 was shown to bind to MALAT1, while COL5A1 was identified as a virtual target gene of miR‐145. As a consequence, a MALAT1/miR‐145/COL5A1 molecular pathway was established based on the above results. In particular, with the presence of rs619586 A>G polymorphism, the expression of MALAT1 and COL5A1 was both reduced, leading to reduced invasiveness of meningioma.

Lack of Correlation Between Immunohistochemical Expression of SPARC and Invasion in Different Grades of Meningiomas.

Grade I meningiomas are generally benign and non-invasive whereas Grade II (atypical) and Grade III (malignant) meningiomas tend to be invasive with a high risk of recurrence. SPARC, secreted protein, acidic and rich in cysteine, is a multifunctional glycoprotein which has been proposed to be a potential diagnostic marker of invasive meningiomas. There has been increased reporting of atypical meningiomas since the current World Health Organization (WHO) included brain invasion as a grading criterion for classification of these particular meningiomas. The aim of this study was to re-evaluate any correlation between immunohistochemical expression of SPARC in 34 meningiomas of various grades using the current classification (2016). We had previously classified these cases using the 2002 WHO criteria. There is no correlation between expression of SPARC and invasion in different grades of meningioma. SPARC does not appear to be a good predictor of invasion in meningiomas.

The effect of the revised WHO classification on the incidence of grade II meningioma

Introduction: A retrospective study over a three-year period at University Hospital of Wales (UHW) of the incidence of atypical cranial grade II meningioma both pre and post 2016 revision of The World Health Organisation (WHO) classification of tumours of the central nervous system.Subjects: All available histology from January 2015 to December 2017 of patients with cranial meningiomas.Method: Institutional online reporting system Welsh Clinical Portal to identify patients and view histology reports.Results: Overall 164 patient histology results were analysed (median age 59, age range 23-82, 74% females). There were 55 patients in 2015: 69.1% grade I, 29.1% grade II and 1.8% grade III. There were 109 patients in 2016/17; 68.8% grade I, 29.4% grade II, 1.8% grade III.Discussion: There is significant variability in the reported incidence of grade II meningioma, likely due to variation in local interpretation of diagnostic criteria. Neuropathologists at our institution have reported brain invasion as grade II prior to 2016. This was due to compelling published evidence that brain invasive meningiomas have recurrence and mortality rates similar to that of grade II meningioma as defined using other criteria. The new 2016 WHO criteria now recognise this specifically. As other institutions adapt to the amended 2016 guidelines we anticipate that there will be a greater consensus in line with our incidence rates of grade II meningioma.

Brain invasion and the risk of seizures in patients with meningioma.

Identification of risk factors for perioperative epilepsy remains crucial in the care of patients with meningioma. Moreover, associations of brain invasion with clinical and radiological variables have been largely unexplored. The authors hypothesized that invasion of the cortex and subsequent increased edema facilitate seizures, and they compared radiological data and perioperative seizures in patients with brain-invasive or noninvasive meningioma. Correlations of brain invasion with tumor and edema volumes and preoperative and postoperative seizures were analyzed in univariate and multivariate analyses. Totals of 108 (61%) females and 68 (39%) males with a median age of 60 years and harboring totals of 92 (52%) grade I, 79 (45%) grade II, and 5 (3%) grade III tumors were included. Brain invasion was found in 38 (22%) patients and was absent in 138 (78%) patients. The tumors were located at the convexity in 72 (41%) patients, at the falx cerebri in 26 (15%), at the skull base in 69 (39%), in the posterior fossa in 7 (4%), and in the ventricle in 2 (1%); the median tumor and edema volumes were 13.73 cm3 (range 0.81-162.22 cm3) and 1.38 cm3 (range 0.00-355.80 cm3), respectively. As expected, edema volume increased with rising tumor volume (p < 0.001). Brain invasion was independent of tumor volume (p = 0.176) but strongly correlated with edema volume (p < 0.001). The mean edema volume in noninvasive tumors was 33.0 cm3, but in invasive tumors, it was 130.7 cm3 (p = 0.008). The frequency of preoperative seizures was independent of the patients' age, sex, and tumor location; however, the frequency was 32% (n = 12) in patients with invasive meningioma and 15% (n = 21) in those with noninvasive meningioma (p = 0.033). In contrast, the probability of detecting brain invasion microscopically was increased more than 2-fold in patients with a history of preoperative seizures (OR 2.57, 95% CI 1.13-5.88; p = 0.025). In univariate analyses, the rate of preoperative seizures correlated slightly with tumor volume (p = 0.049) but strongly with edema volume (p = 0.014), whereas seizure semiology was found to be independent of brain invasion (p = 0.211). In multivariate analyses adjusted for age, sex, tumor location, tumor and edema volumes, and WHO grade, rising tumor volume (OR 1.02, 95% CI 1.00-1.03; p = 0.042) and especially brain invasion (OR 5.26, 95% CI 1.52-18.15; p = 0.009) were identified as independent predictors of preoperative seizures. Nine (5%) patients developed new seizures within a median follow-up time of 15 months after surgery. Development of postoperative epilepsy was independent of all clinical variables, including Simpson grade (p = 0.133), tumor location (p = 0.936), brain invasion (p = 0.408), and preoperative edema volume (p = 0.081), but was correlated with increasing preoperative tumor volume (p = 0.004). Postoperative seizure-free rates were similar among patients with invasive and those with noninvasive meningioma (p = 0.372). Brain invasion was identified as a new and strong predictor for preoperative, but not postoperative, seizures. Although also associated with increased peritumoral edema, seizures in patients with invasive meningioma might be facilitated substantially by cortical invasion itself. Consideration of seizures in consultations between the neurosurgeon and neuropathologist can improve the microscopic detection of brain invasion.