Meningioma: a cytogenetic model of a complex benign human tumor, including data on 394 karyotyped cases

Risk factors on surgical compliance and its impact on survival outcomes in meningioma patients: a SEER-based retrospective propensity-score matched analysis

BACKGROUND

This study aimed to analyze the effect of surgical compliance on the survival outcome of patients with meningioma and explore the factors affecting surgical compliance.

METHODS

We selected data from the Surveillance, Epidemiology, and End Results database for 122,632 meningioma patients diagnosed between 2004 and 2018. The effect of surgical compliance on patients' overall survival (OS) was analyzed through Cox regression and Kaplan-Meier curves. Independent risk factors for surgical compliance were identified through multifactorial logistic regression analyses to construct diagnostic nomograms, further assessed by receiver operating characteristic curves. Furthermore, we used univariate and multivariate logistic regression analyses to evaluate relevant variables linked to adherence with meningioma surgery. Moreover, 1:1 propensity score matching was applied to assess the validity of the results in patients with favorable and poor surgical compliance.

RESULTS

A total of 48,735 were eligible from the initial cohort of 122,632 patients with meningioma. Among them, 45,038 (92.40%) exhibited good surgical compliance, while 3697 (7.60%) had poor surgical compliance. The rate of patients with good surgical compliance was significantly higher than that of patients with inadequate surgical compliance (p < 0.001). Moreover, surgical compliance is an independent prognostic factor for OS in meningioma patients. Univariate Cox regression analysis indicated that individuals with poor surgical compliance demonstrated lower OS rates than those with good surgical compliance (hazard ratio [HR 2.404; 95% confidence interval [CI] 2.276-2.54, p < 0.001], consistent with the observation in the multivariate analysis (HR 1.564; 95% CI 1.471-1.663, p < 0.001). We developed a prediction model using seven variables: age, sex, race, tumor behavior recode, tumor size, family income, and residential setting (p < 0.05). Surgical compliance was associated with patient age, sex, race, tumor behavior recode, tumor size, family income, and residential setting by logistic regression analysis.

CONCLUSIONS

Surgical compliance emerged as an independent prognostic factor for survival in patients with meningioma. Poor surgical compliance was associated with older age, black and other races, females, advanced-stage tumors, larger tumor size, lower household income, and rural residence. When patients experienced these conditions, OS was shorter, requiring more aggressive treatment.

Multiple ossified intracranial and spinal meningiomas: a rare case report and literature review

Ossified intracranial meningiomas (OIM) and ossified spinal meningiomas (OSM) are rare neoplasms of mesenchymal origin that predominantly manifest in the spinal cord and infrequently in the cranial region, accounting for ~0. 7-5.5% of all meningiomas. It is extremely rare to have multiple intracranial and spinal lesions accompanied by ossification. Herein, we report this rare case for the first time. A 34-year-old woman presented with paresthesia and limb weakness in the right lower limb and gradually worsened. Approximately half a year later, she could only walk with crutches. Magnetic resonance imaging of the brain and spinal cord showed multiple meningiomas, and histopathological examination confirmed multiple OIM and OSM (WHO grade 1). Multiple OIM and OSM are extremely rare with diverse imaging features, and it is easily confused with other tumors. Histopathological examination is the final diagnostic method.

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.

Signaling pathways in brain tumors and therapeutic interventions

Brain tumors, although rare, contribute to distinct mortality and morbidity at all ages. Although there are few therapeutic options for brain tumors, enhanced biological understanding and unexampled innovations in targeted therapies and immunotherapies have considerably improved patients' prognoses. Nonetheless, the reduced response rates and unavoidable drug resistance of currently available treatment approaches have become a barrier to further improvement in brain tumor (glioma, meningioma, CNS germ cell tumors, and CNS lymphoma) treatment. Previous literature data revealed that several different signaling pathways are dysregulated in brain tumor. Importantly, a better understanding of targeting signaling pathways that influences malignant behavior of brain tumor cells might open the way for the development of novel targeted therapies. Thus, there is an urgent need for a more comprehensive understanding of the pathogenesis of these brain tumors, which might result in greater progress in therapeutic approaches. This paper began with a brief description of the epidemiology, incidence, risk factors, as well as survival of brain tumors. Next, the major signaling pathways underlying these brain tumors' pathogenesis and current progress in therapies, including clinical trials, targeted therapies, immunotherapies, and system therapies, have been systemically reviewed and discussed. Finally, future perspective and challenges of development of novel therapeutic strategies in brain tumor were emphasized.

Genomic Landscape of Meningiomas

Despite being the most common primary brain tumor in adults, until recently, the genomics of meningiomas have remained quite understudied. In this chapter we will discuss the early cytogenetic and mutational changes uncovered in meningiomas, from the discovery of the loss of chromosome 22q and the neurofibromatosis-2 (NF2) gene to other non-NF2 driver mutations (KLF4, TRAF7, AKT1, SMO, etc.) discovered using next generation sequencing. We discuss each of these alterations in the context of their clinical significance and conclude the chapter by reviewing recent multiomic studies that have integrated our knowledge of these alterations together to develop novel molecular classifications for meningiomas.

Benign Spinal Tumors

Benign spinal intradural tumors are relatively rare and include intramedullary tumors with a favorable histology such as low-grade astrocytomas and ependymomas, as well as intradural extramedullary tumors such as meningiomas and schwannomas. The effect on the neural tissue is usually a combination of mass effect and neuronal involvement in cases of infiltrative tumors. The new understanding of molecular profiling of different tumors allowed us to better define central nervous system tumors and tailor treatment accordingly. The mainstay of management of many intradural spinal tumors is maximal safe surgical resection. This goal is more achievable with intradural extramedullary tumors; yet, with a meticulous surgical approach, many of the intramedullary tumors are amenable for safe gross-total or near-total resection. The nature of these tumors is benign; hence, a different way to measure outcome success is pursued and usually depends on functional rather than oncological or survival outcomes.

