Tumor recurrence and malignant progression of gangliogliomas

Paediatric low-grade glioma: the role of classical pathology in integrated diagnostic practice

Low-grade gliomas are a cause of severe and often life-long disability in children. Pathology plays a key role in their management by establishing the diagnosis, excluding malignant alternatives, predicting outcomes and identifying targetable genetic alterations. Molecular diagnosis has reshaped the terrain of pathology, raising the question of what part traditional histology plays. In this review, we consider the classification and pathological diagnosis of low-grade gliomas and glioneuronal tumours in children by traditional histopathology enhanced by the opportunities afforded by access to comprehensive genetic and epigenetic characterisation.

Pan-cancer multi-omics analysis of PTBP1 reveals it as an inflammatory, progressive and prognostic marker in glioma

PTBP1 is an oncogene that regulates the splicing of precursor mRNA. However, the relationship between PTBP1 expression and gene methylation, cancer prognosis, and tumor microenvironment remains unclear. The expression profiles of PTBP1 across various cancers were derived from the TCGA, as well as the GTEx and CGGA databases. The CGGA mRNA_325, CGGA mRNA_301, and CGGA mRNA_693 datasets were utilized as validation cohorts. Immune cell infiltration scores were approximated using the TIMER 2.0 tool. Functional enrichment analysis for groups with high and low PTBP1 expression was conducted using Gene Set Enrichment Analysis (GSEA). Methylation data were predominantly sourced from the SMART and Mexpress databases. Linked-omics analysis was employed to perform functional enrichment analysis of genes related to PTBP1 methylation, as well as to conduct protein functional enrichment analysis. Single-cell transcriptome analysis and spatial transcriptome analysis were carried out using Seurat version 4.10. Compared to normal tissues, PTBP1 is significantly overexpressed and hypomethylated in various cancers. It is implicated in prognosis, immune cell infiltration, immune checkpoint expression, genomic variation, tumor neoantigen load, and tumor mutational burden across a spectrum of cancers, with particularly notable effects in low-grade gliomas. In the context of gliomas, PTBP1 expression correlates with WHO grade and IDH1 mutation status. PTBP1 expression and methylation play an important role in a variety of cancers. PTBP1 can be used as a marker of inflammation, progression and prognosis in gliomas.

Trends in referral patterns to presurgical evaluation at a European reference center

PURPOSE

To determine if growing evidence for epilepsy surgery as an early treatment option is reflected in the decrease of latencies between epilepsy onset and referral for presurgical evaluation METHODS: Retrospective analysis of latencies in 1646 patients (children and adults) from the time of epilepsy diagnosis to first presurgical workup in the period from 1999 to 2019 based on electronic patient charts at a tertiary epilepsy center. Time spans 1999-2009 and 2010-2019, prior to and following the ILAE definition of pharmacoresistance, and the role of etiological factors were assessed.

RESULTS

Over the whole period, the mean latency between diagnosis and a presurgical workup was 15.3 y. There was a significant reduction in the latencies between the periods 1999-2009 (16.9 y) and 2010-2019 (13.4 y), (p < 0.0001). In a linear regression analysis, the latency decreased by 2.6 months/year from 17.4 in 1999 to 13.1 y in 2019 (p < 0.001). Subgroup analyses showed significant decreases in latency to presurgical evaluation in patients with hippocampal sclerosis from 24.4 to 19.5 y, in malformations of cortical development from 16.4 to 13.2 y, and in nonlesional patients from 18.1 to 12.8 y, in contrast to patients with MR evidence for brain tumors with similar latencies across time (10.5 vs. 9.5 y, n.s.).

CONCLUSION

The reduction of the time span to a first presurgical evaluation was highly significant over time, yet moderate in its degree. Overall, the aim of early diagnostic evaluation for epilepsy surgery options after established pharmacoresistance was only achieved for a minority of patients.

DNA methylation-based classification of glioneuronal tumours synergises with histology and radiology to refine accurate molecular stratification

AIMS

Glioneuronal tumours (GNTs) are poorly distinguished by their histology and lack robust diagnostic indicators. Previously, we showed that common GNTs comprise two molecularly distinct groups, correlating poorly with histology. To refine diagnosis, we constructed a methylation-based model for GNT classification, subsequently evaluating standards for molecular stratification by methylation, histology and radiology.

METHODS

We comprehensively analysed methylation, radiology and histology for 83 GNT samples: a training cohort of 49, previously classified into molecularly defined groups by genomic profiles, plus a validation cohort of 34. We identified histological and radiological correlates to molecular classification and constructed a methylation-based support vector machine (SVM) model for prediction. Subsequently, we contrasted methylation, radiological and histological classifications in validation GNTs.

RESULTS

By methylation clustering, all training and 23/34 validation GNTs segregated into two groups, the remaining 11 clustering alongside control cortex. Histological review identified prominent astrocytic/oligodendrocyte-like components, dysplastic neurons and a specific glioneuronal element as discriminators between groups. However, these were present in only a subset of tumours. Radiological review identified location, margin definition, enhancement and T2 FLAIR-rim sign as discriminators. When validation GNTs were classified by SVM, 22/23 classified correctly, comparing favourably against histology and radiology that resolved 17/22 and 15/21, respectively, where data were available for comparison.

CONCLUSIONS

Diagnostic criteria inadequately reflect glioneuronal tumour biology, leaving a proportion unresolvable. In the largest cohort of molecularly defined glioneuronal tumours, we develop molecular, histological and radiological approaches for biologically meaningful classification and demonstrate almost all cases are resolvable, emphasising the importance of an integrated diagnostic approach.

Therapeutic potential of tumor treating fields for malignant brain tumors

BACKGROUND

Malignant brain tumors are among the most threatening diseases of the central nervous system, and despite increasingly updated treatments, the prognosis has not been improved. Tumor treating fields (TTFields) are an emerging approach in cancer treatment using intermediate-frequency and low-intensity electric field and can lead to the development of novel therapeutic options.

RECENT FINDINGS

A series of biological processes induced by TTFields to exert anti-cancer effects have been identified. Recent studies have shown that TTFields can alter the bioelectrical state of macromolecules and organelles involved in cancer biology. Massive alterations in cancer cell proteomics and transcriptomics caused by TTFields were related to cell biological processes as well as multiple organelle structures and activities. This review addresses the mechanisms of TTFields and recent advances in the application of TTFields therapy in malignant brain tumors, especially in glioblastoma (GBM).

CONCLUSIONS

As a novel therapeutic strategy, TTFields have shown promising results in many clinical trials, especially in GBM, and continue to evolve. A growing number of patients with malignant brain tumors are being enrolled in ongoing clinical studies demonstrating that TTFields-based combination therapies can improve treatment outcomes.

Glioneuronal and Neuronal Tumors of the Central Nervous System

Glioneuronal and neuronal tumors (GNTs) are rare neoplasms composed of neural and glial elements frequently located in the temporal lobe. Epilepsy is the main symptom and diagnosis mostly occurs before adulthood. The great majority of GNTs are WHO grade I tumors, but anaplastic transformations and forms exist. Their common association with focal cortical dysplasia is well recognized and should be taken into consideration during neurophysiological presurgical and surgical planning since the aim of surgery should be the removal of the tumor and of the entire epileptogenic zone according to anatomo-electrophysiological findings. Surgery still remains the cornerstone of symptomatic GNT, while radiotherapy, chemotherapy, and new target therapies are generally reserved for anaplastic, unresectable, or evolving tumors. Furthermore, since many GNTs show overlapping clinical and neuroradiological features, the definition of specific histopathological, genetic, and molecular characteristics is crucial. Epileptological, oncological, neurosurgical, and pathological issues of these tumors make a multidisciplinary management mandatory.

