Meningiomas and neurofibromatosis

K, Baral A. Bilateral vestibular schwannoma with a cooccurring meningioma in a child: a case report and review of literature

Introduction

Meningioma and vestibular schwannoma (VS) are the first and second most common benign central nervous system tumors. The coexistence of VS and meningioma presents a rare clinical scenario, particularly in pediatric patients. This report presents a case of bilateral VS with a cooccurring meningioma in a Nepali child and provides an overview of the literature on this condition.

Case report

A 15-year-old male presented with bilateral sensorineural hearing loss, seizures, and neurological deficits and was ultimately diagnosed with concomitant bilateral acoustic neuroma and meningioma. The patient underwent radiosurgery for bilateral VS and nonoperative management of the meningioma. Long-term follow-up revealed symptomatic improvement, emphasizing the importance of a multidisciplinary approach in managing such complex cases. The management of these tumors requires tailored treatment strategies guided by tumor characteristics and associated risks.

Discussion

Meningioma and VS are common tumors of the central nervous system. Their coexistence is possible in neurofibromatosis type 2 but is exceedingly rare in pediatric age group. The tumors, often coexisting, pose diagnostic challenges. Diagnosis relies on clinical and genetic features, with multidisciplinary management involving various specialists. Treatment aims to preserve function and quality of life, utilizing approaches such as bevacizumab and surgical intervention. The role of radiation therapy remains uncertain. Genetic testing and regular monitoring are vital for early detection and intervention.

Conclusion

The cooccurrence of acoustic neuromas and meningiomas is poorly understood, with limited reported cases and unclear pathophysiological mechanisms. Further research into the genetic and molecular mechanisms underlying the coexistence of these tumors is needed to optimize patient outcomes in this rare clinical entity.

Meningioma recurrence: Time for an online prediction tool?

Background

Meningioma, the most common brain tumor, traditionally considered benign, has a relatively high risk of recurrence over a patient's lifespan. In addition, with the emergence of several clinical, radiological, and molecular variables, it is becoming evident that existing grading criteria, including Simpson's and World Health Organization classification, may not be sufficient or accurate. As web-based tools for widespread accessibility and usage become commonplace, such as those for gene identification or other cancers, it is timely for meningioma care to take advantage of evolving new markers to help advance patient care.

Methods

A scoping review of the meningioma literature was undertaken using the MEDLINE and Embase databases. We reviewed original studies and review articles from September 2022 to December 2023 that provided the most updated information on the demographic, clinical, radiographic, histopathological, molecular genetics, and management of meningiomas in the adult population.

Results

Our scoping review reveals a large body of meningioma literature that has evaluated the determinants for recurrence and aggressive tumor biology, including older age, female sex, genetic abnormalities such as telomerase reverse transcriptase promoter mutation, CDKN2A deletion, subtotal resection, and higher grade. Despite a large body of evidence on meningiomas, however, we noted a lack of tools to aid the clinician in decision-making. We identified the need for an online, self-updating, and machine-learning-based dynamic model that can incorporate demographic, clinical, radiographic, histopathological, and genetic variables to predict the recurrence risk of meningiomas.

Conclusion

Although a challenging endeavor, a recurrence prediction tool for meningioma would provide critical information for the meningioma patient and the clinician making decisions on long-term surveillance and management of meningiomas.

The Natural History and Treatment of Meningiomas: An Update

Meningiomas are the most frequent nonmalignant tumors of the central nervous system (CNS). Despite their benign nature and slow-growing pattern, if not diagnosed early, these tumors may reach relatively large sizes causing significant morbidity and mortality. Some variants are located in hard-to-access locations, compressing critical neurovascular structures, and making the surgical management even more challenging. Although most meningiomas have a good long-term prognosis after treatment, there are still controversies over their management in a subset of cases. While surgery is the first-line treatment, the use of fractionated radiotherapy or stereotactic radiosurgery is indicated for residual or recurrent tumors, small lesions, and tumors in challenging locations. Advances in molecular genetics and ongoing clinical trial results have recently helped both to refine the diagnosis and provide hope for effective biomolecular target-based medications for treatment. This article reviews the natural history and current therapeutic options for CNS meningiomas.

Early Preventive Strategies and CNS Meningioma - Is This Feasible? A Comprehensive Review of the Literature

BACKGROUND

Meningiomas are one of the most common benign primary brain tumors; however, there is a paucity of literature on potential preventability. This comprehensive review aimed to explore the existing evidence for the potential risk factors that may contribute to meningioma development and to discuss early prevention strategies.

METHODS

Literature search was conducted via MEDLINE, Embase, Web of Science, and Cochrane Database to retrieve existing literature on various environmental exposures and lifestyle behaviors that are potential risk factors for the development of meningiomas.

RESULTS

Significant risk factors included exposure to ionizing radiation and certain environmental chemicals. Notably, this study also identified that cigarette smoking and obesity are associated with the development of meningiomas. To date, wireless phone usage, hormonal exposures, dietary factors, and traumatic brain injury remain inconclusive. Early prevention strategies should primarily be family-driven, community-based, and public health-endorsed strategies. Targeting unhealthy behaviors through healthcare organizations could execute a pivotal role in the maintenance of an optimum lifestyle, reducing the development of risk factors pertinent to meningiomas.

CONCLUSIONS

To our knowledge, this is the first study that offers a perspective on prevention of meningiomas. A causal relationship of risk factors in developing meningiomas cannot be directly established with the current evidence. We are aware of the limitations of the hypothesis, but we believe that this study will raise more awareness and our findings could potentially be endorsed by organizations promoting health across the globe. Further prospective and retrospective studies will shed more light on this topic and help establish a definitive relationship.

Meningioma animal models: a systematic review and meta-analysis

BACKGROUND

Animal models are widely used to study pathological processes and drug (side) effects in a controlled environment. There is a wide variety of methods available for establishing animal models depending on the research question. Commonly used methods in tumor research include xenografting cells (established/commercially available or primary patient-derived) or whole tumor pieces either orthotopically or heterotopically and the more recent genetically engineered models-each type with their own advantages and disadvantages. The current systematic review aimed to investigate the meningioma model types used, perform a meta-analysis on tumor take rate (TTR), and perform critical appraisal of the included studies. The study also aimed to assess reproducibility, reliability, means of validation and verification of models, alongside pros and cons and uses of the model types.

METHODS

We searched Medline, Embase, and Web of Science for all in vivo meningioma models. The primary outcome was tumor take rate. Meta-analysis was performed on tumor take rate followed by subgroup analyses on the number of cells and duration of incubation. The validity of the tumor models was assessed qualitatively. We performed critical appraisal of the methodological quality and quality of reporting for all included studies.

RESULTS

We included 114 unique records (78 using established cell line models (ECLM), 21 using primary patient-derived tumor models (PTM), 10 using genetically engineered models (GEM), and 11 using uncategorized models). TTRs for ECLM were 94% (95% CI 92-96) for orthotopic and 95% (93-96) for heterotopic. PTM showed lower TTRs [orthotopic 53% (33-72) and heterotopic 82% (73-89)] and finally GEM revealed a TTR of 34% (26-43).

CONCLUSION

This systematic review shows high consistent TTRs in established cell line models and varying TTRs in primary patient-derived models and genetically engineered models. However, we identified several issues regarding the quality of reporting and the methodological approach that reduce the validity, transparency, and reproducibility of studies and suggest a high risk of publication bias. Finally, each tumor model type has specific roles in research based on their advantages (and disadvantages).

SYSTEMATIC REVIEW REGISTRATION

PROSPERO-ID CRD42022308833.