Incidence and Survival of Benign, Borderline, and Malignant Meningioma Patients in the United States from 2004 to 2018

Meningioma is the most common primary central nervous system tumor, and its incidence is increasing. A systematic epidemiological and clinical analysis is required to better estimate its public health impact and understand its prognostic factors. Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2018 for all types of meningiomas without an age restriction. Age-adjusted incidence rates (IRs) and 95% confidence intervals were estimated according to sex, age, race, ethnicity, and tumor location. Kaplan-Meier analysis and multivariate Cox proportional hazard models were used to analyze the overall survival (OS). The competing risk regression model of Fine-Gray was used to analyze cause-specific survival. Data from a total of 109,660 meningioma patients were analyzed. A majority of patients were older than 60 years, and only 0.41% of patients were 0-19 years. The meningioma IRs were higher in females, Black, and non-Hispanic patients than in males, White, and Hispanic patients, respectively, and IRs increased with age. The ratio of IRs for females to males was 2.1 and also increased with age, peaking at 3.6 in the 45-49-year-old group. Older and male patients with all types of meningiomas, Black patients with benign and borderline meningiomas, and patients with larger borderline and malignant meningiomas showed poorer prognosis. For all meningioma types, surgical resection improved survival. The reported incidence rates and survival trends covered all demographics and subtypes of meningiomas. Older age, male sex, Black race, and tumor size may be important prognostic factors for meningioma cases, and tumor resection can substantially improve survival among meningioma patients.

Bone Invasive Meningioma: Recent Advances and Therapeutic Perspectives

Meningioma is the most common primary neoplasm of the central nervous system (CNS). Generally, these tumors are benign and have a good prognosis. However, treatment can be challenging in cases with aggressive variants and poor prognoses. Among various prognostic factors that have been clinically investigated, bone invasion remains controversial owing to a limited number of assessments. Recent study reported that bone invasion was not associated with WHO grades, progression, or recurrence. Whereas, patients with longer-recurrence tended to have a higher incidence of bone invasion. Furthermore, bone invasion may be a primary preoperative predictor of the extent of surgical resection. Increasing such evidence highlights the potential of translational studies to understand bone invasion as a prognostic factor of meningiomas. Therefore, this mini-review summarizes recent advances in pathophysiology and diagnostic modalities and discusses future research directions and therapeutic strategies for meningiomas with bone invasion.

Clinical Significance of Molecular Alterations and Systemic Therapy for Meningiomas: Where Do We Stand?

Simple Summary

Meningiomas are the most frequent intracranial tumors and comprise a heterogeneous spectrum of diseases, ranging from small, asymptomatic tumors that do not need treatment to large, symptomatic ones causing seizures or neurological deficits that require surgery and/or radiotherapy. Systemic therapy is reserved for progressive or recurrent meningiomas when surgery and/or radiotherapy options have been exhausted, with only modest activity in terms of disease control and survival. Novel molecular alterations are correlated with grading, location, and prognosis of meningiomas. Moreover, some of these driver alterations regulate meningioma growth and progression and may be targeted by specific drugs that are under investigation in clinical trials. Lastly, the microenvironment surrounding meningiomas may also contribute to regulating tumor growth: in particular, PD-L1 and/or M2 macrophage expression may represent a target for immunotherapy.

Abstract

Meningiomas are common intracranial tumors that can be treated successfully in most cases with surgical resection and/or adjuvant radiotherapy. However, approximately 20% of patients show an aggressive clinical course with tumor recurrence or progressive disease, resulting in significant morbidity and increased mortality. Despite several studies that have investigated different cytotoxic agents in aggressive meningiomas in the past several years, limited evidence of efficacy and clinical benefit has been reported thus far. Novel molecular alterations have been linked to a particular clinicopathological phenotype and have been correlated with grading, location, and prognosis of meningiomas. In this regard, SMO, AKT, and PIK3CA mutations are typical of anterior skull base meningiomas, whereas KLF4 mutations are specific for secretory histology, and BAP1 alterations are common in progressive rhabdoid meningiomas. Alterations in TERT, DMD, and BAP1 correlate with poor outcomes. Moreover, some actionable mutations, including SMO, AKT1, and PIK3CA, regulate meningioma growth and are under investigation in clinical trials. PD-L1 and/or M2 macrophage expression in the microenvironment provides evidence for the investigation of immunotherapy in progressive meningiomas.

Diagnostic, therapeutic, and prognostic implications of the 2021 World Health Organization classification of tumors of the central nervous system

The 2016 revised fourth edition of the World Health Organization (WHO) classification of central nervous system (CNS) tumors incorporated molecular features with histologic grading, revolutionizing how oncologists conceptualize primary brain and spinal cord tumors as well as providing new insights into their management and prognosis. The 2021 revised fifth edition of the WHO classification further integrates molecular alterations for CNS tumor categorization, updating current understanding of the pathophysiology of many of these disease entities. Here, the authors review changes in the new classification for the most common primary adult tumors-gliomas (including astrocytomas, oligodendrogliomas, and ependymomas) and meningiomas-highlighting the key genomic alterations for each group classification to help clinicians interpret them as they consider therapeutic options-including clinical trials and targeted therapies-and discuss the prognosis of these tumors with their patients. The revised, updated 2021 WHO classification also further integrates molecular alterations in the classification of pediatric CNS tumors, but those are not covered in the current review.

The Role of MicroRNA 181d as a Possible Biomarker Associated With Tumor Progression in Meningiomas

Introduction

Meningiomas are slow-growing intracranial neoplasms that originate from arachnoid meningothelial cells and represent 13-26% of intracranial tumors, thus being the most common. There are numerous technological advances available for a better understanding of the molecular pathways correlated with tumorigenesis and tumor progression of meningiomas. In this context, the role of microRNAs (miRNAs), which are non-coding RNAs (ncRNAs) consisting of 18 to 25 nucleotides whose function is the silencing of mRNA at the posttranscriptional level, has been highlighted. Recent studies suggest that miRNAs may act as possible biomarkers as well as therapeutic targets for various diseases, including brain tumors. Therefore, the objective of our study was to evaluate the tissue and plasma expression of the miRNAs miR-181d, miR-181c, and miR-130a.

Methods

The miRNAs miR-181d, miR-181c, and miR-130a were selected from our group’s prior study by the large-scale microarray analysis technique. In this work, the expression of these miRNAs in the tumor tissue and plasma of patients with grade I (16 patients), II (16 patients), and III (eight patients) meningiomas was evaluated.

Results

MiR-181d was overexpressed in both tumor tissue and plasma in the studied groups. The level of expression was higher according to the progression of tumor grade. MiR-181c and miR-130a showed no significant difference in the studied groups in either tumor tissue or plasma.

Conclusions

MiR-181d has potential as a biomarker for meningiomas and is associated with the tumor progression of meningiomas.

Influence of Human Telomerase Reverse Transcriptase Mutation on the Aggressiveness and Recurrence in Meningiomas

Background: Over 200 human telomerase reverse transcriptase (hTERT) polymorphism combinations have been implicated in the development of cancer. This study aimed to evaluate hTERT mutations in meningioma tissue and its association with meningioma.