Preoperative Risk Stratification of Increased MIB-1 Labeling Index in Pituitary Adenoma: A Newly Proposed Prognostic Scoring System

The MIB-1 index is an important risk factor for progression-free survival (PFS) in pituitary adenoma (PA). Preoperatively, the MIB-1 index is not available in the decision-making process. A preoperative method regarding MIB-1 index estimation in PA has not been evaluated so far. Between 2011 and 2021, 109 patients with tumor morphology data, MIB-1 index data, and inflammatory and pituitary hormone laboratory values underwent surgery for PA. An MIB-1 index cutoff point (≥4/<4%) determines the probability of PFS in completely resected PA. An elevated MIB-1 index (≥4%) was present in 32 cases (29.4%) and was significantly associated with increased IGF-1, age ≤ 60, increased ACTH, and increased fibrinogen levels in the multivariable analysis. A scoring system (“FATE”) using preoperative IGF-1, age, ACTH, and plasma fibrinogen level enables the estimation of the MIB-1 index (sensitivity 72%, specificity 68%). The FATE score is also significantly associated with the time to PA progression after the complete resection of the PA. We propose the FATE score to preoperatively estimate the risk of an elevated MIB-1 index (≥4%), which might enable tailoring to medical decision-making, and follow-up interval scheduling, as well as inform future studies analyzing proliferative activities.

Predictive Power of MIB-1 vs. Mitotic Count on Progression-Free Survival in Skull-Base Meningioma

Simple Summary

Meningiomas are mainly benign intracranial tumors. Nevertheless, risk of recurrence exists in long-term follow-up, so new prognostic markers are still need to be identified. MIB-1 is no diagnostic criterion in WHO classification of meningiomas by now. This retrospective study shows that MIB-1 as well as mitotic count are good predictors for progression-free survival in skull-base meningiomas. The implantation of MIB-1 may enable an improved classification of meningiomas regarding progression-free survival. Moreover, this analysis of skull-base meningiomas shows that current cut-offs may have to be adjusted for meningioma location.

Abstract

Although meningiomas are mainly non-aggressive and slow-growing tumors, there is a remarkable recurrence rate in a long-term follow-up. Proliferative activity and progression-free survival (PFS) differs significantly among the anatomic location of meningiomas. The aim of the present study was to investigate the predictive power of MIB-1 labeling index and mitotic count (MC) regarding the probability of PFS in the subgroup of skull-base meningiomas. A total of 145 patients were included in this retrospective study. Histopathological examinations and follow-up data were collected. Ideal cut-off values for MIB-1 and MC were ≥4.75 and ≥6.5, respectively. MIB-1 as well as MC were good predictors for PFS in skull-base meningiomas. Time-dependent analysis of MIB-1 and MC in prediction of recurrence of skull-base meningioma showed that their prognostic values were comparable, but different cut-offs for MC should be considered regarding the meningioma’s location. As the achievement of a gross total resection can be more challenging in skull-base meningiomas and second surgery implies a higher risk profile, the recurrence risk could be stratified according to these findings and guide decision-making for follow-ups vs. adjuvant therapies.

Low-Dose Acetylsalicylic Acid Treatment in Non-Skull-Base Meningiomas: Impact on Tumor Proliferation and Seizure Burden

MIB-1 index is an important predictor of meningioma progression and was found to be correlated with COX-2 expression. However, the impact of low-dose acetylsalicylic acid (ASA) on MIB-1 index and clinical symptoms is unclear. Between 2009 and 2022, 710 patients with clinical data, tumor-imaging data, inflammatory laboratory (plasma fibrinogen, serum C-reactive protein) data, and neuropathological reports underwent surgery for primary cranial WHO grade 1 and 2 meningioma. ASA intake was found to be significantly associated with a low MIB-1 labeling index in female patients ≥ 60 years. Multivariable analysis demonstrated that female patients ≥ 60 years with a non-skull-base meningioma taking ASA had a significantly lower MIB-1 index (OR: 2.6, 95%: 1.0–6.6, p = 0.04). Furthermore, the intake of ASA was independently associated with a reduced burden of symptomatic epilepsy at presentation in non-skull-base meningiomas in both genders (OR: 3.8, 95%CI: 1.3–10.6, p = 0.03). ASA intake might have an anti-proliferative effect in the subgroup of elderly female patients with non-skull-base meningiomas. Furthermore, anti-inflammatory therapy seems to reduce the burden of symptomatic epilepsy in non-skull-base meningiomas. Further research is needed to investigate the role of anti-inflammatory therapy in non-skull-base meningiomas.

MAC-spinal meningioma score: A proposal for a quick-to-use scoring sheet of the MIB-1 index in sporadic spinal meningiomas

Objective

MIB-1 index is an important predictor of meningioma progression. However, MIB-1 index is not available in the preoperative tailored medical decision-making process. A preoperative scoring sheet independently estimating MIB-1 indices in spinal meningioma (SM) patients has not been investigated so far.

Methods

Between 2000 and 2020, 128 patients with clinical data, tumor imaging data, inflammatory laboratory (plasma fibrinogen, serum C-reactive protein) data, and neuropathological reports (MIB-1, mitotic count, CD68 staining) underwent surgery for spinal WHO grade 1 and 2 meningioma.

Results

An optimal MIB-1 index cut-off value (≥5/<5) predicting recurrence was calculated by ROC curve analysis (AUC: 0.83; 95%CI: 0.71-0.96). An increased MIB-1 index (≥5%) was observed in 55 patients (43.0%) and multivariable analysis revealed significant associations with baseline Modified McCormick Scale ≥2, age ≥65, and absence of calcification. A four-point scoring sheet (MAC-Spinal Meningioma) based on Modified McCormick, Age, and Calcification facilitates prediction of the MIB-1 index (sensitivity 71.1%, specificity 60.0%). Among those patients with a preoperative MAC-Meningioma Score ≥3, the probability of a MIB-1 index ≥5% was 81.3%.

Conclusion

This novel score (MAC-Spinal Meningioma) supports the preoperative estimation of an increased MIB-1 index, which might support preoperative patient-surgeon consultation, surgical decision making and enable a tailored follow-up schedule or an individual watch-and-wait strategy.

Seizure outcomes and prognostic factors in patients with gangliogliomas associated with epilepsy

Introduction

Ganglioglioma (GG) patients often present with seizures. Although most patients can be seizure-free after tumor resection, some still experience seizures. The present study aimed to analyze a group of GGs patients associated with epilepsy and evaluate the seizure outcomes and prognostic factors.

Methods

This retrospective study involved clinical data collected from medical records of patients diagnosed with GG pathologically and underwent surgical resection in Sanbo Brain Hospital, Capital Medical University. The seizure outcomes were evaluated based on the International League Against Epilepsy (ILAE) seizure outcome classification. The prognostic factors were identified according to univariate and multivariate analysis.

Results

A total of 222 patients were included, with a mean age at surgery of 19.19 ± 10.93 years. All patients were followed up at least for one year with a mean follow-up duration of 6.28 ± 3.17 years. At the final follow-up, 174 (78.4%) patients achieved ILAE Class 1 or 2. Univariate and multivariate analyses revealed that the short duration of seizures and gross total resection were significant positive factors for seizure-free. Bilateral interictal or ictal epileptiform discharges in preoperative video-electroencephalogram (VEEG) were related to poor seizure outcomes.

Conclusion

Surgical resection is an effective treatment for patients with epilepsy associated with GGs. The analysis of predictive factors could effectively guide clinical practice and evaluate the prognosis of epilepsy with GG.