Meningiomas in patients with neurofibromatosis type 2 predominantly comprise 'immunogenic subtype' tumours characterised by macrophage infiltration

Although recent molecular analyses revealed that sporadic meningiomas have various genetic, epigenetic, and transcriptomic profiles, meningioma in patients with neurofibromatosis type 2 (NF2) have not been fully elucidated. This study investigated meningiomas' clinical, histological, and molecular characteristics in NF2 patients. A long-term retrospective follow-up (13.5 ± 5.5 years) study involving total 159 meningiomas in 37 patients with NF2 was performed. Their characteristics were assessed using immunohistochemistry (IHC), bulk-RNA sequencing, and copy number analysis. All variables of meningiomas in patients with NF2 were compared with those in 189 sporadic NF2-altered meningiomas in 189 patients. Most meningiomas in NF2 patients were stable, and the mean annual growth rate was 1.0 ± 1.8 cm3/year. Twenty-eight meningiomas (17.6%) in 25 patients (43.1%) were resected during the follow-up period. WHO grade I meningiomas in patients with NF2 were more frequent than in sporadic NF2-altered meningiomas (92.9% vs. 80.9%). Transcriptomic analysis for patients with NF2/sporadic NF2-altered WHO grade I meningiomas (n = 14 vs. 15, respectively) showed that tumours in NF2 patients still had a higher immune response and immune cell infiltration than sporadic NF2-altered meningiomas. Furthermore, RNA-seq/IHC-derived immunophenotyping corroborated this enhanced immune response by identifying myeloid cell infiltration, particularly in macrophages. Clinical, histological, and transcriptomic analyses of meningiomas in patients with NF2 demonstrated that meningiomas in NF2 patients showed less aggressive behaviour than sporadic NF2-altered meningiomas and elicited a marked immune response by identifying myeloid cell infiltration, particularly of macrophages.

Surveillance, Epidemiology, and End Results database and propensity score matching analysis of postoperative radiotherapy for non-malignant meningioma: A retrospective cohort study

BACKGROUND

The clinical effect of postoperative radiotherapy (PORT) in non-malignant meningioma (NMM) has not been well explored.

METHODS

A total of 8629 patients with NMM (surgery alone group: n = 7716, postoperative radiotherapy group: n = 913) were obtained from the Surveillance, Epidemiology, and End Results database. Patient profiles were matched by 1:1 propensity score matching (PSM). Logistic regression analysis was performed to identify factors associated with PORT versus surgery alone (SA). Univariate and multivariate Cox regression analyses determined prognostic variables with overall survival (OS) in NMM. Subgroup analyses were performed with Cox proportional hazards regression models.

RESULTS

All the SA (n = 7716) and PORT (n = 913) groups were included. Women with PORT (66.3%) and SA (70.9%) were almost twice as likely as men, and tumors with benign behaviors in the SA group were almost seven times more frequent than those with malignant characteristics. We explored the demographic, clinical characteristics, and prognostic factors in NMM. Laterality, surgery, tumor size, diagnosis year, age, and tumor behavior were associated with PORT versus SA. Patients treated with PORT had better OS than those treated with SA (p = 0.03). After PSM, PORT remained comparable to SA (hazard ratio 0.56, 95% confidence interval 0.35-0.88, p = 0.013). In the subgroup analysis of PORT treatment, borderline malignant behavior increased the death risk by 23%, while other variables did not have a significant clinical benefit (p > 0.05).

CONCLUSIONS

Borderline malignant behavior should be considered seriously, and the PORT regimen should be actively implemented for patients with benign meningiomas.

Long Term Outcome and Quality of Life of Intracranial Meningioma Patients Treated with Pencil Beam Scanning Proton Therapy

The aim of this study was to assess the clinical outcome, including QoL, of patients with intracranial meningiomas WHO grade 1-3 who were treated with Pencil Beam Scanning Proton Therapy (PBS PT) between 1997 and 2022. Two hundred patients (median age 50.4 years, 70% WHO grade 1) were analyzed. Acute and late side effects were classified according to CTCAE version 5.0. Time to event data were calculated. QoL was assessed descriptively by the EORTC-QLQ-C30 and BN20 questionnaires. With a median follow-up of 65 months (range: 3.8-260.8 months) the 5 year OS was 95.7% and 81.8% for WHO grade 1 and grade 2/3, respectively (p < 0.001). Twenty (10%) local failures were observed. Failures occurred significantly (p < 0.001) more frequent in WHO grade 2 or 3 meningioma (WHO grade 1: n = 7, WHO grade 2/3: n = 13), in patients with multiple meningiomas (p = 0.005), in male patients (p = 0.005), and when PT was initiated not as upfront therapy (p = 0.011). There were no high-grade toxicities in the majority (n = 176; 88%) of patients. QoL was assessed for 83 (41.5%) patients and for those patients PT did not impacted QoL negatively during the follow-up. In summary, we observed very few local recurrences of meningiomas after PBS PT, a stable QoL, and a low rate of high-grade toxicity.

Angiomatous meningioma with bizarre nuclei: A case report

Angiomatous meningioma (AM) is a relatively rare subtype of WHO grade I meningioma. A relatively rare case of AM was recently encountered in a 45-year-old woman. The present case not only observed the typical AM histological pattern but also a large number of cells with bizarre, large, deeply staining and unevenly distributed nuclei. These cells with bizarre nuclei showed a similar pattern of immunoreactivity as meningeal epithelial cells. Although the presence of a large number of cells with bizarre nuclei in this case increased tumour cell atypia, the cells did not differ with regard to proliferative activity and mitotic imaging. Therefore, the patient was ultimately diagnosed as having AM with bizarre nuclei, WHO grade I. This manifestation of nuclear atypia and pleomorphism may be due to 'degenerative changes' in pre-existing, long-established vascular lesions, similar to those seen in degenerative schwannomas and symplastic haemangioma, rather than being considered an indicator of malignancy.

SMARCE1-related meningiomas: A clear example of cancer predisposing syndrome

We report the case of a 16-year-old girl presenting with spinal clear-cell multiple meningiomas (CCMs). In view of this presentation, we sequenced a bioinformatic panel of genes associated with susceptibility to meningioma, identifying a germline heterozygous variant inSMARCE1. Somatic DNA investigations in the CCM demonstrated the deletion of the wild-type allele (loss of heterozygosity, LOH), supporting the causative role of this variant. Family segregation study detected the SMARCE1 variant in the asymptomatic father and in the asymptomatic sister who, nevertheless, presents 2 spinal lesions. Germline heterozygous loss-of-function (LoF) variants in SMARCE1, encoding a protein of the chromatin-remodeling complex SWI/SNF, have been described in few familial cases of susceptibility to meningioma, in particular the CCM subtype. Our case confirms the role of NGS in investigating predisposing genes for meningiomas (multiple or recurrent), with specific regard to SMARCE1 in case of pediatric CCM. In addition to the age of onset, the presence of familial clustering or the coexistence of multiple synchronous meningiomas also supports the role of a genetic predisposition that deserves a molecular assessment. Additionally, given the incomplete penetrance, it is of great importance to follow a specific screening or follow-up program for symptomatic and asymptomatic carriers of pathogenic variants in SMARCE1.

Secondary meningioma after cranial irradiation: case series and comprehensive literature review

BACKGROUND

Secondary meningioma after cranial irradiation, so-called radiation-induced meningioma, is one of the important late effects after cranial radiation therapy. In this report, we analyzed our case series of secondary meningioma after cranial irradiation and conducted a critical review of literature to reveal the characteristics of secondary meningioma.

MATERIALS AND METHODS

We performed a comprehensive literature review by using Pubmed, MEDLINE and Google scholar databases and investigated pathologically confirmed individual cases. In our institute, we found pathologically diagnosed seven cases with secondary meningioma between 2000 and 2018. Totally, 364 cases were analyzed based on gender, WHO grade, radiation dose, chemotherapy. The latency years from irradiation to development of secondary meningioma were analyzed with Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between age at irradiation and the latency years.