Material and Methods: A total of 90 patients who underwent surgery between 2006 and 2015 and were histopathologically diagnosed with meningioma (WHO 2016) were included.

Results: Among the 90 participants included herein, 50 (55.5%) and 40 (44.5%) were female and male, respectively, with an average age of 56.2 ± 14 years. Mean Ki-67 values were 10.56% (SD 12.41, range 0-60), while the mean follow-up duration was 39.1 months (SD 26.3). Low- and high-grade patients had a mean Ki-67 score of 4.31% (SD 3.58, range 0-16) and 19.92% (SD 14.91, range 2-60) (p = 0.0001). Our results showed a moderate positive correlation between Ki-67 score and the presence of hTERT mutation (Pearson correlation test, r = 0.5161; p = 0.0001). Patients with an hTERT mutation > 30% had significantly higher risk for reoperation than those with lower levels of mutation (p = 0.016, chi square test). None of the patients requiring reoperation had an hTERT mutation < 10%. Moreover, high-grade patients had a 7.2 times higher risk of reoperation than those with an hTERT mutation > 30%.

Conclusion: The presence of hTERT mutation, in addition to high Ki-67, indicated a more aggressive meningioma disease course and potentially increased risk of recurrence.

Molecular Profiling of 22 Primary Atypical Meningiomas Shows the Prognostic Significance of 18q Heterozygous Loss and CDKN2A/B Homozygous Deletion on Recurrence-Free Survival

The use of adjuvant therapy is controversial in atypical meningiomas with gross total resection. Predictors of recurrence risk could be useful in selecting patients for additional treatments. The aim of this study was to investigate whether molecular features are associated with recurrence risk of atypical meningiomas. According to WHO classification, the diagnosis of atypical meningioma was based on the presence of one major criteria (mitotic activity, brain invasion) or three or more minor criteria. The molecular profile of 22 cases (eight mitotically active, eight brain-invasive, and six with minor criteria) was assessed exploring the mutational status and copy number variation of 409 genes using next generation sequencing. Of the 22 patients with a median follow up of 53.5 months, 13 had recurrence of disease within 68 months. NF2 mutation was the only recurrent alteration (11/22) and was unrelated to clinical-pathological features. Recurring meningiomas featured a significantly higher proportion of copy number losses than non-recurring ones (p = 0.027). Chromosome 18q heterozygous loss or CDKN2A/B homozygous deletion was significantly associated with shorter recurrence-free survival (p = 0.008; hazard ratio: 5.3). Atypical meningiomas could be tested routinely for these genetic alterations to identify cases for adjuvant treatment.

Meningiomas from a developmental perspective: exploring the crossroads between meningeal embryology and tumorigenesis

Meningiomas are tumors arising from the meninges and represent the most frequent central nervous system tumors in adults. Recent large-scale genetic studies and preclinical meningioma mouse modelling led to a better comprehension of meningioma development and suggested evidences of close relationships between meningeal embryology and tumorigenesis. In this non-systematic review, we summarize the current knowledge on meningeal embryology and developmental biology, and illustrate how meningioma tumorigenesis is deeply related to meningeal embryology, concerning the potential cell of origin, the role of reactivation of embryonic stem cells, the influence of the embryonic tissue of origin, and the parallelism between topography-dependant molecular pathways involved in normal meninges and in meningioma development. Our study emphasizes why future studies on meningeal embryology are mandatory to affine our comprehension of mechanisms underlying meningioma initiation and development.

Gross and Histological Examination of a Large Spheno-Orbital Meningioma

Meningiomas arise from arachnoid cap cells and are the most common heavily researched intracranial tumors. Most of these neoplasms are benign and are classified as World Health Organization (WHO) grade I. They are often found in parasagittal and falx regions, over cerebral convexities, and in the sphenoid ridges. Spheno-orbital meningiomas (SOMs) occupy the cranium and the orbit and are less commonly encountered. Nonetheless, in this case study, a 9.5 cm × 5 cm SOM occurring in a 93-year-old female cadaver was identified and examined. The tumor spanned from the left middle cranial fossa, through the anterior fossa and invaded the orbit. It caused proptosis of the left eye, compression of the temporal lobe, and damage to the optic nerve. Histological examination of the tumor revealed characteristics of a WHO grade I meningothelial meningioma.

Molecular and translational advances in meningiomas

Meningiomas are the most common primary intracranial neoplasm. The current World Health Organization (WHO) classification categorizes meningiomas based on histopathological features, but emerging molecular data demonstrate the importance of genomic and epigenomic factors in the clinical behavior of these tumors. Treatment options for symptomatic meningiomas are limited to surgical resection where possible and adjuvant radiation therapy for tumors with concerning histopathological features or recurrent disease. At present, alternative adjuvant treatment options are not available in part due to limited historical biological analysis and clinical trial investigation on meningiomas. With advances in molecular and genomic techniques in the last decade, we have witnessed a surge of interest in understanding the genomic and epigenomic landscape of meningiomas. The field is now at the stage to adopt this molecular knowledge to refine meningioma classification and introduce molecular algorithms that can guide prediction and therapeutics for this tumor type. Animal models that recapitulate meningiomas faithfully are in critical need to test new therapeutics to facilitate rapid-cycle translation to clinical trials. Here we review the most up-to-date knowledge of molecular alterations that provide insight into meningioma behavior and are ready for application to clinical trial investigation, and highlight the landscape of available preclinical models in meningiomas.

Infarction with associated pseudosarcomatous changes mimics anaplasia in otherwise grade I meningiomas

We describe a morphologically distinct pattern of tumor infarction and associated sarcoma-like changes, mimicking focal anaplasia, in otherwise WHO grade I meningiomas. The described cases (n = 9) all demonstrated a discrete spindle-cell (pseudosarcomatous) component with brisk mitotic activity (12-14 mitoses/10 HPF), elevated Ki-67 (mean 75.5 ± 25.0%, quantified), absence of PR, SSTR2A, or EMA expression, and potential SMA expression (50%). Despite these high-grade features, all nine patients remained free of progression or recurrence post resection (follow-up mean: 49.8 months). In contrast, among a comparison (control) cohort of consecutive WHO grade II and III meningiomas (n = 16), as expected, progression rate was high (68.8%, P = 0.002, Fisher's exact, average time to progression = 25 months, follow-up mean: 39.8 months). While necrosis was a frequent feature among atypical/anaplastic meningiomas (12/16, 75%), and elevated mitoses and proliferative index were present consistent with histologic grade, a well-defined zonal pattern with pseudosarcomatous component was not present among these tumors. DNA methylation-based analysis readily distinguished meningiomas by copy number profiles and DNA-based methylation meningioma random forest classification analysis (meningioma v2.4 classifier developed at University of Heidelberg); all pseudosarcomatous cases analyzed (4/9) matched with high level calibrated classifier score to "MC benign-1", with isolated loss of chromosome 22q identified as the sole copy number alteration. In contrast, multiple chromosomal losses were detected among the comparison cohort and classifier results demonstrated good concordance with histologic grade. Our findings suggest that pseudosarcomatous alterations represent reactive changes to central meningioma infarction, rather than focal anaplasia, and further support the use of DNA methylation-based analysis as a useful adjunct for predicting meningioma behavior. These indolent tumors should be distinguished from their atypical and anaplastic counterparts.