Increased MIB-1 Labeling Index Is Associated with Abducens Nerve Morbidity in Primary Sporadic Petroclival Meningioma Surgery: Beyond Location and Approach

Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in patients who underwent the retrosigmoid approach in relation to the MIB-1 index. Thirty-two patients with primary sporadic PC MNG were retrospectively analyzed. Mean follow-up was 28.0 months. Analysis of the MIB-1 index was performed to evaluate the abducens nerve outcome. An optimal MIB-1 index cut-off value (<4/≥4) in the association with postoperative CN VI palsy was determined by ROC analysis (AUC: 0.74, 95% CI: 0.57−0.92). A new-onset CN VI palsy was present in 7 cases (21.88%) and was significantly associated with an increased MIB-1 index (≥4%, p = 0.025) and a peritumoral edema in the brachium pontis (p = 0.047) which might be caused by the increased growth rate. Tumor volume, cavernous sinus infiltration, auditory canal invasion, and Simpson grading were not associated with new CN VI deficits. Six (85.7%) of the 7 patients with both an increased MIB-1 index (≥4%) and new abducens nerve palsy still had a CN VI deficit at the 12-month follow-up. A peritumoral edema caused by a highly proliferative PC MNG with an elevated MIB-1 index (≥4%) is associated with postoperative abducens nerve deficits.

Inflammatory Tumor Microenvironment in Cranial Meningiomas: Clinical Implications and Intraindividual Reproducibility

The MIB-1 index was demonstrated to be significantly correlated to meningioma recurrence. However, to date, the relationship of the intraindividual course of the MIB-1 index and the growth fraction, respectively, to clinical tumor recurrence has not been demonstrated in cranial WHO grade 1 and 2 meningiomas. In the present paper, we compare the MIB-1 indices of 16 solely surgically treated primary meningiomas and their recurrent tumors regarding the course of the MIB-1 indices, time to recurrence, reproducibility and factors influencing the intraindividual MIB-1 indices. Regression analyses revealed (1) a strong intra-lab reproducibility (r = 0.88) of the MIB-1 index at the second versus the first operation, corresponding to a constant intrinsic growth activity of an individual meningioma, (2) a significant inverse correlation of both primary (r = −0.51) and secondary (r = −0.70) MIB-1 indices to time to recurrence, and (3) male sex, low plasma fibrinogen and diffuse CD68⁺ macrophage infiltrates contribute to an increase in the MIB-1 index. A strong intraindividual reproducibility of the MIB-1 index and a direct relationship of the MIB-1 index to the time to recurrence were observed. Individual MIB-1 indices might be used for tailored follow-up imaging intervals. Further research on the role of macrophages and inflammatory burden in the regrowth potential of meningiomas are needed.

Proliferative Potential, and Inflammatory Tumor Microenvironment in Meningioma Correlate with Neurological Function at Presentation and Anatomical Location-From Convexity to Skull Base and Spine

Emerging evidence emphasizes the prognostic importance of meningioma location. The present investigation evaluates whether progression-free survival (PFS), proliferative potential, World Health Organization (WHO) grades, and inflammatory burden differ between anatomical locations (skull base, non-skull base, and spinal) meningiomas. Five-hundred-forty-one patients underwent Simpson grade I or II resection for WHO grade 1 or 2 meningiomas. Univariable analysis revealed that spinal meningioma patients are significantly older, had a worse baseline Karnofsky Performance Status (KPS), higher acute-phase protein levels, lower incidence of WHO grade 2, lower mitotic counts, lower MIB-1 index, and less CD68+ macrophage infiltrates. Multivariable analysis identified WHO grade 2 (OR: 2.1, 95% CI: 1.1-3.7, p = 0.02) and cranial location (OR: 3.0, 95% CI: 1.8-4.9, p = 0.001) as independent predictors of diffuse CD68+ macrophage infiltrates. The mean PFS in cranial meningiomas was 115.9 months (95% CI: 107.5-124.3), compared to 162.2 months (95% CI: 150.5-174.0; log-rank test: p = 0.02) in spinal meningiomas. Multivariable Cox regression analysis revealed cranial location as an independent predictor (HR: 4.7, 95% CI: 1.0-21.3, p = 0.04) of shortened PFS. Increased MIB-1 indices ≥5% were significantly associated with location-specific deficits at presentation, such as decreased vision and seizure burden. Spinal meningiomas have a significantly longer PFS time and differ from the cranial meningiomas regarding MIB-1 index and density of tumor-associated macrophages.

A Whole-Slide Image Managing Library Based on Fastai for Deep Learning in the Context of Histopathology: Two Use-Cases Explained

Background: Processing whole-slide images (WSI) to train neural networks can be intricate and labor intensive. We developed an open-source library dealing with recurrent tasks in the processing of WSI and helping with the training and evaluation of neuronal networks for classification tasks. Methods: Two histopathology use-cases were selected and only hematoxylin and eosin (H&E) stained slides were used. The first use case was a two-class classification problem. We trained a convolutional neuronal network (CNN) to distinguish between dysembryoplastic neuroepithelial tumor (DNET) and ganglioglioma (GG), two neuropathological low-grade epilepsy-associated tumor entities. Within the second use case, we included four clinicopathological disease conditions in a multilabel approach. Here we trained a CNN to predict the hormone expression profile of pituitary adenomas. In the same approach, we also predicted clinically silent corticotroph adenoma. Results: Our DNET-GG classifier achieved an AUC of 1.00 for the ROC curve. For the second use case, the best performing CNN achieved an area under the curve (AUC) of 0.97 for the receiver operating characteristic (ROC) for corticotroph adenoma, 0.86 for silent corticotroph adenoma, and 0.98 for gonadotroph adenoma. All scores were calculated with the help of our library on predictions on a case basis. Conclusions: Our comprehensive and fastai-compatible library is helpful to standardize the workflow and minimize the burden of training a CNN. Indeed, our trained CNNs extracted neuropathologically relevant information from the WSI. This approach will supplement the clinicopathological diagnosis of brain tumors, which is currently based on cost-intensive microscopic examination and variable panels of immunohistochemical stainings.

Combining FORGE Score and Histopathological Diagnostic Criteria of Atypical Meningioma Enables Risk Stratification of Tumor Progression

More than 50% of atypical meningiomas regrow within 5 years after surgery. FORGE score is a newly created tool to estimate the MIB-1 index in cranial meningiomas. In this investigation, we aimed to assess the predictive value of the FORGE score in combination with major diagnostic criteria of atypical meningioma (brain invasion, mitotic count ≥ 4) regarding recurrence in atypical meningiomas. We included patients operated on primary atypical meningiomas in our center from 2011 to 2019. The study included 71 patients (58% women, median age 63 years). ROC curves revealed a superiority of FORGE score combined with histopathological diagnostic criteria of atypical meningioma (AT-FORGE) in the prediction of tumor progression compared to FORGE score only (AUC: 0.72; 95% CI: 0.54–0.91, cut-off: ≥5/<5, sensitivity: 75%, specificity: 78%). Patients with an AT-FORGE score ≥ 5 had a shorter time to tumor progression (32.8 vs. 71.4 months, p < 0.001) in the univariable analysis. Multivariable cox regression analysis revealed significant predictive value of Simpson grade > II, presence of multiple meningiomas and AT-FORGE score ≥ 5 for tumor progression. The combination of histopathological diagnostic criteria for atypical meningioma with FORGE score might facilitate an effective identification of patients with an atypical meningioma who have an increased risk of tumor progression.