RESULTS

The mean age at secondary meningioma development was 35.6 ± 15.7 years and the mean latency periods were 22.6 ± 12.1 years. The latency periods from irradiation to the development of secondary meningioma are significantly shorter in higher WHO grade group (P = 0.0026, generalized Wilcoxon test), higher radiation dose group (P < 0.0001) and concomitant systemic chemotherapy group (P = 0.0003). Age at irradiation was negatively associated with the latency periods (r = -0.23231, P < 0.0001, Spearman's correlation test).

CONCLUSION

Cranial irradiation at older ages, at higher doses and concomitant chemotherapy was associated with a shorter latency period to develop secondary meningiomas. However, even low-dose irradiation can cause secondary meningiomas after a long latency period. Long-term follow-up is necessary to minimize the morbidity and mortality caused by secondary meningioma after cranial irradiation.

[Molecular genetic features of meningiomas]

Meningioma is the most common primary tumor of the central nervous system. Traditional classification is based on histological properties of tumors and distinguishes different grades of meningioma malignancy. However, knowledge about different molecular mechanisms of tumor provided new data on genetic features of meningiomas. The authors analyze current available data on the main driver mutations, new classifications based on molecular genetic characteristics and potential targets for therapy.

Epidemiology and Survival after Spinal Meningioma Surgery: A Nationwide Population-Based Study

STUDY DESIGN

This is a cross-sectional nationwide descriptive observational and analytic retrospective study.

PURPOSE

This study aims to describe and assess survival after spinal meningioma (SM) surgery.

OVERVIEW OF LITERATURE

A few studies report a reduced survival after SM surgery.

METHODS

The current study processed the Système National des Données de Santé (SNDS), the French national administrative medical database, to retrieve appropriate cases.

RESULTS

This study identified 2,844 patients (79.1% females) between 2008 and 2017. The median age at surgery was 66 years (interquartile range [IQR], 56-75 years). Moreover, 95.9% of SMs were removed through posterior or posterolateral approaches, and 6.9% were epidural and 0.7% needed an associated spine stabilization. Benign meningioma represented 92.9%, with 5% and 2.1% atypical and malignant, respectively. The median follow-up was 3.3 years (IQR, 3.1-3.5 years). Of the patients, 0.25% and 1.2% expired within a month and a year of surgery, respectively. At data collection, 225 patients (7.9%) expired. The 5-year overall survival (OS) probability was 90.1% (95% CI, 88.6%-91.7%). However, absolute excess risk of mortality after SM surgery was null, and the related standardized mortality ratio was 1 (95% CI, 0.9-1.2; p =0.565). In the adjusted regression, age at surgery (hazard ratio [HR], 1.06; 95% CI, 1.04-1.07; p <0.001), level of comorbidities (HR, 1.44; 95% CI, 1.34-1.54; p <0.001), neurofibromatosis type 2 (NF2; HR, 3.65; 95% CI, 1.28-10.39; p =0.0152), epidural SM (HR, 1.73; 95% CI, 1.09-2.75; p =0.0206), and malignant meningioma (HR, 2.64; 95% CI, 1.51-4.61; p <0.001) remained significantly associated to a reduced OS.

CONCLUSIONS

The SNDS is of great value in assessing SM incidence, associated mortality, and its predictors. OS after meningioma surgery is favorable but may be impaired for NF2 or older patients with a high level of comorbidities, epidural tumor, and malignant histopathology. SM surgery is not associated with an increased absolute excess mortality risk despite being performed on even more senior patients compared with intracranial meningioma.

Malignant anaplastic meningioma in neurofibromatosis type 1 patient: a rare case report

BACKGROUND

Meningiomas are usually associated with neurofibromatosis type 2 (NF-2), while gliomas are usually associated with neurofibromatosis type 1 (NF-1). NF-1 is an autosomal dominant genetic disorder associated with skin manifestations, bone conditions, and different types of benign and malignant tumors. Grade 3 anaplastic meningiomas are rare tumors with a poor prognosis. Systemic treatments in grade 3 meningiomas are experimental, with some reports suggestive of minimal clinical benefits. They are used occasionally for recurrent cases with no surgical or radiotherapy roles. In our case, we will focus the discussion on grade 3 anaplastic meningioma in a patient with NF-1, using chemotherapy for this aggressive, recurrent tumor. To our knowledge, this is the first case of NF-1 associated with malignant anaplastic meningioma in English literature.

CASE DESCRIPTION

In this case report, we present a 25-year-old left-handed female patient who fits the diagnostic criteria for NF-1. She presented with focal seizure and was diagnosed with grade 3 anaplastic meningioma, a highly aggressive tumor. She experienced a rapid recurrence after her initial surgery and eventually received multiple lines of treatments, including radiation and chemotherapy [temozolomide (TMZ)].

CONCLUSIONS

Systemic therapy in grade 3 meningiomas is still experimental and may have a slight clinical benefit. As a result, further prospective, multicentric studies are needed to ascertain these outcomes. Patients should be included in prospective trials because of the poor prognosis and aggressive nature of grade 3 meningiomas. In addition, discovering specific molecular biomarkers will allow us to suggest an individualized treatment. This case suggests that the differential diagnosis of a mass in a patient with NF-1 should include tumors known to be associated with the syndrome as well as sporadic, unrelated neoplasms.

Spinal meningiomas in pediatric patients – A case series and literature review

Background:

Meningiomas are the most frequent intracranial tumors in the adult population; however, they are rare in pediatric patients. In children, meningiomas often require further diagnosis of genetic comorbidities. As many as, 50% of young patients with meningiomas suffer from neurofibromatosis type 2 (NF2). Spinal meningiomas include only 10% of pediatric meningiomas.

Case Description:

Between 2000 and 2017, three children were hospitalized in the Neurosurgery Department. The patients reported prolonged periods of increasing neurological symptoms. In each case, a total gross tumor resection was performed. Histopathology result in each patient was meningioma psammomatosum. Only one girl required adjuvant radiotherapy (RTH) due to recurrent tumors. Magnetic resonance imaging (MRI) showed spinal nerves schwannomas and bilateral vestibular schwannomas in two patients with NF2.

Conclusion:

A slow tumor growth is characteristic of spinal meningiomas. Back pain is a frequent initial symptom of a slowly growing tumor mass. Subsequently, neurological deficits gradually increase. Patients require a long follow-up period and control MRI-scan. Children with diagnosed spinal meningioma should be strictly controlled because of the high risk of their developing other tumors associated with NF2. Surgical resection is the primary treatment modality of meningiomas. Adjuvant RTH should be recommended only for selected patients.

Type-2 Neurofibromatosis Patient with Parasagittal Meningioma: A Challenging Airway

The anesthetic management of a type-2 neurofibromatosis patient with a difficult airway is quite challenging. Such a situation tests the limits of the anesthesiologist's preparedness in maintaining the balance of the cerebral protection strategies and securing the airway. The anticipated challenges include managing the airway, controlling the raised intracranial pressure, and maintaining stable hemodynamics in anticipation of the expected blood loss. This article focuses on the preoperative airway evaluation and intraoperative preparedness in case of a patient with type-2 neurofibromatosis scheduled for craniotomy and excision of intracranial meningioma.

TRAF7 somatic mosaicism in a patient with bilateral optic nerve sheath meningiomas: illustrative case

BACKGROUND

In the past decade, next-generation sequencing has spurred significant progress in the understanding of cytogenetic alterations that occur in meningiomas. Eighty percent of adult meningiomas harbor pathogenic somatic variants involving NF2, TRAF7, SMARCB1, KLF4, PI3K, or POLR2A. Somatic variants in TRAF7 associated with meningiomas usually localize to the gene’s WD40 domains but are mutually exclusive to germline mutations, which cause a distinctive autosomal dominant syndrome.