Meningiomas: An Overview of the Landscape of Copy Number Alterations in Samples from an Admixed Population

Meningiomas are considered the most common intracranial tumors, affecting mainly women. Studies in mixed populations can be of great importance to clarify issues related to the genetic diversity of tumors and their development. Considering that data obtained from analyses of the profile of copy number alterations (CNA) have been a useful diagnostic indicator for many types of tumors and that meningiomas show a complex pattern of gains and losses in the number of copies, our objective was to analyze the CNA profile in 33 samples of meningiomas of different histological grades (WHO Grade I-III) from patients in a city located in the Amazon region of Brazil, using aCGH. We found that the female to male ratio was 3 : 1. The aCGH analysis revealed a total of 2304 CNA, with an average of 69.8 ± 57.4 per case, of which 1197 were gains (52%), 926 were losses (40.2%), 105 were amplifications (4. 5%), and 76 were deletions (3.3%). A significant relationship was observed between the type of CNA and the degree of the tumor (chi-square test: χ 2 = 65,844; p < 0.0001; contingency coefficient: C = 0.1772; p < 0.0001). Evaluating the recurrent changes in at least 50% of the samples, we observe as the most frequent losses of the segments 22q13.1-q13.2 (82%), 1p35.3 (76%), and 14q13.1-q13.2 (67%), involving all histopathological grades. The analysis of these regions showed the inclusion of genes with functions such as regulation, maintenance of cell survival, reorganization of the cytoskeleton, cell signaling, and DNA repair, among others. However, overall, the profiles observed in meningiomas of this admixed population were very similar to the ones observed in Caucasian groups. An interesting finding was a recurrent gain of 8p22 observed only in grade I meningiomas, a region which includes DLC1, a suppressor candidate gene probably implicated in the developments or progression of meningiomas, usually found deleted, when related to CNAs.

Molecular Advances in Central Nervous System Mesenchymal Tumors

Mesenchymal tumors of the central nervous system (CNS) comprise an array of neoplasms that may arise from or secondarily affect the CNS and its immediate surroundings. This review focuses on meningiomas and solitary fibrous tumors, the most common primary CNS mesenchymal tumors, and discusses recent advances in unveiling the molecular landscapes of these neoplasms. An effort is made to underscore those molecular findings most relevant to tumor diagnostics and prognostication from a practical perspective. As molecular techniques become more readily used at the clinical level, such alterations may strengthen formal grading schemes and lend themselves to treatment with targeted therapies.

The Essentials of Molecular Testing in CNS Tumors: What to Order and How to Integrate Results

PURPOSE OF REVIEW

Molecular testing has become essential for the optimal workup of central nervous system (CNS) tumors. There is a vast array of testing from which to choose, and it can sometimes be challenging to appropriately incorporate findings into an integrated report. This article reviews various molecular tests and provides a concise overview of the most important molecular findings in the most commonly encountered CNS tumors.

RECENT FINDINGS

Many molecular alterations in CNS tumors have been identified over recent years, some of which are incorporated into the 2016 World Health Organization (WHO) classification and the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official WHO (cIMPACT-NOW) updates. Array-based methylation profiling has emerged over the past couple of years and will likely replace much of currently used ancillary testing for diagnostic purposes. A combination of next-generation sequencing (NGS) panel and copy number array is ideal for diffuse gliomas and embryonal tumors, with a low threshold to employ in other tumor types. With the recent advances in molecular diagnostics, it will be ever more important for the pathologist to recognize the molecular testing available, which tests to perform, and to appropriately integrate results in light of clinical, radiologic, and histologic findings.

The Expression of MIR17HG Protein as a Potential Therapeutic Target in Meningioma

BACKGROUND

MIR17 host gene (MIR17HG) is a potential therapeutic target for some cancer types. The aim of this study was to assess MIR17HG protein levels in patients with meningioma who had not been reported previously in the literature and comparing with normal meninges tissues.

METHODS

MIR17HG protein levels were measured in 46 samples including 25 meningioma tissues procured during surgery and 21 normal meninges tissues obtained within 4 hours of death during autopsy procedures. Each sample was stored at -80°C until the evaluation of MIR17HG protein using a sandwich enzyme-linked immunoassay principle. Results were compared between the groups.

RESULTS

MIR17HG protein levels were significantly higher in meningioma tissues compared with controls and difference was statistically significant (P = 0.012). Both World Health Organization grade I and grade II meningiomas had higher MIR17HG protein levels compared with controls and differences were statistically significant (P = 0.026 for grade I and P = 0.042 for grade II). Receiver operating characteristic curve analysis was performed to determine the cutoff of MIR17HG protein value in differentiating meningioma and control groups. At the cutoff value for MIR17HG protein of >0.0998 ng/mL, the sensitivity was 73.91%, 71.43%, and 77.78% and area under the curve was 0.756, 0.753, and 0.761 for meningioma group, grade I, and grade II subgroups, respectively, and specificity was 69.23% for each group.

CONCLUSIONS

MIR17HG protein expression was found to have a higher level in meningiomas than in normal meninges tissues in our study. Considering the recurrence and irresectability for some meningiomas, which require further treatment, MIR17HG may be a new target for treatment in meningiomas and our study will shed light on further studies.

The Loss of 1p as a Reliable Marker of Progression in a Child with Aggressive Meningioma: A 16-Year Follow-Up Case Report

BACKGROUND

Here, we present the case of a 32-year-old female with a progressing history of meningioma for 16 years starting with an ethmoidal lesion in 2002. The initial tumor specimen of this patient showed a deletion of the short arm of chromosome 1 through a translocation between chromosomes 1 and 11 (t[1; 11]) as well as additional chromosomal aberrations, including partial or complete monosomy of chromosomes 2, 6, 7, 11, 13, and 22. These molecular characteristics were already known to be associated with an aggressive course of the disease, and the patient was, therefore, included in a strict follow-up regime. From 2003 to 2019, the patient suffered multiple relapses and consecutive tumor resections.