Integrated genotype-phenotype analysis of long-term epilepsy-associated ganglioglioma

The BRAF p.V600E mutation is the most common genetic alteration in ganglioglioma (GG). Herein, we collected a consecutive series of 30 GG specimens from Xuanwu Hospital in order to corroborate the genetic landscape and genotype–phenotype correlation of this enigmatic and often difficult‐to‐classify epilepsy‐associated brain tumor entity. All specimens with histopathologically confirmed lesions were submitted to targeted next‐generation sequencing using a panel of 131 genes. Genetic alterations in three cases with histologically distinct tumor components, that is, GG plus pleomorphic xanthoastrocytoma (PXA), dysembryoplastic neuroepithelial tumor (DNT), or an oligodendroglioma (ODG)‐like tumor component, were separately studied. A mean post‐surgical follow‐up time‐period of 23 months was available in 24 patients. Seventy seven percent of GG in our series can be explained by genetic alterations, with BRAF p.V600E mutations being most prevalent (n = 20). Three additional cases showed KRAS p.Q22R and KRAS p.G13R, IRS2 copy number gain (CNG) and a KIAA1549‐BRAF fusion. When genetically studying different histopathology patterns from the same tumor we identified composite features with BRAF p.V600E plus CDKN2A/B homozygous deletion in a GG with PXA features, IRS2 CNG in a GG with DNT features, and a BRAF p.V600E plus CNG of chromosome 7 in a GG with ODG‐like features. Follow‐up revealed no malignant tumor progression but nine patients had seizure recurrence. Eight of these nine GG were immunoreactive for CD34, six patients were male, five were BRAF wildtype, and atypical histopathology features were encountered in four patients, that is, ki‐67 proliferation index above 5% or with PXA component. Our results strongly point to activation of the MAP kinase pathway in the vast majority of GG and their molecular‐genetic differentiation from the cohort of low‐grade pediatric type diffuse glioma remains, however, to be further clarified. In addition, histopathologically distinct tumor components accumulated different genetic alterations suggesting collision or composite glio‐neuronal GG variants.

Our results strongly point to activation of the MAP kinase pathway in the vast majority of ganglioglioma (GG).

Composite genetic alterations were found in cases with histologically distinct tumor components firstly, i.e. GG plus pleomorphic xanthoastrocytoma (PXA), dysembryoplastic neuroepithelial tumor, or an oligodendroglioma‐like tumor.

Seizure recurrence is inclined to ganglioglioma with atypical histopathology features (i.e. GG containing a ki‐67 proliferation index above 5% or GG with PXA component).

FORGE: A Novel Scoring System to Predict the MIB-1 Labeling Index in Intracranial Meningiomas

Simple Summary

Meningiomas are predominantly benign intracranial tumors, and surgical therapy represents the treatment of choice. However, the risk of recurrence and scheduling of follow-up intervals are significantly influenced by immunohistochemical items such as the MIB-1 labeling index. To date, it is not possible to integrate this essential information into the pre- or intraoperative surgical decision making. In the present study, we therefore analyzed baseline variables associated with the MIB-1 labeling index. We found four easily identifiable and routinely recorded risk factors for an increased MIB-1 index and developed a simple and quick-to-use score that allows us to estimate the risk of an elevated MIB-1 index prior to the surgical resection. Furthermore, this score seems to predict the progression-free survival in intracranial meningiomas. We believe that this score might us to more reliably guide patients in preoperative surgical strategy planning and postoperative follow-up scheduling.

Abstract

The MIB-1 index is an essential predictor of progression-free-survival (PFS) in meningioma. To date, the MIB-1 index is not available in preoperative treatment planning. A preoperative score estimating the MIB-1 index in patients with intracranial meningiomas has not been investigated so far. Between 2013 and 2019, 208 patients with tumor morphology data, MIB-1 index data, and plasma fibrinogen and serum C-reactive protein (CRP) data underwent surgery for intracranial WHO grade I and II meningioma. An optimal MIB-1 index cut-off value (≥6/<6) in the prediction of recurrence was determined by ROC curve analysis (AUC: 0.71; 95% CI: 0.55–0.87). A high MIB-1 index (≥6%) was present in 50 cases (24.0%) and was significantly associated with male sex, peritumoral edema, low baseline CRP, and low fibrinogen level in the multivariate analysis. A scoring system (“FORGE”) based on sex, peritumoral edema, preoperative CRP value, and plasma fibrinogen level supports prediction of the MIB-1 index (sensitivity 62%, specificity 79%). The MIB-1 labeling index and the FORGE score are significantly associated with an increased risk of poor PFS time. We suggest a novel score (“FORGE”) to preoperatively estimate the risk of an increased MIB-1 index (≥6%), which might help in surgical decision making and follow-up interval determination and inform future trials investigating inflammatory burden and proliferative activity.

A novel histopathological grading system for ganglioglioma

Gangliogliomas are central nervous system tumors located in the temporal lobe of young patients, frequently associated with epilepsy. In this paper, we propose a grading system based solely on histopathological criteria. We reevaluated all cases of ganglioglioma, atypical ganglioglioma, and anaplastic ganglioglioma diagnosed between 2011 and 2020 in the Pathology Department of the Emergency Clinical Hospital Bagdasar-Arseni, based on the type of glial mitoses, the number of neuronal and glial mitoses, presence of necrosis, microvascular proliferation, eosinophilic granular bodies, hypercellularity, presence and disposition of inflammatory infiltrate and atypical pleomorphism. Based on the proposed grading system, a score of 0–4 corresponded to a benign ganglioglioma, 5–9 to an atypical ganglioglioma, and 10–18 to an anaplastic ganglioglioma. The survival rates were 90% for benign ganglioglioma, 71.43% for atypical ganglioglioma, and 62.54% for anaplastic ganglioglioma. One case of benign ganglioglioma underwent a malignant transformation into anaplastic ganglioglioma, and recurrences were noticed in 28.57% of atypical ganglioglioma cases and 30.7% of all anaplastic gangliogliomas. The presence of rare glial mitoses and hypercellularity was correlated with mortality in cases of atypical ganglioglioma. We believe this histopathological scoring system could be used as a three-tier system to identify atypical ganglioglioma cases that are bound to have an aggressive course of evolution and require close follow-up. The other option would be to convert it to a two-tier grading system that can separate low-grade gangliogliomas from high-grade ones. The latter category can encompass both atypical and anaplastic ganglioglioma due to the high mortality of both entities.

Neuropathology of Surgically Managed Epilepsy Specimens

Epilepsy is characterized as recurrent seizures, and it is one of the most prevalent disorders of the human nervous system. A large and diverse profile of different syndromes and conditions can cause perturbations in neural networks that are associated with epilepsy. Advances in neuroimaging and electrophysiological monitoring have enhanced our ability to localize the neuropathological lesions that alter the neural networks giving rise to epilepsy, whereas advances in surgical management have resulted in excellent seizure control in many patients following resections. Histopathologic study using a variety of special stains, molecular analysis, and functional studies of these resected tissues has facilitated the neuropathological characterization of these lesions. Here, we review the neuropathology of common structural lesions that cause epilepsy and are amenable to neurosurgical resection, such as hippocampal sclerosis, focal cortical dysplasia, and its associated principal lesions, including long-term epilepsy-associated tumors, as well as other malformations of cortical development and Rasmussen encephalitis.

Giant Cerebellar Ganglioglioma Mimicking a Pilocytic Astrocytoma

A benign brain tumor, called a ganglioglioma (GG), can sometimes be found in the cerebrum. We describe an unusual pediatric case of GG in the cerebellum in this article. An 11-year-old male patient had a headache and epilepsy disorder. The head magnetic resonance imaging results revealed a giant cyst with an enhancing mural nodule in the right cerebellar hemisphere that flattened the fourth ventricle. Pilocytic astrocytoma was the provisional diagnosis based on clinical and imaging details. After radical mass eradication, a GG was demonstrated through histopathological analysis. Even though GG is an uncommon tumor, it should be included in the differential diagnosis for a cerebellar mass with both cystic and solid components in children.