OBSERVATIONS

This case involved a 15-year-old girl with bilateral optic nerve sheath meningiomas, diffuse meningiomatosis, and syndromic features, including craniosynostosis, brain anomalies, syndactyly, brachydactyly, epicanthus, and patent ductus arteriosus. Genetic testing of the meningioma specimen 7 years after biopsy showed a pathogenic p.R641C variant within the WD40 domain of the TRAF7 gene. Additional testing of unaffected tissues identified the same variant at lower allele frequencies, consistent with postzygotic somatic mosaicism.

LESSONS

The authors report postzygotic somatic mosaicism for a p.R641C variant in the TRAF7 gene in a patient with bilateral optic nerve sheath meningiomas, diffuse meningiomatosis and a constellation of systemic findings previously recognized in patients with germline mutations of this gene. This is the first report of optic nerve sheath meningioma in a patient with mutation in the TRAF7 gene.

Skull Base Meningiomas in Patients with Neurofibromatosis Type 2: An International Multicenter Study Evaluating Stereotactic Radiosurgery

Objective  Meningiomas are the second most common tumors in neurofibromatosis type 2 (NF-2). Microsurgery is challenging in NF-2 patients presenting with skull base meningiomas due to the intrinsic risks and need for multiple interventions over time. We analyzed treatment outcomes and complications after primary Gamma Knife radiosurgery (GKRS) to delineate its role in the management of these tumors. Methods  An international multicenter retrospective study approved by the International Radiosurgery Research Foundation was performed. NF-2 patients with at least one growing and/or symptomatic skull base meningioma and 6-month follow-up after primary GKRS were included. Clinical and radiosurgical parameters were recorded for analysis. Results  In total, 22 NF-2 patients with 54 skull base meningiomas receiving GKRS as primary treatment met inclusion criteria. Median age at GKRS was 38 years (10-79 years). Most lesions were located in the posterior fossa (55.6%). Actuarial progression free survival (PFS) rates were 98.1% at 2 years and 90.0% at 5 and 10 years. The median follow-up time after initial GKRS was 5.0 years (0.6-25.5 years). Tumor volume at GKRS was a predictor of tumor control. Lesions >5.5 cc presented higher chances to progress after radiosurgery ( p  = 0.043). Three patients (13.64%) developed adverse radiation effects. No malignant transformation or death due to meningioma or radiosurgery was reported. Conclusions  GKRS is effective and safe in the management of skull base meningiomas in NF-2 patients. Tumor volume deserve greater relevance during clinical decision-making regarding the most appropriate time to treat. GKRS offers a minimally invasive approach of particular interest in this specific group of patients.

Spinal biopsies: a clinicopathologic review of 53 cases diagnosed between 2011 and 2018 at a tertiary hospital in Kampala, Uganda

Background

Early diagnosis of spinal cord neoplasia serves patients from developing a number of complications and even death.

Methods

After obtaining ethical approval, retrospectively, a total of 53 tissue blocks of patients attended at the spinal ward were reviewed. Statistical analysis was done using SPSS version 20.0, and p value of less than 0.05 was applied to establish the existence of statistical significance between the compared categorical variables.

Results

The mean age of the patients was 30.7 ± 15.96 years. Most of the patients 32.1% (n = 17) were aged ≤ 19 years, and majority of the neoplasia 77.3% (n = 41) were extramedullary. Also, majority of the neoplasia 60.4% (n = 32) were benign and the malignant ones were 35.8% (n = 19). The mean duration of onset of symptoms for benign and malignant neoplasia in this study was 13.1 ± 16.4 and 3.4 ± 2.8 years, respectively, with statistical difference (95% CI 2.09–17.35, p = 0.014).

Conclusion

The patients with spinal cord neoplasia in the present study were of young age, and majority of them had benign neoplasia that were extramedullary located. The mean duration of onset of symptoms for patients with malignant neoplasia was significantly shorter than that of benign neoplasia.

Consensus core clinical data elements for meningiomas

BACKGROUND

With increasing molecular analyses of meningiomas, there is a need to harmonize language used to capture clinical data across centers to ensure that molecular alterations are appropriately linked to clinical variables of interest. Here the International Consortium on Meningiomas presents a set of core and supplemental meningioma-specific Common Data Elements (CDEs) to facilitate comparative and pooled analyses.

METHODS

The generation of CDEs followed the four-phase process similar to other National Institute of Neurological Disorders and Stroke (NINDS) CDE projects: discovery, internal validation, external validation, and distribution.

RESULTS

The CDEs were organized into patient- and tumor-level modules. In total, 17 core CDEs (10 patient-level and 7-tumour-level) as well as 14 supplemental CDEs (7 patient-level and 7 tumour-level) were defined and described. These CDEs are now made publicly available for dissemination and adoption.

CONCLUSIONS

CDEs provide a framework for discussion in the neuro-oncology community that will facilitate data sharing for collaborative research projects and aid in developing a common language for comparative and pooled analyses. The meningioma-specific CDEs presented here are intended to be dynamic parameters that evolve with time and The Consortium welcomes international feedback for further refinement and implementation of these CDEs.

Neurofibromatosis: Molecular Pathogenesis and Natural Compounds as Potential Treatments

The neurofibromatosis syndromes, including NF1, NF2, and schwannomatosis, are tumor suppressor syndromes characterized by multiple nervous system tumors, particularly Schwann cell neoplasms. NF-related tumors are mainly treated by surgery, and some of them have been treated by but are refractory to conventional chemotherapy. Recent advances in molecular genetics and genomics alongside the development of multiple animal models have provided a better understanding of NF tumor biology and facilitated target identification and therapeutic evaluation. Many targeted therapies have been evaluated in preclinical models and patients with limited success. One major advance is the FDA approval of the MEK inhibitor selumetinib for the treatment of NF1-associated plexiform neurofibroma. Due to their anti-neoplastic, antioxidant, and anti-inflammatory properties, selected natural compounds could be useful as a primary therapy or as an adjuvant therapy prior to or following surgery and/or radiation for patients with tumor predisposition syndromes, as patients often take them as dietary supplements and for health enhancement purposes. Here we review the natural compounds that have been evaluated in NF models. Some have demonstrated potent anti-tumor effects and may become viable treatments in the future.

Foramen Magnum Meningioma – A common histological tumor in a rare location

Meningiomas located in the foramen magnum area are uncommon. We report the case of a patient with a mass lesion compressing the medulla, who was admitted to the Neurology Department for cervical pain and tetraparesis. On the MRI (Magnetic Resonance Imaging) examination, specific features for a meningioma were described, confirmed later by the histopathological examination. The patient presented a favorable evolution, at only one month after surgery. Keywords: Meningioma, Tetraparesis, Foramen Magnum, Neurosurgery

High-Throughput Mechanistic Screening of Epigenetic Compounds for the Potential Treatment of Meningiomas

Background: Meningiomas are the most common primary central nervous system tumors. 20–30% of these tumors are considered high-grade and associated with poor prognosis and high recurrence rates. Despite the high occurrence of meningiomas, there are no FDA-approved compounds for the treatment of these tumors. Methods: In this study, we screened patient-cultured meningiomas with an epigenetic compound library to identify targetable mechanisms for the potential treatment of these tumors. Meningioma cell cultures were generated directly from surgically resected patient tumors and were cultured on a neural matrix. Cells were treated with a library of compounds meant to target epigenetic functions. Results: Although each tumor displayed a unique compound sensitivity profile, Panobinostat, LAQ824, and HC toxin were broadly effective across most tumors. These three compounds are broad-spectrum Histone Deacetylase (HDAC) inhibitors which target class I, IIa, and IIb HDACs. Panobinostat was identified as the most broadly effective compound, capable of significantly decreasing the average cell viability of the sample cohort, regardless of tumor grade, recurrence, radiation, and patient gender. Conclusions: These findings strongly suggest an important role of HDACs in meningioma biology and as a targetable mechanism. Additional validation studies are necessary to confirm these promising findings, as well to identify an ideal HDAC inhibitor candidate to develop for clinical use.