METHODS

Tumor specimen from 2017 was examined using a genome-wide methylation analysis as well as a whole-genome sequencing.

RESULTS

These analyses confirmed the findings of 2002 and proved genetic alteration in the meningioma to be very stable over the time. Yet SMO and AKT1 mutations, which have been described to be paradigmatic in frontobasal meningioma, could not be found.

CONCLUSIONS

Genetic characteristics seem to be very stable during progression of the disease. The loss of 1p represents to be a potential marker for the poor clinical course of our child meningioma. In 2019, our patient passed away due to the progress of her meningioma disease.

Nonneuroendocrine Neoplasms of the Pituitary Region

CONTEXT

Although most sellar lesions are related to pituitary adenomas, the region gives rise to a variety of neoplasms that can be associated with substantial morbidity and/or mortality.

DESIGN

Information from reviews and guidelines of relevant societies dealing with such neoplasms, as well as articles that have provided new developments that made important contributions to their pathogenesis and treatment up to 2018, were obtained: public indexes such as PubMed/MEDLINE were used with the relevant search items.

RESULTS

Sellar neoplasms have a worse outcome than pituitary adenomas that is related not only to their natural history but also to side effects of therapies and evolving endocrine and/or hypothalamic deficiencies. Recent imaging advances have established the radiological fingerprint of some of these neoplasms, and several chromosomal aberrations have also been identified. Although established approaches along with new surgical and radiotherapeutic approaches remain the main treatment modalities, recent evidence has provided insight into their molecular pathogenesis involving, other than chemotherapy, treatments with targeted agents as in gliomas and craniopharyngiomas bearing BRAF mutations. Development of predictive markers of recurrences may also identify high-risk patients, including proliferative markers and expression of the progesterone receptor in meningiomas, and lead to less aggressive surgery. Owing to the rarity and complexity of these neoplasms, patients should be managed in dedicated centers.

CONCLUSIONS

The diagnosis and management of sellar neoplasms necessitate a multidisciplinary approach. Following evolving recent advances in their diagnosis and therapy, such a multidisciplinary approach needs to be extended to establish evidence-based diagnostic and management plans.

Deletions in the 17q chromosomal region and their influence on the clonal cytogenetic evolution of recurrent meningiomas

Objective

Meningiomas are among the most frequent intracranial tumors. Although the majority of meningiomas can be cured by surgical resection, up to 20% of the patients develop an aggressive clinical course with tumor recurrence or progressive disease.

Cytogenetically, meningiomas frequently harbour a normal karyotype or monosomy of chromosome 22 as the sole anomaly. However, progression of meningiomas is associated with a non-random pattern of secondary losses of the chromosomes and chromosomal regions 1p, 6, 10, 14, 18, and 19. There is evidence, that loss of chromosome 17 might be involved in the clonal cytogenetic evolution of recurrent meningiomas. The aim of this study was to determine the role of deletions in the 17q chromosomal region in patients with recurrent meningiomas.

Results

The authors retrospectively reviewed all patients that underwent repeated surgery for recurrent meningiomas between 1999 and 2015 at the Department of Neurosurgery of the Saarland University Hospital. Patients were included in this study if tumor samples from two or more different meningiomas were available.

A total of 7 patients underwent repeated surgery for recurrent meningiomas (4 males, 3 females, mean age: 45.4 years at the date of surgery) between 1999 and 2015. Collectively, 22 biopsies were analyzed with FISH (fluorescence-in-situ-hybridization) for the chromosomal region 17q23.3. In 20/22 (90.1%) specimens, the tumor samples harboured a significant deletion in the chromosomal region 17q (range: 10 to 63% of the cells). In 3/3 (100%) cases, deletion in the 17q chromosomal region was detectable in the primary tumor. In the tumor evolution, there was no steady in- or decrease in the percentage of this deletion.

Conclusion

Deletion in the 17q chromosomal region was present in the patients’ primary tumors as well as in late recurrences. Overall, a significant deletion in the 17q chromosomal region was detected in 90.1% of the tumors. Thus, the authors assume that deletion in the 17q chromosomal region displays rather an early event in meningioma progression. Accordingly, deletion in the 17q chromosomal region might clinically serve as a potential early marker for malignancy and a higher risk for recurrence in meningiomas.

Genomic analysis of synchronous intracranial meningiomas with different histological grades

Although meningioma is the most common primary tumor of the central nervous system, the mechanism of progression from benign to atypical or anaplastic grade remains elusive. The present case reports the genomic evaluation of two synchronous meningiomas with different histological grades (benign and atypical) in the same patient. Under the assumption that the atypical tumor may have progressed from the benign tumor, the clonal origin of the lesions was investigated to identify genomic events responsible for the oncogenic process of evolution to higher grades in meningioma. A 59 year-old female patient was diagnosed with two synchronous meningiomas with different histological grades, benign and atypical. Whole-exome sequencing (WES) and RNA sequencing (RNA-seq) analysis of both tumors were done. WES analysis showed that each meningioma harbored distinct mutation profiles, and RNA-seq analysis revealed distinct gene expression profiles between the two tumors. The only apparent common genetic abnormality found in both tumors was the loss of heterozygosity of chromosome 22, raising the possibility that this event is the initial step in tumor formation, after which distinct subsequent mutations lead to the evolvement of two separate tumors of different grades. The result provides additional evidence on previous reports suggesting separate, independent mechanism of progression into higher grades in meningioma.

Advances in meningioma genetics: novel therapeutic opportunities

Meningiomas currently are among the most frequent intracranial tumours. Although the majority of meningiomas can be cured by surgical resection, ∼20% of patients have an aggressive clinical course with tumour recurrence or progressive disease, resulting in substantial morbidity and increased mortality of affected patients. During the past 3 years, exciting new data have been published that provide insights into the molecular background of meningiomas and link sites of tumour development with characteristic histopathological and molecular features, opening a new road to novel and promising treatment options for aggressive meningiomas. A growing number of the newly discovered recurrent mutations have been linked to a particular clinicopathological phenotype. Moreover, the updated WHO classification of brain tumours published in 2016 has incorporated some of these molecular findings, setting the stage for the improvement of future therapeutic efforts through the integration of essential molecular findings. Finally, an additional potential classification of meningiomas based on methylation profiling has been launched, which provides clues in the assessment of individual risk of meningioma recurrence. All of these developments are creating new prospects for effective molecularly driven diagnosis and therapy of meningiomas.