[Features of the neuroradiological picture of ganglioglioma on the example of 20 clinical cases]

OBJECTIVE

To analyze the images obtained during pre-surgical neuroimaging in patients with gangliomas for the presence of specific signs and verification of the neoplastic process.

MATERIAL AND METHODS

The results of presurgical MRI (3.0, 1.5 Tesla) of 20 patients with gangliomas were analyzed to identify specific signs of a neuronal-glial tumor and verify the neoplastic process based on the results obtained and a review of the literature. In addition to high-resolution MRI (HR MRI), various protocol modifications were applied to patients with epileptogenic pathological substrates of unclear etiology, including tractography (DTI) and contrast-free MR perfusion (ASL). In 5 cases, a multi-modal study was performed that combined the results of CT, routine MRI, HR MRI, functional MRI (fMRI) in various combinations and PET CT.

RESULTS AND CONCLUSION

In 17 cases, patients underwent epileptic surgery. Three patients without epilepsy were operated on for a tumor diagnosed by radiological examination. In all 20 cases, gangliogliomas were verified, including 1 anaplastic, 1 infantile desmoplastic, and another patient had histological samples showing signs of a composite tumor. Combination with FCD IIIb was observed in 3 cases. Two patients had a double pathology (cases of tumors combination with lissencephaly and neuronal heterotopia) and another had a composite neuronal-glial tumor. In 15 cases, gangliogliomas showed neuroradiological features typical for dysembryoplastic neuroepithelial tumor (DNT) such as multicystic, nodular, and diffuse (dysplastic) described in the literature. In addition, in 9 cases, they had significant signs of neoplastic process such as contrast enhancement, continued growth and remodeling of the underlying bone. Verification of the neoplastic process based on the results of neuroradiological studies was difficult in 6 cases. In 2 cases, it was not possible to confirm the presence of neoplasm by radiological methods, and in 1 patient, the verification of the tumor during differential diagnosis took more than 8 years. The most common differential diagnosis was performed with DNT and FCD type IIb, which have a number of similar neuroradiological features.

Low-grade gangliogliomas in adults: A population-based study

BACKGROUND

Low-grade gangliogliomas (GGs) are rare tumors of the central nervous system in adults. This study aims to define their characteristics, prognostic factors, and the impact of different treatment patterns on survival.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to investigate the potential clinicopathological factors of low-grade GGs in adult patients (age ≥18 years). Kaplan-Meier method and Cox regression model were utilized to evaluate the associations between variables and overall survival (OS).

RESULTS

A total of 703 adult patients diagnosed with low-grade GGs were identified between 2004 and 2016, with a median follow-up period of 60.0 months. The median age at diagnosis was 32.0 years, with 50.1% of patients being male, 84.2% white people, and 40.2% of married status. The predominant tumor site was located in temporal lobe (38.8%). The median OS time for the whole cohort was not reached. The 5- and 10-year OS rates for patients underwent gross total resection (GTR) were 92.5% and 87.2%, respectively. Univariate and multivariate analysis showed age, gender, tumor site, and treatment pattern were significant factors for OS. The employment of adjuvant radiotherapy (RT) and/or chemotherapy would significantly shorten OS time.

CONCLUSIONS

This is the largest retrospective study of adult low-grade GGs up to date. Younger age, female gender, temporal lobe location, and GTR indicated better survival. Adjuvant RT and/or chemotherapy should not be considered after whatever surgery in adult patients with low-grade GGs, unless the malignant transformation has been confirmed.

Low-grade developmental and epilepsy associated brain tumors: a critical update 2020

Brain tumors represent the second most frequent etiology in patients with focal seizure onset before 18 years of age and submitted to epilepsy surgery. Hence, this category of brain tumors, herein defined as low-grade, developmental, epilepsy-associated brain tumors (LEAT) is different from those frequently encountered in adults as (A): 77% of LEAT occur in the temporal lobe; (B): the vast majority of LEAT are of low malignancy and classified as WHO I°; (C): LEAT are often composed of mixed glial and neuronal cell components and present with variable growth patterns including small cysts or nodules; (D): LEAT do not share common gene driving mutations, such as IDH1 or 1p/19q co-deletions. Characteristic entities comprise the ganglioglioma (GG), the dysembryoplastic neuroepithelial tumor (DNT), the angiocentric glioma (AG), the isomorphic diffuse glioma (IDG) and the papillary glio-neuronal tumor (PGNT), representing 73.2% of 1680 tumors collected in a large German series of 6747 patients submitted to epilepsy surgery. In the realm of exciting discoveries of genetic drivers of brain tumors new genes have been also reported for LEAT. BRAF V600E mutations were linked to GG with CD34 expression, FGFR1 mutations to DNT, MYB alterations to AG and also IDG and PRKCA fusions to PGNT, suggesting the possibility to also develop a genetically driven tumor classification scheme for LEAT. Rare availability of LEAT in a single center is a challenging obstacle, however, to systematically unravel the neurobiological nature and clinical behavior of LEAT. Other challenges in need of clarification include malignant tumor progression of LEAT entities, seizure relapse in patients following bulk tumor resection and the controversial issue of associated focal cortical dysplasia as additional pathomechanism. In order to advance our understanding and promote reliable diagnostic work-up of LEAT, we recommend, therefore, international collaboration to achieve our goals.

Somatostatin receptor expression and mTOR pathway activation in glioneuronal tumours of childhood

PURPOSE

To investigate the expression of somatostatin receptors (SSTRs) and markers of mTOR pathway in paediatric glioneuronal tumours and correlate these findings with tumour type, BRAFV600E mutational status and clinical characteristics such as tumour location, seizure frequency and duration, and age.

METHOD

37 children and adolescents with a neuropathological diagnosis of glioneuronal tumour were identified over a 22-year period. Immunohistochemical analyses for SSTRs type 1, 2A, 3, 5 and ezrin-radixin-moesin (ERM) and phosphorylated S6 (pS6), which are indicators of mTOR pathway activation, were performed in tumour specimens from 33 patients and evaluated using the immunoreactive score (IRS). The IRS were compared to tumour type, BRAFV600E status and clinical characteristics.

RESULTS

Ganglioglioma (GG) was the most frequently encountered subgroup (n = 27), followed by dysembryoplastic neuroepithelial tumour (DNET; n = 4). GGs expressed SSTR2A and SSTR3 to a high extent, 56 % and 44 % respectively. Expression of SSTR2A was also found in DNETs. Signs of mTOR pathway activation were abundant in GGs, but only present in one DNET. No correlations with BRAFV600E presence or clinical characteristics were found.

CONCLUSIONS

Expression of SSTRs and activation of mTOR pathway in paediatric glioneuronal tumour suggest that somatostatin analogues and mTOR inhibitors may have potential therapeutic implications in a subset of inoperable childhood glioneuronal tumours causing medically refractory epilepsy and/or tumour growth. Further clinical studies are warranted to validate these findings.