Peptide Receptor Radionuclide Therapy in Patients With Neurofibromatosis Type 2: Initial Experience

PURPOSE

Neurofibromatosis type 2 (NF2) is a genetic disorder that is associated with multiple tumors of the nervous system, and approximately one half of patients present with meningiomas. For patients with multifocal disease, somatostatin receptor-targeted peptide receptor radionuclide therapy (PRRT) might be a suitable systemic treatment option.

PATIENTS AND METHODS

Between March 2015 and August 2017, 11 NF2 patients (7 females and 4 males; mean age, 39 ± 12 years) with multifocal, progressive meningiomas underwent a median of 4 cycles of PRRT (range, 2-6 cycles). Acute and chronic adverse events were recorded according to National Institutes of Health's Common Toxicity Criteria (CTC) version 5.0. Follow-up MRIs (every 3 to 6 months), using the Response Assessment in Neuro-Oncology response criteria for meningiomas, were used to assess treatment responses.

RESULTS

Peptide receptor radionuclide therapy was well tolerated in all patients without any relevant acute adverse effects. Transient hematologic toxicity (CTC grade 3) was observed in 2 subjects. Somatostatin receptor-directed radiopeptide therapy resulted in radiological disease stabilization in 6 of 11 patients. Median progression-free survival was 12 months (range, 1-55 months), and overall survival was 37 months (range, 5-61 months).

CONCLUSIONS

Based on our retrospective pilot data, PRRT is feasible and well-tolerated in NF2 patients. It might offer a suitable treatment option in subjects with multiple, recurrent, or treatment-refractory meningiomas.

Telomerase Dysfunction in the Tumorigenesis of Genetic Disorders

Telomeres are nucleoprotein complexes present at the ends of chromosome to maintain its integrity. Telomere length is maintained by an enzyme called "telomerase". Thus, telomerase activity and telomere length are crucial for the initiation of cancer and tumors survival. Also, oxidative stress will cause DNA, protein, and/or lipid damage, which end with changes in chromosome instability, genetic mutation, and may affect cell growth and lead to cancer. Some genetic diseases such as chromosomal instability syndrome, overgrowth syndrome, and neurofibromatosis make the patients at higher risk for developing different types of cancers. Therefore, we aimed to estimate telomerase activity and oxidative stress in these patients. Blood samples were collected from 31 patients (10 with neurofibromatosis, 11 with chromosomal breakage, and 10 with overgrowth syndrome) and 12 healthy subjects. Blood hTERT mRNA was detected by real time quantitative reverse-transcription PCR (RT-qPCR). All patients were subjected to chromosomal examination and chromosome breakage study using diepoxybutane method. Moreover, serum glutathione (GSH), glutathione-s-transferase (GST) activity and nitric oxide (NO) levels were measured among the control and patients groups. Receiver operating characteristic (ROC) curve was drawn to evaluate the efficiency of telomerase activity as a biomarker for the prediction of cancer occurrence. The relative telomerase activity in neurofibromatosis patients was significantly higher than controls (P = 0.014), while it was non-significantly higher in chromosomal breakage and overgrowth patients (P = 0.424 and 0.129, respectively). NO levels in neurofibromatosis, chromosomal breakage and overgrowth patients significantly increased with respect to control (P = 0.021, 0.002, 0.050, respectively). GSH levels were non-significantly lower in neurofibromatosis and chromosomal breakage patients in comparison with the control group, while it remained unchanged in overgrowth patients. The GST activity was significantly upregulated in neurofibromatosis, chromosomal breakage and overgrowth groups in comparison with the control group (P = 0.001, 0.009, and 0.025, respectively). Chromosomal examination revealed normal karyotype in all four chromosomal breakage patients with positive diepoxybutane test. The results of the present study revealed altered telomerase activity and oxidative stress in the studied genetic disorders. More research studies with a larger number of patients are required to confirm whether this alteration is related to cancer occurrence risk or not.

Validation of a scoring system to evaluate the risk of rapid growth of intracranial meningiomas in neurofibromatosis type 2 patients

OBJECTIVE

Intracranial meningiomas occur in about half of neurofibromatosis type 2 (NF2) patients and are very frequently multiple. Thus, estimating individual meningiomas' growth rates is of great interest to tailor therapeutic interventions. The Asan Intracranial Meningioma Scoring System (AIMSS) has recently been published to estimate the risk of tumor growth in sporadic meningiomas. The current study aimed to determine predictors of rapid meningioma growth in NF2 patients and to evaluate the AIMSS score in a specific NF2 cohort.

METHODS

The authors performed a retrospective analysis of 92 NF2 patients with 358 measured intracranial meningiomas that had been observed prospectively between 2012 and 2018. Tumor volumes were measured at diagnosis and at each follow-up visit. The growth rates were determined and evaluated with respect to the clinicoradiological parameters. Predictors of rapid tumor growth (defined as growth ≥ 2 cm3/yr) were analyzed using univariate followed by multivariate logistic regression to build a dedicated predicting model. Receiver operating characteristic (ROC) curves to predict the risk of rapid tumor growth with the AIMSS versus the authors' multivariate model were compared.

RESULTS

Sixty tumors (16.76%) showed rapid growth. After multivariate analysis, a larger tumor volume at diagnosis (p < 0.0001), presence of peritumoral edema (p = 0.022), absence of calcifications (p < 0.0001), and hyperintense or isointense signal on T2-weighted MRI (p < 0.005) were statistically significantly associated with rapid tumor growth. It is particularly notable that the genetic severity score did not seem to influence the growth rate of NF2 meningiomas. In comparison with the AIMSS, the authors' multivariate model's prediction did not show a statistically significant difference (area under the curve [AUC] 0.82 [95% CI 0.76-0.88] for the AIMSS vs AUC 0.86 [95% CI 0.81-0.91] for the authors' model, p = 0.1).

CONCLUSIONS

The AIMSS score is valid in the authors' cohort of NF2-related meningiomas. It adequately predicted risk of rapid meningioma growth and could aid in decision-making in NF2 patients.

Inherited genetic syndromes and meningiomas

Meningiomas arising with inherited genetic syndromes occur nearly exclusively in the context of neurofibromatosis type 2 (NF2). NF2 is an autosomal dominant familial neoplasia syndrome that results from a mutation in the NF2 tumor suppressor gene located on the long arm of chromosome 22. The NF2 gene encodes for the protein merlin (moesin-ezrin-radixin-like protein), which has tumor suppressive effects that are reduced/inactivated in NF2-associated tumors. NF2-associated neoplasms affect the nervous system (schwannomas, meningiomas, ependymomas, astrocytomas, and neurofibromas) and skin. Other NF2 findings include ophthalmological lesions and peripheral neuropathy. Meningiomas are the second most frequent NF2-associated tumors (occurring in approximately half of all NF2 patients). They are often multiple and have unpredictable growth patterns. NF2-associated meningiomas can cause significant morbidity and mortality due to their location and a mass effect. Because of the multiplicity, frequent development of new tumors, and their protean nature, defined treatment strategies with serial surveillance is critical for optimal management of NF2-associated meningiomas. While surgical resection is the primary treatment for NF2-associated meningiomas, radiation plays an important adjunctive role in the management of recurrent and inoperable meningiomas.