Global epigenetic profiling identifies methylation subgroups associated with recurrence-free survival in meningioma

Meningioma is the most common primary brain tumor and carries a substantial risk of local recurrence. Methylation profiles of meningioma and their clinical implications are not well understood. We hypothesized that aggressive meningiomas have unique DNA methylation patterns that could be used to better stratify patient management. Samples (n = 140) were profiled using the Illumina HumanMethylation450BeadChip. Unsupervised modeling on a training set (n = 89) identified 2 molecular methylation subgroups of meningioma (MM) with significantly different recurrence-free survival (RFS) times between the groups: a prognostically unfavorable subgroup (MM-UNFAV) and a prognostically favorable subgroup (MM-FAV). This finding was validated in the remaining 51 samples and led to a baseline meningioma methylation classifier (bMMC) defined by 283 CpG loci (283-bMMC). To further optimize a recurrence predictor, probes subsumed within the baseline classifier were subject to additional modeling using a similar training/validation approach, leading to a 64-CpG loci meningioma methylation predictor (64-MMP). After adjustment for relevant clinical variables [WHO grade, mitotic index, Simpson grade, sex, location, and copy number aberrations (CNAs)] multivariable analyses for RFS showed that the baseline methylation classifier was not significant (p = 0.0793). The methylation predictor, however, was significantly associated with tumor recurrence (p < 0.0001). CNAs were extracted from the 450k intensity profiles. Tumor samples in the MM-UNFAV subgroup showed an overall higher proportion of CNAs compared to the MM-FAV subgroup tumors and the CNAs were complex in nature. CNAs in the MM-UNFAV subgroup included recurrent losses of 1p, 6q, 14q and 18q, and gain of 1q, all of which were previously identified as indicators of poor outcome. In conclusion, our analyses demonstrate robust DNA methylation signatures in meningioma that correlate with CNAs and stratify patients by recurrence risk.

ARID4B is a good biomarker to predict tumour behaviour and decide WHO grades in gliomas and meningiomas

Aims

Although ARID4B is known to promote tumour metastasis in breast cancer and inhibit transformation and progression in leukaemia, the possible effect of ARID4B on primary brain tumours (PBTs) is not well characterised. We tested the hypothesis that expression of ARID4B correlates with WHO grade and survival in patients with PBTs.

Methods

Western blot analysis was performed on protein lysates prepared from normal brain tissue and glioma cell lines (U87MG, LN229, GBM8401 and U118MG). Subsequently, immunohistochemical analysis of ARID4B was performed on 2 tissue microarrays, including 12 normal brain tissues, 63 meningiomas with different subtypes, 232 gliomas of various grades and degrees of differentiation, 8 central neurocytomas and 4 chordomas. The ARID4B immunostaining score was calculated by multiplying the intensity score by the percentage of tumour cells expressing ARID4B.

Results

In vitro, ARID4B protein expression was increased in some glioma cell lines. In addition, the average ARID4B immunostaining score was 38.03, 79.09, 129.76 and 119.32, respectively, in gliomas of WHO grade I, II, III and IV. Higher ARID4B immunostaining score was significantly correlated with more advanced WHO grade of gliomas (p=7.4×10–6) and meningiomas. Finally, higher ARID4B expression tended to the shorter survival rates, but did not reach statistical significance.

Conclusions

ARID4B overexpression presented in most of PBTs, rather than non-neoplastic brain tissue, and correlated with WHO grades in meningiomas and gliomas. Therefore, ARID4B is a satisfactory biomarker to highlight tumour component and predict tumour behaviour in primary brain neoplasms.

Genetic/molecular alterations of meningiomas and the signaling pathways targeted

Meningiomas are usually considered to be benign central nervous system tumors; however, they show heterogenous clinical, histolopathological and cytogenetic features associated with a variable outcome. In recent years important advances have been achieved in the identification of the genetic/molecular alterations of meningiomas and the signaling pathways involved. Thus, monosomy 22, which is often associated with mutations of the NF2 gene, has emerged as the most frequent alteration of meningiomas; in addition, several other genes (e.g., AKT1, KLF4, TRAF7, SMO) and chromosomes have been found to be recurrently altered often in association with more complex karyotypes and involvement of multiple signaling pathways. Here we review the current knowledge about the most relevant genes involved and the signaling pathways targeted by such alterations. In addition, we summarize those proposals that have been made so far for classification and prognostic stratification of meningiomas based on their genetic/genomic features.

SEL1L SNP rs12435998, a predictor of glioblastoma survival and response to radio-chemotherapy

The suppressor of Lin-12-like (C. elegans) (SEL1L) is involved in the endoplasmic reticulum (ER)-associated degradation pathway, malignant transformation and stem cells.

In 412 formalin-fixed and paraffin-embedded brain tumors and 39 Glioblastoma multiforme (GBM) cell lines, we determined the frequency of five SEL1L single nucleotide genetic variants with regulatory and coding functions by a SNaPShot™ assay. We tested their possible association with brain tumor risk, prognosis and therapy.

We studied the in vitro cytotoxicity of valproic acid (VPA), temozolomide (TMZ), doxorubicin (DOX) and paclitaxel (PTX), alone or in combination, on 11 GBM cell lines, with respect to the SNP rs12435998 genotype.

The SNP rs12435998 was prevalent in anaplastic and malignant gliomas, and in meningiomas of all histologic grades, but unrelated to brain tumor risks. In GBM patients, the SNP rs12435998 was associated with prolonged overall survival (OS) and better response to TMZ-based radio-chemotherapy. GBM stem cells with this SNP showed lower levels of SEL1L expression and enhanced sensitivity to VPA.

Malignant progression to anaplastic meningioma: Neuropathology, molecular pathology, and experimental models

Meningioma is a common adult intracranial tumor, and while several cases are considered benign, a subset is malignant with biologically aggressive behavior and is refractory to current treatment strategies of combined surgery and radiotherapy. Anaplastic meningiomas are quite aggressive and correspond to a World Health Organization (WHO) Grade III tumor. This highly aggressive phenotype mandates the need for more efficacious therapies. Designing rational therapies for treatment will have its foundation in the biologic understanding of involved genes and molecular pathways in these types of tumors. Anaplastic meningiomas (WHO Grade III) can arise from malignant transformation of lower grade (WHO Grade I/II) tumors, however there is an incomplete understanding of specific genetic drivers of malignant transformation in these tumors. Here, the current understanding of anaplastic meningiomas is reviewed in the context of human neuropathologic specimens and small animal models.