Long-term epilepsy-associated tumors: transcriptional signatures reflect clinical course

Long-term epilepsy-associated tumors (LEATs) represent mostly benign brain tumors associated with drug-resistant epilepsy. The aim of the study was to investigate the specific transcriptional signatures of those tumors and characterize their underlying oncogenic drivers. A cluster analysis of 65 transcriptome profiles from three independent datasets resulted in four distinct transcriptional subgroups. The first subgroup revealed transcriptional activation of STAT3 and TGF-signaling pathways and contained predominantly dysembryoplastic neuroepithelial tumors (DNTs). The second subgroup was characterized by alterations in the MAPK-pathway and up-stream cascades including FGFR and EGFR-mediated signaling. This tumor cluster exclusively contained neoplasms with somatic BRAF^V600E mutations and abundance of gangliogliomas (GGs) with a significantly higher recurrence rate (42%). This finding was validated by examining recurrent tumors from the local database exhibiting BRAF^V600E in 90% of the cases. The third cluster included younger patients with neuropathologically diagnosed GGs and abundance of the NOTCH- and mTOR-signaling pathways. The transcript signature of the fourth cluster (including both DNTs and GGs) was related to impaired neural function. Our analysis suggests distinct oncological pathomechanisms in long-term epilepsy-associated tumors. Transcriptional activation of MAPK-pathway and BRAF^V600E mutation are associated with an increased risk for tumor recurrence and malignant progression, therefore the treatment of these tumors should integrate both epileptological and oncological aspects.

High Mib-1-score correlates with new cranial nerve deficits after surgery for frontal skull base meningioma

Postoperative new cranial nerve deficits comprise severe concomitant morbidity in skull base meningioma surgery. Therefore, long-term cranial nerve integrity represents an important outcome measure. In the current study, we analyzed our institutional database in order to identify risk factors for postoperative new cranial nerve morbidity in the course of frontobasal meningioma surgery. Between 2009 and 2017, 195 patients were surgically treated for frontobasal meningioma at the authors' institution. Postoperative cranial nerve function was assessed immediately after surgery as well as 12 months postoperatively. A univariate and multivariate analysis was performed to identify factors influencing favorable postoperative cranial nerve outcome. Tumors with histological Mib-1-labeling indices > 5% were associated with a significantly higher percentage of new cranial nerve deficits immediately after surgery compared with those with Mib-1-labeling indices ≤ 5% (39% versus 20%, p = 0.029). Elevated Mib-1-labeling indices could be correlated with high CD68-positive macrophage staining (54% for Mib-1 index > 5% versus 19% for Mib-1 index ≤ 5%, p = 0.001). Elevated Mib-1-labeling index correlates with initial new cranial nerve dysfunction after resection of frontal skull base meningioma. With regard to elevated CD68-positive macrophage staining in high Mib-1-positive meningiomas, initial postoperative new cranial nerve morbidity might partly reflect macrophage-based inflammatory immune responses.

A case report of rare location of ganglioglioma

Background

Gangliogliomas are rare tumors of the central nervous system. They can occur anywhere in the central nervous system but are most commonly located in the temporal lobe and are mainly found in children. Anaplastic ganglioglioma can result from either de novo or transformation of a pre-existing lesion.

Case presentation

We report a case of de novo anaplastic ganglioglioma in the parieto occipital region, which is a rare location. A 34-year-old lady presented with features of raised intracranial pressure (ICP) with right side hemiparesis. Contrast-enhanced magnetic resonance imaging (CEMRI) of the brain showed well-defined intense heterogenously enhancing solid cystic mass lesion 5.3 × 5.2 cm in the left parieto occipital region with mass effect and midline shift. Intraoperatively, a cystic mass lesion with reddish brown nodule was seen in the left occipital lobe. Complete tumor excision was done. Microscopic and IHC examination was suggestive of anaplastic ganglioglioma. The post-operative period was uneventful. The patient received 60-Gy radiotherapy with temozolamide as adjuvant therapy, and repeat imaging showed no tumor recurrence.

Conclusion

Anaplastic gangliogliomas are rare tumors with parieto occipital as rare location.

Clinical Pearls and Advances in Molecular Researches of Epilepsy-Associated Tumors

Brain tumors are the second most common type of structural brain lesion that causes chronic epilepsy. Patients with low-grade brain tumors often experience chronic drug-resistant epilepsy starting in childhood, which led to the concept of long-term epilepsy-associated tumors (LEATs). Dysembryoplastic neuroepithelial tumor and ganglioglioma are representative LEATs and are characterized by young age of onset, frequent temporal lobe location, benign tumor biology, and chronic epilepsy. Although highly relevant in clinical epileptology, the concept of LEATs has been criticized in the neuro-oncology field. Recent genomic and molecular studies have challenged traditional views on LEATs and low-grade gliomas. Molecular studies have revealed that lowgrade gliomas can largely be divided into three groups : LEATs, pediatric-type diffuse low-grade glioma (DLGG; astrocytoma and oligodendroglioma), and adult-type DLGG. There is substantial overlap between conventional LEATs and pediatric-type DLGG in regard to clinical features, histology, and molecular characteristics. LEATs and pediatric-type DLGG are characterized by mutations in BRAF, FGFR1, and MYB/MYBL1, which converge on the RAS-RAF-MAPK pathway. Gene (mutation)-centered classification of epilepsyassociated tumors could provide new insight into these heterogeneous and diverse neoplasms and may lead to novel molecular targeted therapies for epilepsy in the near future.

Ganglioglioma with Cerebrospinal Fluid Rhinorrhea: A Rare Presentation

BACKGROUND

Gangliogliomas are low-grade gliomas, and patients generally present with seizures. Gangliogliomas commonly occur in the temporal lobe and predominantly occur in children. Malignant progression is rare.

CASE DESCRIPTION

A 26-year-old woman presented with a history of seizures since childhood and cerebrospinal fluid rhinorrhea for the past 6 months. Generally, patients with gangliogliomas seek early medical attention, as they present with dramatic complex partial seizures. This patient experienced seizures for 10 years and never sought medical attention during this time. She did not present for medical evaluation until she developed cerebrospinal fluid rhinorrhea.

CONCLUSIONS

This case gave us an opportunity to learn the natural history of ganglioglioma, although clinical presentations vary according to tumor location. This is the first case report to our knowledge of a patient with ganglioglioma presenting with cerebrospinal fluid rhinorrhea.

Prolonged Response Induced by Single Agent Vemurafenib in a BRAF V600E Spinal Ganglioglioma: A Case Report and Review of the Literature

Spinal ganglioglioma is a rare low-grade, slow-growing tumor of the central nervous system affecting mostly children and young adults. After surgery, some patients show tumor recurrence and/or malignant transformation. Gangliogliomas harbor molecular deficiencies such as mutations in the B-rapidly accelerated fibrosarcoma (BRAF) gene, resulting in activation of a downstream signaling pathway and cancer development. Vemurafenib is a BRAF inhibitor used to treat patients with BRAF V600E-mutated cancer. Although a few studies have reported the clinical responses in gangliogliomas, the sequence and duration of treatment have not been established. We describe a case of an adult with a progressive BRAF V600E mutant spinal cord ganglioglioma 9 years after surgery who was treated with vemurafenib. This treatment resulted in a partial response within 2 months, which was sustained for more than a year. The patient then decided to stop treatment because of side effects. Despite this decision, the tumor showed no sign of progression 21 months after treatment discontinuation. This is the first reported case of a response to vemurafenib in an adult with progressive spinal cord BRAF V600E-mutated ganglioglioma which was sustained after treatment discontinuation.