YAP1-FAM118B Fusion Defines a Rare Subset of Childhood and Young Adulthood Meningiomas

Meningiomas are a central nervous system tumor primarily afflicting adults, with <1% of cases diagnosed during childhood or adolescence. Somatic variation in NF2 may be found in ∼50% of meningiomas, with other genetic drivers (eg, SMO, AKT1, TRAF7) contributing to NF2 wild-type tumors. NF2 is an upstream negative regulator of YAP signaling and loss of the NF2 protein product, Merlin, results in YAP overexpression and target gene transcription. This mechanism of dysregulation is described in NF2-driven meningiomas, but further work is necessary to understand the NF2-independent mechanism of tumorigenesis. Amid our institutional patient-centric comprehensive molecular profiling study, we identified an individual with meningioma harboring a YAP1-FAM118B fusion, previously reported only in supratentorial ependymoma. The tumor histopathology was remarkable, characterized by prominent islands of calcifying fibrous nodules within an overall collagen-rich matrix. To gain insight into this finding, we subsequently evaluated the genetic landscape of 11 additional pediatric and adolescent/young adulthood meningioma patients within the Children's Brain Tumor Tissue Consortium. A second individual harboring a YAP1-FAM118B gene fusion was identified within this database. Transcriptomic profiling suggested that YAP1-fusion meningiomas are biologically distinct from NF2-driven meningiomas. Similar to other meningiomas, however, YAP1-fusion meningiomas demonstrated overexpression of EGFR and MET. DNA methylation profiling further distinguished YAP1-fusion meningiomas from those observed in ependymomas. In summary, we expand the genetic spectrum of somatic alteration associated with NF2 wild-type meningioma to include the YAP1-FAM118B fusion and provide support for aberrant signaling pathways potentially targetable by therapeutic intervention.

Convexity Meningiomas in Patients with Neurofibromatosis Type 2: Long-Term Outcomes After Gamma Knife Radiosurgery

BACKGROUND

Convexity meningiomas are common tumors requiring treatment in patients with neurofibromatosis type 2 (NF2). Although different therapeutic options are described for sporadic convexity meningioma, much less is known about these lesions in patients with NF2 despite their distinct biology and need for multiple treatments. We analyzed the value of Gamma Knife radiosurgery (GKRS) as definitive treatment for convexity meningiomas in patients with NF2.

METHODS

This international multicenter retrospective study was approved by the International Radiosurgery Research Foundation. Patients with NF2 with at least 1 convexity meningioma and 6-month follow-up after primary GKRS were included.

RESULTS

Inclusion criteria were met by 18 patients with NF2. A total of 120 convexity meningiomas (median treatment volume, 0.66 cm3 [range, 0.10-21.20 cm3]) were analyzed. Median follow-up after initial GKRS was 15.6 years (range, 0.6-25.5 years). Median age at GKRS was 32.5 years (range, 16-53 years). Median number of meningiomas per patient was 13 (range, 1-27), and median number of convexity lesions receiving GKRS per patient was 3.5 (range, 1-27). One case of tumor progression was reported 24 years after GKRS, leading to actuarial progression-free survival rates of 100% at 2, 5, and 10 years. No malignant transformation or death due to meningioma or radiosurgery was recorded.

CONCLUSIONS

GKRS is safe and effective as definitive treatment of small to medium-sized convexity meningiomas in patients with NF2. Despite concerns about the particular mutational burden of these tumors, no malignant transformation manifested after treatment. GKRS represents a minimally invasive option that offers long-term tumor control to this specific group of patients.

Neurofibromatosis Type 2 (NF2) and the Implications for Vestibular Schwannoma and Meningioma Pathogenesis

Patients diagnosed with neurofibromatosis type 2 (NF2) are extremely likely to develop meningiomas, in addition to vestibular schwannomas. Meningiomas are a common primary brain tumor; many NF2 patients suffer from multiple meningiomas. In NF2, patients have mutations in the NF2 gene, specifically with loss of function in a tumor-suppressor protein that has a number of synonymous names, including: Merlin, Neurofibromin 2, and schwannomin. Merlin is a 70 kDa protein that has 10 different isoforms. The Hippo Tumor Suppressor pathway is regulated upstream by Merlin. This pathway is critical in regulating cell proliferation and apoptosis, characteristics that are important for tumor progression. Mutations of the NF2 gene are strongly associated with NF2 diagnosis, leading to benign proliferative conditions such as vestibular schwannomas and meningiomas. Unfortunately, even though these tumors are benign, they are associated with significant morbidity and the potential for early mortality. In this review, we aim to encompass meningiomas and vestibular schwannomas as they pertain to NF2 by assessing molecular genetics, common tumor types, and tumor pathogenesis.

A Practical Overview on the Molecular Biology of Meningioma

PURPOSE OF REVIEW

Meningioma is a common intracranial neoplasm currently classified in 15 histologic subtypes across 3 grades of malignancy. First-choice therapy for meningioma is maximum safe resection for grade I tumors, and surgery plus optional and mandatory adjuvant radiotherapy for grade II and III, respectively, given the increased rate of recurrence even in the event of complete resection. The WHO 2016 histopathologic grading of meningioma has been questioned due to subjectivity and its controversial predictive power for recurrence.

RECENT FINDINGS

Novel DNA methylation profiling has simplified classification into six classes that seem to improve prognostic accuracy. We review five main topics of molecular biology research regarding tumorigenesis and natural history of meningioma from the clinician's perspective: the histopathologic diagnostic features and pitfalls of the current tumor classification; the molecular integrated diagnosis supported by identification of genetic alterations and DNA methylation profiling; the general landscape of the various signaling pathways involved in meningioma formation; the pathogenic theories of the peri-tumoral edema present in meningioma and its therapy implications; and a summarized review on the current treatments and plausible targeted therapies directed to meningioma. It seems likely that molecular assessment will be introduced within the next update of the WHO classification of meningiomas, acknowledging the promising value of DNA methylation profiling. This integrated diagnostic protocol will simplify tumor subtype categorization and provide improved accuracy in predicting recurrence and outcome. Although much effort is being done in identifying key gene mutations, and elucidating specific intracellular signaling pathways involved in meningioma tumorigenesis, effective targeted therapies for recurrent meningiomas are still lacking.

The biological and diagnostic roles of MicroRNAs in meningiomas

MicroRNAs (miRNAs) refer to a class of small endogenous non-coding RNAs that regulate gene expression at the post-transcriptional level. Emerging studies have shown that miRNAs play critical roles in tumorigenesis and cancer progression. However, roles and mechanisms of miRNA dysregulation in the pathogenesis of meningioma are not fully understood. Here, we first reviewed existing research of aberrantly expressed miRNAs identified by high throughput microarray profiling in meningioma. We also explored the potential of miRNA as biomarkers and therapeutic targets for novel treatment paradigms of meningiomas. In addition, we summarized recent researches that focused on the possible mechanisms involved in miRNA-mediate meningioma occurrence and progression. This review provides an overview of miRNA deregulation in meningioma and indicates the potential of miRNAs to be used as biomarkers or novel therapeutic targets.

Body mass index, comorbidities, and hormonal factors in relation to meningioma in an ethnically diverse population: the Multiethnic Cohort

BACKGROUND

Meningioma is the most common intracranial tumor in the US and its etiology remains poorly understood. Meningioma has been predominantly studied among white populations. The aim of this study was to evaluate the associations of anthropometric, comorbidity, and hormonal factors with meningioma in an ethnically diverse population.