Development of patient-derived xenograft models from a spontaneously immortal low-grade meningioma cell line, KCI-MENG1

Background

There is a paucity of effective therapies for recurrent/aggressive meningiomas. Establishment of improved in vitro and in vivo meningioma models will facilitate development and testing of novel therapeutic approaches.

Methods

A primary meningioma cell line was generated from a patient with an olfactory groove meningioma. The cell line was extensively characterized by performing analysis of growth kinetics, immunocytochemistry, telomerase activity, karyotype, and comparative genomic hybridization. Xenograft models using immunocompromised SCID mice were also developed.

Results

Histopathology of the patient tumor was consistent with a WHO grade I typical meningioma composed of meningothelial cells, whorls, and occasional psammoma bodies. The original tumor and the early passage primary cells shared the standard immunohistochemical profile consistent with low-grade, good prognosis meningioma. Low passage KCI-MENG1 cells were composed of two cell types with spindle and round morphologies, showed linear growth curve, had very low telomerase activity, and were composed of two distinct unrelated clones on cytogenetic analysis. In contrast, high passage cells were homogeneously round, rapidly growing, had high telomerase activity, and were composed of a single clone with a near triploid karyotype containing 64–66 chromosomes with numerous aberrations. Following subcutaneous and orthotopic transplantation of low passage cells into SCID mice, firm tumors positive for vimentin and progesterone receptor (PR) formed, while subcutaneous implant of high passage cells yielded vimentin-positive, PR-negative tumors, concordant with a high-grade meningioma.

Conclusions

Although derived from a benign meningioma specimen, the newly-established spontaneously immortal KCI-MENG1 meningioma cell line can be utilized to generate xenograft tumor models with either low- or high-grade features, dependent on the cell passage number (likely due to the relative abundance of the round, near-triploid cells). These human meningioma mouse xenograft models will provide biologically relevant platforms from which to investigate differences in low- vs. high-grade meningioma tumor biology and disease progression as well as to develop novel therapies to improve treatment options for poor prognosis or recurrent meningiomas.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0596-8) contains supplementary material, which is available to authorized users.

Pathology and molecular genetics of meningioma: recent advances

Meningiomas are the most common intracranial primary neoplasm in adults. Although the spectrum of clinical and molecular genetic issues regarding meningiomas remains undefined, novel genetic alterations that are associated with tumor morphology, malignancy, or location have recently been discovered. This review focuses on recent advances in understanding of the heterogenous pathology of meningiomas, particularly on associations between the clinical, histological, etiological, epidemiological, and molecular genetical aspects of the neoplasm.

Presence of matrix metalloproteinase-2 and tissue inhibitor matrix metalloproteinase-2 gene polymorphisms and immunohistochemical expressions in intracranial meningiomas

OBJECT

Meningiomas are benign extraaxial tumors with a slow progression. Some of them, in spite of being benign in nature, may show an aggressive progression pattern. To investigate the behavioral characteristics of meningiomas, researchers have studied matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), interstitial collagens, proteins, vascular endothelial growth factors (VEGF), and tumor necrosis factors.

METHODS

In this study, the authors investigated MMP2 and TIMP2 gene polymorphisms in formalin-fixed paraffin-embedded tissue samples obtained from meningioma patients who had previously undergone surgery at the authors' institution. In addition, brain invasion, Ki-67 index, and MMP-2 and TIMP-2 expressions were investigated using immunohistochemical methods. MMP2 (735C>T, 1575G>A, 1306C>T) and TIMP2 (418G>C, 303C>T) gene polymorphisms were investigated from paraffin-embedded tissue sections using the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

There were statistically significant differences between genotype (p = 0.001) and allele frequencies (p = 0.001 and OR 7.4 [95% CI 1.5-36.2]) in patient and control groups for MMP2 1306C>T polymorphism. The authors did not find a statistically significant difference for other polymorphisms. GA genotype was found to be more frequent when brain invasion was suspected for MMP2 1575G>A polymorphism (p = 0.006). There was not a statistically significant difference for other MMP2 or TIMP2 gene polymorphisms.

CONCLUSIONS

The authors' results support the importance of MMPs and their tissue inhibitors in meningioma pathogenesis. In future studies, these gene polymorphisms, especially MMP2 1306C>T and 1575G>A, should be investigated for meningioma or brain invasion susceptibility in larger study groups.

Molecular biological determinations of meningioma progression and recurrence

Meningiomas are tumors that arise from the coverings of the brain or spinal cord. 5% of the cases turn into malignant forms with aggressive clinical behavior and increased risk of tumor recurrence. One hundred and five patients with meningiomas were operated by open surgery. To investigate predictors of meningioma recurrence in total 124 samples of 105 patients were investigated by iFISH. Dual-probe hybridization was performed to access chromosomal alterations of chromosomes 1p-, 9p- and 22q. Additionally, methylation of TIMP3 and p16 was analyzed with MS-PCR. Of the 105 investigated tumors 59.1% (62/105) were WHO grade I, 33.3% (35/105) were WHO grade II and 7.7% (8/105) were anaplastic meningiomas (grade III), respectively. The histopathological data correlates with the recurrence rate of the investigated meningiomas. Hypermethylation of TIMP3 was detected in 13.3% of all meningiomas: 10.9% in WHO grade I meningiomas, 25.0% in grade II and 14.3% in grade III meningiomas, respectively. No correlation of TIMP3 hypermethylation with tumor recurrence or WHO grade (p = 0.2) was observed. Interestingly, deletion of 1p36 emerged as a significant predictor of shorter overall survival (log rank test, p<0.001), whereas TIMP3 promoter methylation had no significant effect on overall survival (log rank test, p = 0.799). The results of the current study support the finding that the deletion of chromosome 1p is an independent marker of meningioma recurrence and progression (p = 0.0097). Therefore the measurement of genetic aberrations in meningiomas allows in a combined histological approach a more precise assessment of the prognosis of meningiomas than histopathology alone.

Proposal for a new risk stratification classification for meningioma based on patient age, WHO tumor grade, size, localization, and karyotype

BACKGROUND

Tumor recurrence remains the major clinical complication of meningiomas, the majority of recurrences occurring among WHO grade I/benign tumors. In the present study, we propose a new scoring system for the prognostic stratification of meningioma patients based on analysis of a large series of meningiomas followed for a median of >5 years.

METHODS

Tumor cytogenetics were systematically investigated by interphase fluorescence in situ hybridization in 302 meningioma samples, and the proposed classification was further validated in an independent series of cases (n = 132) analyzed by high-density (500K) single-nucleotide polymorphism (SNP) arrays.