Review: Challenges in the histopathological classification of ganglioglioma and DNT: microscopic agreement studies and a preliminary genotype-phenotype analysis

Low-grade epilepsy-associated brain tumours (LEAT) are the second most common cause for drug-resistant, focal epilepsy, that is ganglioglioma (GG) and dysembryoplastic neuroepithelial tumours (DNT). However, molecular pathogenesis, risk factors for malignant progression and their frequent association with drug-resistant focal seizures remain poorly understood. This contrasts recent progress in understanding the molecular-genetic basis and targeted treatment options in diffuse gliomas. The Neuropathology Task Force of the International League Against Epilepsy examined available literature to identify common obstacles in diagnosis and research of LEAT. Analysis of 10 published tumour series from epilepsy surgery pointed to poor inter-rater agreement for the histopathology diagnosis. The Task Force tested this hypothesis using a web-based microscopy agreement study. In a series of 30 LEAT, 25 raters from 18 countries agreed in only 40% of cases. Highest discordance in microscopic diagnosis occurred between GG and DNT variants, when oligodendroglial-like cell patterns prevail, or ganglion cells were difficult to discriminate from pre-existing neurons. Suggesting new terminology or major histopathological criteria did not satisfactorily increase the yield of histopathology agreement in four consecutive trials. To this end, the Task Force applied the WHO 2016 strategy of integrating phenotype analysis with molecular-genetic data obtained from panel sequencing and 450k methylation arrays. This strategy was helpful to distinguish DNT from GG variants in all cases. The Task Force recommends, therefore, to further develop diagnostic panels for the integration of phenotype-genotype analysis in order to reliably classify the spectrum of LEAT, carefully characterize clinically meaningful entities and make better use of published literature.

Grading Gangliogliomas: a Short Case Series With Clinico-Imagistic and Immunohistopathological Correlations

OBJECTIVES

Ganglioglioma (GG) represents an extremely rare tumor of the central nervous system, which is composed of two different cellular populations: a glial cell population and a neuronal cell population, the former being the one which will establish the histologic grade of the tumor. The current World Health Organization (WHO) Classification of Tumors of the Central Nervous System divides gangliogliomas into benign (WHO grade I) and malignant (WHO grade III). Several scientific studies acknowledge that some tumors are difficult to grade but, due to the scarcity of cases as well as the lack of multicentric epidemiological data, there are no extensive studies regarding this matter in the neuropathology literature.

MATERIAL AND METHODS

We report a short case series of three patients with ganglioglioma who were admitted and treated at the Neurosurgery Department of "Bagdasar Arseni" Emergency Hospital. The patients had different clinical presentations, varying from migraines and epileptic seizures to development of a large, slowly growing tumor. Tissue fragments were obtained through surgical resection and sent to the Pathology Department for microscopic investigation.

OUTCOMES

Histopathologic examination revealed both components of the tumor, supporting the diagnosis of ganglioglioma, albeit the glial component featured different histologic grade in each tumor. The tumor diagnosed as grade II lacked mitoses, but showed conspicuous atypia and numerous multinucleated cells. Immunohistochemistry revealed immunoreactivity for synaptophysin, chromogranin A and neurofilament in the neuronal component and GFAP positivity in the glial component of the tumor. Neurofilament showed an unusual pattern of staining, in which areas with benign features showed patchy positivity, while areas with malignant features and striking nuclear pleomorphism were completely negative.

CONCLUSION

Due to the completely different clinical outcome, we strongly believe that a grade II ganglioglioma should be differentiated from a grade III GG, based on the lack of mitoses, necrosis and microvascular proliferation. The differentiation between grade II GG and grade I GG should be made on the cellular pleomorphism of both components (glial and neuronal). Based on our experience, we conclude that immunohistochemistry could aid in this differentiation through markers like: Ki67, neurofilament, CD34 and chromogranin A. We strongly believe that further immunohistochemical research on larger study groups will eventually lead to a consensus regarding definitive criteria for grade II gangliogliomas.

Ganglioglioma of the adenohypophysis mimicking pituitary adenoma: A case report and review of the literature

INTRODUCTION

Ganglioglioma is a generally benign tumor, mostly occurring in patients <30 years old. Temporal lobe is most frequently involved. Up to now, only 3 cases were reported of ganglioglioma in the pituitary gland, all being confined to the neurohypophysis. Here, we are the first to report an adenohypophysis ganglioglioma.

CASE PRESENTATION

A 43-year-old woman presented with chronic headache was referred to our hospital. Magnetic resonance imaging (MRI) indicated pituitary adenoma. Endoscopic transnasal transsphenoidal surgery was performed. The tumor was rich in blood supply, with tough texture, therefore only subtotal resection was conducted. Pathology analysis revealed an adenohypophysial tumor composed of dysplastic ganglion cells and neoplastic glial cells collided with nonspecific hyperplasia of pituitary cells. Immunohistochemistry revealed positive staining of synaptophysin, glial-fibrillary acidic protein, and CD34. The results were consistent with the diagnosis of ganglioglioma. After the surgery the patient recovered well except developing cerebrospinal fluid rhinorrhea, which was controlled by lumbar drainage. MRI 6 months later did not show any sign of progression.

CONCLUSION

According to the findings of our case, concerns should be raised considering ganglioglioma as a differential diagnosis of mass located in the sellar region. Furthermore, an ideal management strategy for pituitary ganglioglioma is not known; therefore, more cases and long-term follow-up are needed to enrich our knowledge of the diagnosis, treatment, and prognosis of this rare intracranial lesion.

Impact of surgery, adjuvant treatment, and other prognostic factors in the management of anaplastic ganglioglioma

BACKGROUND/PURPOSE

Anaplastic ganglioglioma (AGG) is a rare tumor with both glial and neuronal component accounting for less than 1% of all CNS tumors with limited information about the optimum treatment and outcome of these tumors.

METHOD AND MATERIALS

We did a thorough search of the PubMed with the following MesH terms: "Ganglioglioma; Anaplastic ganglioglioma; Ganglioglioma AND treatment; and Anaplastic ganglioglioma AND survival" to find all possible publications related to AGG to perform an individual patient data analysis and derive the survival outcome and optimum treatment of these tumors.

RESULTS

A total of 56 articles were retrieved pertaining to AGG with 88 patients. However, a total of 40 publications found eligible with 69 patients for individual patient data analysis. Median age for the entire cohort was 16 years (range 0.2-77 years). Surgical details were available for 64 patients. A gross total or near total resection was reported in 21 cases (32.8%), subtotal resection or debulking was reported in 25 cases (39.1%). Surgical details were available for 64 patients. A gross total or near total resection was reported in 21 cases (32.8%), and subtotal resection or debulking was reported in 25 cases (39.1%). Median overall survival (OS) was 29 months [95% CI 15.8-42.2 months] with 2- and 5-year OS 61 and 39.4% respectively.

CONCLUSION

AGG is associated with a dismal. Pediatric age and a gross total resection of tumor confer a better progression-free survival and OS. Hence, surgery should remain the cornerstone of therapy. However, because of modest survival, there is enough opportunity to improve survival with addition of adjuvant radiation and chemotherapy. A whole genome sequencing and molecular characterization would help to derive the best treatment option.

Cognition, health-related quality of life, and mood in children and young adults diagnosed with a glioneuronal tumor in childhood

AIMS

The aim of this study was to investigate long-term cognitive outcome, health-related quality of life (HRQoL), and psychiatric symptoms in children and young adults diagnosed with a glioneuronal tumor in childhood.

METHODS

Twenty-eight children and adolescents (0-17.99years) with a minimum postoperative follow-up time of five years were eligible for the study; four persons declined participation. A cross-sectional long-term follow-up evaluation was performed using the following study measures: Wechsler Intelligence Scale for Children (WISC-IV) or Wechsler Adult Intelligence Scale (WAIS-IV), Reys Complex Figure Test (RCFT), Short Form 36 version 2 (SF-36v2), Short Form 10 (SF-10), Quality of Life in Epilepsy 31 (QOLIE-31), Hospital Anxiety Depression Scale (HADS) or Beck Youth Inventory Scales (BYI), and Rosenberg Self-Esteem Scale. Historical WISC-III and RCFT data were used to compare cognitive longitudinal data.