METHODS

A nested case-control analysis was performed within the Multiethnic Cohort (MEC). Meningioma cases were identified via linkage with Medicare and the California Office of Statewide Health Planning and Development Hospital Discharge data and were matched to up to 10 controls. Anthropometric, comorbidities, physical activity level, and hormonal factors at baseline based on questionnaires were evaluated for association with meningioma.

RESULTS

A total of 894 cases and 8918 matched controls were included in this study. Increasing body mass index (BMI) (P-trend = 0.041) and weight increases since age 21 (P-trend = 0.0052) were positively associated with meningioma. Hormonal factors including oral contraceptive use (odds ratio [OR]: 1.24; 95% CI: 1.01-1.51) and estrogen hormonal therapy use (per 5 years, OR: 1.07; 95% CI: 1.01-1.15) were associated with meningioma risk. Hypertension was positively associated with meningioma (OR: 1.26; 95% CI: 1.09-1.47), with individuals who reported a history of both hypertension and diabetes showing a stronger association (OR: 1.54; 95% CI: 1.17-2.03). The tests for heterogeneity across race/ethnicity were not statistically significant (P heterogeneity ≥ 0.17); however, the association of BMI with meningioma was mainly observed in Japanese Americans (P-trend = 0.0036) and hypertension in Japanese Americans (OR: 1.63; 95% CI: 1.17-2.27) and Native Hawaiians (OR: 1.86; 95% CI: 1.02-3.40).

CONCLUSION

Obesity, hormonal factors, and hypertension were associated with meningioma in an ethnically diverse population.

An update on the CNS manifestations of neurofibromatosis type 2

Neurofibromatosis type II (NF2) is a tumor predisposition syndrome characterized by the development of distinctive nervous system lesions. NF2 results from loss-of-function alterations in the NF2 gene on chromosome 22, with resultant dysfunction of its protein product merlin. NF2 is most commonly associated with the development of bilateral vestibular schwannomas; however, patients also have a predisposition to development of other tumors including meningiomas, ependymomas, and peripheral, spinal, and cranial nerve schwannomas. Patients may also develop other characteristic manifestations such as ocular lesions, neuropathies, meningioangiomatosis, and glial hamartia. NF2 has a highly variable clinical course, with some patients exhibiting a severe phenotype and development of multiple tumors at an early age, while others may be nearly asymptomatic throughout their lifetime. Despite the high morbidity associated with NF2 in severe cases, management of NF2-associated lesions primarily consists of surgical resection and treatment of symptoms, and there are currently no FDA-approved systemic therapies that address the underlying biology of the syndrome. Refinements to the diagnostic criteria of NF2 have been proposed over time due to increasing understanding of clinical and molecular data. Large-population studies have demonstrated that some features such as the development of gliomas and neurofibromas, currently included as diagnostic criteria, may require further clarification and modification. Meanwhile, burgeoning insights into the molecular biology of NF2 have shed light on the etiology and highly variable severity of the disease and suggested numerous putative molecular targets for therapeutic intervention. Here, we review the clinicopathologic features of NF2, current understanding of the molecular biology of NF2, particularly with regard to central nervous system lesions, ongoing therapeutic studies, and avenues for further research.

Clinical features of newly developed NF2 intracranial meningiomas through comparative analysis of pediatric and adult patients

OBJECTIVE

NF2 patients can develop new meningiomas throughout their lifetime. Little is known about the clinical features of newly developed NF2 meningiomas. In this study, we analyzed newly developed NF2 meningiomas in a large patient population.

PATIENTS AND METHODS

Among 452 NF2 patients, the location patterns of 81 pediatric and 939 adult NF2 meningiomas were compared to find the predominant locations of newly developed meningiomas in adulthood. The clinical features of 39 newly developed meningiomas in 24 NF2 patients were summarized. Clinical risk factors of NF2 meningioma growth rates were analyzed.

RESULTS

Pediatric patients had significantly more intracranial meningiomas than adult patients at the skull base (except for the petrosal region) (p < 0.0063). Adult patients had significantly more cranial meningiomas than pediatric patients at the parasagittal, parafalcine (middle & posterior), and frontal/parietal/cerebellar convex surfaces (p < 0.0063). Newly developed NF2 meningiomas in adults tended to occur at different locations than the locations of NF2 meningiomas in pediatric patients. New meningiomas could develop at various ages. Ninety-five NF2 patients were imaged and followed up for at least one year. Twenty-four patients (25.3 %) developed 39 new meningiomas during the follow-up period. They usually had initial meningiomas when new meningiomas occurred. The number of newly developed meningiomas per patient and the petrosal location were significantly associated with both the absolute and relative annual growth rates (p < 0.05).

CONCLUSIONS

The number of newly developed NF2 meningiomas seems to be a clinical marker of NF2 disease severity. In adults, new NF2 meningiomas tend to occur in patients with initial meningiomas. The predominant locations of newly developed NF2 meningiomas seem to be the parasagittal, parafalcine (middle/posterior), and frontal/parietal/cerebellar convex surfaces.

[Hereditary predisposition to tumors of the central and peripheral nervous systems]

Some tumors of the central and peripheral nervous system may be associated with a cancer predisposition syndrome, either hereditary or occurring de novo. Such a syndrome is usually associated with multiple tumors occurring early in life. Patients with neurofibromatosis type 1 present with multiple neurofibromas, especially of the plexiform type (which may transform into malignant peripheral nerve sheath tumor), and pilocytic astrocytomas of the optic pathways. Neurofibromatosis type 2 patients present with multiple schwannomas (typically bilateral vestibular schwannomas), meningiomas, and ependymomas. Li-Fraumeni syndrome (germline TP53 mutation) is associated with choroid plexus tumors (carcinomas), medulloblastomas, and diffuse astrocytomas. Multiple hemangioblastomas are characteristic of von Hippel-Lindau syndrome while subependymal giant cell astrocytomas are pathognomonic of tuberous sclerosis complex. Dysplastic cerebellar gangliocytomas of adult patients occur in Cowden syndrome. Turcot syndrome overlaps with constitutional mismatch repair deficiency syndrome (CMMRD), which is associated with giant cell glioblastomas. Rhabdoid tumor predisposition syndrome (germline mutation of SMARCB1/INI1) is associated with atypical teratoid/rhabdoid tumors. Tumors arising in the setting of a cancer predisposition syndrome develop along specific genetic pathways. Some histopathological and immunohistochemical characteristics of these tumors may point toward such a syndrome. The diagnosis of a cancer predisposition syndrome is of tremendous importance to the patients and their families who require genetic counseling and long-term follow-up.

Paediatric meningiomas in Singapore - Case series of a rare entity

Paediatric meningiomas are extremely rare. These tumours constitute only 2 to 3% of all childhood brain tumours. Despite similarities in histological features between PMs and their adult counterparts, there are important distinctions between them. In this case series, the authors describe their experience in paediatric meningiomas in Singapore's 2 children's hospitals from 1998 to 2018. The primary aim of this retrospective study is to evaluate the clinical, radiological and pathological characteristics, and associated outcomes of paediatric patients diagnosed with meningioma managed in our local institutions. Following that, the study's findings are secondary aims are corroborated with published literature. A total of 10 patients (4 males and 6 females) were identified for this study within the period of 01 January 1998 to 31 December 2018. Their ages ranged from 1 year old to 18 years old (median age 10.5 years old). Two of the patients had NF1 and NF2 respectively. There were 9 intracranial and 1 intraspinal paediatric meningiomas. Seven patients achieved gross total resection and 3 patients had subtotal resection. Eight patients did not have tumour recurrence or increase in size of tumour remnant during the course of their follow-up. In congruency with the literature, up to 40% of our patients had higher grade meningiomas and 55.6% had large tumour volumes more than 30 cm³. Owing to the paucity of knowledge for this unusual tumour, the authors emphasize the need for closer surveillance and in-depth genomic studies to identify novel therapies for this challenging condition.