RESULTS

Overall, we found an adverse impact on patient relapse-free survival (RFS) for males, presence of brain edema, younger patients (<55 years), tumor size >50 mm, tumor localization at intraventricular and anterior cranial base areas, WHO grade II/III meningiomas, and complex karyotypes; the latter 5 variables showed an independent predictive value in multivariate analysis. Based on these parameters, a prognostic score was established for each individual case, and patients were stratified into 4 risk categories with significantly different (P < .001) outcomes. These included a good prognosis group, consisting of approximately 20% of cases, that showed a RFS of 100% ± 0% at 10 years and a very poor-prognosis group with a RFS rate of 0% ± 0% at 10 years. The prognostic impact of the scoring system proposed here was also retained when WHO grade I cases were considered separately (P < .001).

CONCLUSIONS

Based on this risk-stratification classification, different strategies may be adopted for follow-up, and eventually also for treatment, of meningioma patients at different risks for relapse.

Establishment of a molecular cytogenetic analysis for native tumor tissue of meningiomas-suitable for clinical application

Background

Meningiomas are mostly benign tumors which arise from the meninges. They are among the cytogenetically best-studied solid tumors, mostly displaying a normal karyotype or, as a typical primary aberration, monosomy of chromosome 22. Further secondary chromosomal aberrations, especially the deletion of chromosome 1p, are correlated with increasing biological aggressiveness up to malignancy. These data are derived from the cytogenetical characterization of 661 meningiomas, from which the genetic progression score (GPS) has been developed. Due to the high expenditure of time and the expert knowledge for the cytogenetical characterization, the aim of this work was to establish an equally reliable yet more rapid clinical diagnosis based on fluorescence in situ hybridization (FISH) on meningiomas. Thus a comparison between the native tumor tissue and the primary culture of the same tumor was done in order to determine the most efficient method for a molecular cytogenetic characterization. The diagnostic procedure has to deliver fast and robust results, since they must enable the attending physician to plan the appropriate follow-up regimens for the patients. All in all, preparations of native tumor tissue as well as preparations of cell culture of 22 meningiomas were tested with FISH for aberrations concerning the prognostically relevant chromosome regions 1p and 9p, and the chromosomes 10, 14, 18 and 22 in comparison with the particular karyotypes revealed by conventional karyotyping using G-banding.

Results

The FISH examinations between native and cultured cells showed an accordance of 93.4%. The comparison of FISH data and karyotyping presented accordance to the greatest possible extent concerning the chromosomes 14, 18 and 22, but to detect the progression associated losses of 1p and 9p FISH is the most sensitive method.

Conclusions

The raised data reveal that both methods can be used for a significant analysis of chromosome aberrations on meningiomas. As a result of that the complex primary culture could also be avoided. Therefore a clinical diagnosis based on FISH on meningiomas is at hand for the assignment of patients to a suitable follow-up regimen.

Novel therapies for meningiomas

Although advances in surgery, radiation therapy and stereotactic radiosurgery have significantly improved the treatment of meningiomas, there remains an important subset of patients who remain refractory to conventional therapy. Treatment with chemotherapeutic agents such as hydroxyurea and alpha-interferon has provided minimal benefit. In this review, the role of newly emerging novel therapies for meningiomas, with a focus on targeted molecular agents, will be discussed.

Association study on MTHFR polymorphisms and meningioma in northern China

BACKGROUND

Meningioma is the second most common primary tumor of the central nervous system, and multiple genetic and environmental factors contribute to its etiology. Methylene tetrahydrofolate reductase (MTHFR) is a pivotal enzyme in folate metabolism. We conducted a case-control study to investigate the association of the MTHFR gene and meningioma in a Han population in northern China.

METHODS

We genotyped two SNPs (C677T and A1298C) using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). In this study 317 meningioma patients were compared to 320 normal controls. Data were analyzed by SPSS 13.0 and HaploView software.

RESULTS

We found a significant difference in the frequency distribution of 677CC and 677TT between cases and control groups; another SNP exhibited no differences in any genotype between the two cohorts.

CONCLUSION

The results revealed that variations of the MTHFR gene were associated with meningioma; this finding indicates that the MTHFR gene potentially plays an important role in the pathogenesis of meningioma in the Northern Chinese Han population.

Atypical meningioma in the posterior fossa associated with colpocephaly and agenesis of the corpus callosum

Colpocephaly is an abnormal enlargement of the occipital horns, i.e., the posterior or rear portions of the lateral ventricles of the brain, and is associated with several other brain abnormalities. Colpocephaly is occasionally misdiagnosed as hydrocephalus, and various etiologies have been postulated, including genetic disorders and errors of morphogenesis. Meanwhile, chromosomal losses including 22q and rarely 21q are observed in malignant and atypical meningiomas. We report an uncommon case of a 67-year-old woman with colpocephaly and an atypical meningioma in the posterior fossa. There were no neurological deficits or family history of hereditary neuropsychiatric disorders. Brain magnetic resonance (MR) images showed bilateral enlarged occipital horns, agenesis of corpus callosum, and a cerebellar mass in the right cerebellar hemisphere. Right suboccipital craniotomy was performed, and the tumor was resected totally. Pathological study of the surgical specimen showed findings of atypical meningioma, and the postoperative course was uneventful until hydrocephalus developed. At 36th day after tumor removal, the patient undertook an external ventricular drainage followed by replacement of the ventriculoperitoneal shunt. We discuss the importance of colpocephaly in terms of the differential diagnosis for hydrocephalus and review the pertinent literature.

Evolution and future of skull base surgery: the paradigm of skull base meningiomas

BACKGROUND

Skull base meningiomas represent the paradigm for the evolution of skull base surgery within the past 50 years into a distinct neurosurgical subspecialty.

METHODS

From 2005 to 2011, 117 patients with cranial base meningiomas underwent surgical resection. Extent of resection, histologic grade, complications, functional status, and recurrence-free and overall survival data are presented.

RESULTS

The summary rate of gross total resection was 53.0%. The surgical complication and mortality rates were 17.9% and 0.9%, respectively. Five-year recurrence-free survival was 88.0% for grade I meningiomas. A total of 90.3% of patients had a Karnofsky performance score ≥ 80 at last follow-up.

CONCLUSIONS

A large contemporary series of skull base meningiomas is presented. In addition, the evolution of surgical approaches to skull base meningiomas is reviewed, together with the current issues regarding radiation therapy, management of cavernous sinus tumor, oncologic management of atypical and malignant subtypes, molecular genetics, and future therapeutic options.