Meningiomas in children

Meningiomas in children are poorly understood because they are rare. Recent reports have provided a more complete description of their incidence, genetics, imaging features, and outcome. In general, meningiomas in children are more likely to be higher grade, present in atypical locations, and have a higher risk of recurrence. The challenges encountered in children with respect to surgical and postoperative management are unique. Improved understanding of pediatric meningiomas, as well as the availability of new surgical, medical, and radiation therapies, creates opportunities to improve outcomes in this unique population.

Modern day imaging of meningiomas

Meningiomas are the most common primary tumors of the central nervous system and as such they are often encountered at neuroimaging. Fortunately, meningiomas are readily diagnosed with anatomic computed tomography and magnetic resonance imaging. While conventional imaging is the mainstay for initial diagnosis and delineating tumor for treatment planning and posttreatment follow-up, the last couple of decades have given rise to advanced physiologic and metabolic imaging techniques that serve as powerful tools in the management of meningioma. These modern approaches are allowing imaging to expand its utility to include extraction of biologic and potentially prognostic information that will ultimately improve care for meningioma patients.

Benign Intracranial Lesions - Radiotherapy: An Overview of Treatment Options, Indications and Therapeutic Results

BACKGROUND

Radiation Therapy (RT) is an established treatment option for benign intracranial lesions. The aim of this study is to display an update on the role of RT concerning the most frequent benign brain lesions and tumors.

METHODS

Published articles about RT and meningiomas, Vestibular Schwannomas (VSs), Pituitary Adenomas (PAs), Arteriovenous Malformations (AVMs) and craniopharyngiomas were reviewed and extracted data were used.

RESULTS

In meningiomas RT is applied as an adjuvant therapy, in case of patientrefusing surgery or in unresectable tumors. The available techniques are External Beam RT (EBRT) and stereotactic ones such as Stereotactic Radiosurgery (SRS), Fractionated Stereotactic RT (FSRT), Intensity Modulated RT (IMRT) and proton-beam therapy. The same indications are considered in PAs, in which SRS and FSRT achieve excellent tumor control rate (92-100%), acceptable hormone remission rates (>50%) and decreased Adverse Radiation Effects (AREs). Upon tumor growth or neurological deterioration, RT emerges as alone or adjuvant treatment against VSs, with SRS, FSRT, EBRT or protonbeam therapy presenting excellent tumor control growth (>90%), facial nerve (84-100%), trigeminal nerve (74-99%) and hearing (>50%) preservation. SRS poses an effective treatment modality of certain AVMs, demonstrating a 3-year obliteration rate of 80%. Lastly, a combination of microsurgery and RT presents equal local control and 5-year survival rate (>90%) but improved toxicity profile compared to total resection in case of craniopharyngiomas.

CONCLUSION

RT comprises an effective treatment modality of benign brain and intracranial lesions. By minimizing its AREs with optimal use, RT projects as a potent tool against such diseases.

Magnetic resonance imaging spectrum of spinal meningioma

PURPOSE

To evaluate magnetic resonance (MR) imaging findings of spinal meningioma and to determine the radiological subtypes based on the MR imaging findings and their respective clinical features.

MATERIAL AND METHODS

Data for 105 patients with surgically treated and histopathologically diagnosed spinal meningiomas at our hospital between May 1, 2003 and May 1, 2017 were evaluated in this study. Two radiologists reviewed the characteristics of spinal meningiomas on MR images and categorized the spinal meningiomas into subtypes based on MR imaging findings.

RESULTS

Most spinal meningiomas showed higher signal intensity than that of the spinal cord but lower than that of the subcutaneous fat on T2-weighted images (WI). 56 cases (54%) showed adjacent spinal cord signal changes. Meningiomas could be categorized according to MR imaging findings into type A: dural-based tumors with a homogeneous signal intensity and intense contrast enhancement (81 cases, 77%); type B: round or oval-shaped tumors with an internal hypointense portion on T2-weighted images (18 cases, 17%); type C: en plaque tumors (three cases, 3%); and type D: tumors with unusual findings and a heterogeneous appearance (three cases, 3%). All type C patients showed spinal cord signal changes.

CONCLUSIONS

Spinal meningioma showed slightly high signal intensity rather than high signal intensity on T2-weighted images. Spinal cord signal changes were present in more than half of the cases. Clinical differences were observed among the different MR imaging types.

Efficacy and Safety of Gamma Knife Radiosurgery for Meningiomas in Patients with Neurofibromatosis Type 2: A Long-Term Follow-Up Single-Center Study

OBJECTIVE

To explore the efficacy and safety of Gamma Knife radiosurgery (GKRS) for meningiomas in patients with neurofibromatosis type 2 (NF2).

METHODS

A series of 35 consecutive patients with 99 meningiomas in our department were retrospectively included from January 2000 to December 2015. Clinical records, magnetic resonance images, and follow-up data were reviewed.

RESULTS

A total of 35 patients (25 women and 10 men) with 99 NF2-associated meningiomas were identified. All patients initially received GKRS. The patients' median age at the time of GKRS was 40 years (range, 16-61 years). The median prescription dose at the tumor margin was 13 Gy (range, 12-15 Gy). The median follow-up time was 96 months (range, 25-224 months). Twenty-nine patients received GKRS only once, and 6 patients received it multiple times. Six patients (17.1%) had radiation-related complications 7.5 ± 2.4 months after GKRS. Local control rates at 1, 3, and 5 years were 100%, 97.1%, and 90.6%, respectively. Distant control rates at 1, 3, and 5 years were 88.5%, 55.9%, and 45.5%, respectively. Five patients died of concomitant neurologic symptoms. No malignant transformation was observed during the follow-up periods in all 35 patients.

CONCLUSIONS

GKRS represents an effective and safe management strategy with minimal invasion for patients with NF2-associated meningiomas. Our data showed a high local control rate of NF2-associated meningiomas by GKRS; however, the distant control rate is low, especially in young patients. For these patients, retreatment with GKRS may still be the advisable method.

Towards Molecular Classification of Meningioma: Evolving Treatment and Diagnostic Paradigms

Meningioma, a common primary brain tumor in adults, is graded based on World Health Organization criteria that rely on histology alone. This approach is unable to determine conclusively which tumors, especially benign or atypical, will recur. Molecular characterization of meningioma has identified genetic biomarkers that can predict tumor behavior. Only a few genetic changes are known to classify >85% of all meningioma and clinical trials using targeted therapy to genetic subtypes of meningioma are under way. Immunotherapy is also being trialed in treating high-grade and recurrent meningioma. This review summarizes recent developments characterizing meningioma using genetic and immunologic biomarkers and how these molecular tools may be integrated into existing care together with current World Health Organization grading to improve diagnosis, prognosis, and therapy.

A 42-year-old woman with subacute reversible dementia: A cautionary tale

A 42-year-old woman presented with a 6-month history of diffuse headache of moderate intensity and gradual onset of generalized weakness, imbalance, apathy, memory decline, hypophonia, dysphagia, constipation and urinary incontinence. Clinical examination revealed several elements of a frontal lobe dysfunction including apathy with motor impersistence, presence of primitive reflexes, generalized hyperreflexia with bilateral Hoffman sign and ankle clonus. The biological workup was unremarkable and a brain computed tomography scan identified a giant olfactory groove meningioma. A prompt neurosurgical intervention helped to reverse the symptoms. This case illustrates the benefits of actively looking for treatable conditions in young patients presenting with acute or subacute dementia and emphasizes the pivotal role of early brain imaging.