RESULTS

Mean follow-up time after surgery was 12.1years. Sixty-three percent (15/24) were seizure-free. Despite a successive postoperative gain in cognitive function, a significant reduction relative to norms was seen in the seizure-free group with respect to perceptual reasoning index (PRI), working memory index (WMI), and full-scale intelligence quotient (FSIQ). Seizure freedom resulted in acceptable HRQoL. Thirty-two percent and 16% exceeded the threshold level of possible anxiety and depression, respectively, despite seizure freedom.

CONCLUSION

Although lower than in corresponding reference groups, cognitive outcome and HRQoL are good provided that seizure freedom or at least a low seizure severity can be achieved. There is a risk of elevated levels of psychiatric symptoms. Long-term clinical follow-up is advisable.

Response to the BRAF/MEK inhibitors dabrafenib/trametinib in an adolescent with a BRAF V600E mutated anaplastic ganglioglioma intolerant to vemurafenib

Efficacy of BRAF V600E targeted therapies in brain tumors harboring the mutation has been shown in several case reports and is currently being studied in larger clinical trials. Monotherapy with vemurafenib has been associated with significant side effects, including rashes, papillomas, and squamous cell carcinomas. Here we describe an adolescent female with anaplastic ganglioglioma and significant skin reaction to vemurafenib with subsequent tumor response and tolerance to the BRAF/MEK inhibitor combination of dabrafenib and trametinib without recurrence of previous reaction.

Natural course and prognosis of anaplastic gangliogliomas: a multicenter retrospective study of 43 cases from the French Brain Tumor Database

Background

Anaplastic gangliogliomas (GGGs) are rare tumors whose natural history is poorly documented. We aimed to define their clinical and imaging features and to identify prognostic factors.

Methods

Consecutive cases of anaplastic GGGs in adults prospectively entered into the French Brain Tumor Database between March 2004 and April 2014 were screened. After diagnosis was confirmed by pathological review, clinical, imaging, therapeutic, and outcome data were collected retrospectively.

Results

Forty-three patients with anaplastic GGG (median age, 49.4 y) from 18 centers were included. Presenting symptoms were neurological deficit (37.2%), epileptic seizure (37.2%), or increased intracranial pressure (25.6%). Typical imaging findings were unifocal location (94.7%), contrast enhancement (88.1%), central necrosis (43.2%), and mass effect (47.6%). Therapeutic strategy included surgical resection (95.3%), adjuvant radiochemotherapy (48.8%), or radiotherapy alone (27.9%). Median progression-free survival (PFS) and overall survival (OS) were 8.0 and 24.7 months, respectively. Three- and 5-year tumor recurrence rates were 69% and 100%, respectively. The 5-year survival rate was 24.9%. Considering unadjusted significant prognostic factors, tumor midline crossing and frontal location were associated with shorter OS. Temporal and parietal locations were associated with longer and shorter PFS, respectively. None of these factors remained statistically significant in multivariate analysis.

Conclusions

We report a large series providing clinical, imaging, therapeutic, and prognostic features of adult patients treated for an intracerebral anaplastic GGG. Our results show that pathological diagnosis is difficult, that survivals are only slightly better than for glioblastomas, and that complete surgical resection followed with adjuvant chemoradiotherapy offers longer survival.

Novel TLE4-NTRK2 fusion in a ganglioglioma identified by array-CGH and confirmed by NGS: Potential for a gene targeted therapy

Gangliogliomas are rare neoplasms of the central nervous system that mostly originate in the temporal lobe and are associated with seizures. Literature mentions that BRAF mutations are most commonly associated with gangliogliomas. We discuss a unique case of ganglioglioma originating in the posterior fossa that showed multiple losses and a unique interstitial deletion at 9q21 by an array-comparative genome hybridization (array-CGH). The deletion led to a novel molecular fusion (TLE4-NTRK2) which was confirmed by next generation sequencing and provides a potential for a gene-targeted therapy.

A case of adult anaplastic cerebellar ganglioglioma

Background:

Anaplastic posterior fossa ganglioglioma in adults is exceedingly rare. To date, only one case of adult anaplastic posterior fossa ganglioglioma has been reported in the English literature and none has been described at the cerebellum. To our knowledge, this report is the third case of malignant posterior fossa ganglioglioma in adults and the first at the cerebellum. In general, this entity can be misdiagnosed preoperatively as a primary posterior fossa neoplasm, and by reporting our clinical and radiographic observations we want to add to the existing literature on this rare entity.

Case Description:

A 40-year-old man presented with a history of headaches and dizziness and progressive gait disturbance and was diagnosed with anaplastic ganglioglioma in the posterior fossa.

Conclusions:

Although rare, our case demonstrates that anaplastic ganglioglioma should be considered in the differential diagnosis of infratentorial tumors in adult patients.

If it is Not a Glioblastoma, Then What is it? A Differential Diagnostic Review

As its historical name glioblastoma multiforme implies, glioblastoma is a histologically diverse, World Health Organization grade IV astrocytic neoplasm. In spite of its simple definition of presence of vascular proliferation and/or necrosis in a diffuse astrocytoma, the wide variety of cytohistomorphologic appearances overlap with many other neoplastic or non-neoplastic lesions. Here, after a brief review of glioblastoma is provided, the differential diagnostic possibilities with an emphasis on mimics and pitfalls are discussed. To provide an approach applicable to diagnostic practice, these discussions are grouped arbitrarily according to general malignant appearance such as pleomorphic xanthoastrocytoma and ganglioglioma, especially their anaplastic versions, and cellular features such as small cell and epithelioid glioblastoma. Some non-neoplastic lesions that can potentially be mistaken for glioblastoma under certain circumstances are also briefly mentioned. Additional studies, including immunohistochemistry and molecular markers, are included where applicable. Otherwise, exhaustive review of these individual entities, including their epidemiology and molecular biology, is outside the scope of this discussion.

Ganglioglioma Progression to Combined Anaplastic Ganglioglioma and Anaplastic Pleomorphic Xanthoastrocytoma. Case Report and Literature Review

BACKGROUND

Composite ganglioma and pleomorphic xanthoastrocytoma with anaplastic features in both components is an extremely rare glioneuronal tumor. Five cases of anaplastic progression in the glioma component have been reported. These tumors generally affect young patients who have brain tumor-related epilepsy, which are usually located in the temporal lobe or in the cerebellum and may have associated leptomeningeal spreading. Its current optimal treatment consists of maximal safe surgical resection and adjuvant chemoradiotherapy. Overall survival at 5 years is 33% in anaplastic pleomorphic xanthoastrocytoma and 53% in anaplastic ganglioglioma.

CASE DESCRIPTION

We describe a progression from ganglioglioma to this composite anaplastic entity after 32 months of follow-up, with apparently nontumoral parenchyma separating the 2 components. Polymerase chain reaction showed a wild-type BRAF gene. Seven months after concomitant chemoradiotherapy, radiologic progression led to a second line of chemotherapy, and a third line of chemotherapy was initiated after a subsequent progression at 11 months.

CONCLUSIONS

This case may add some evidence in favor of the glioneuronal maldevelopment hypothesis to explain the oncogenesis of these neuroepithelial tumors.

Long-term epilepsy-associated tumor in the amygdala of a 16-year-old boy: report of a rare case having intranuclear filaments

The term "long-term epilepsy-associated tumor (LEAT)" encompasses brain lesions associated with drug-resistant epilepsy over a long duration (≥2 years). Notably, some LEATs do not fit into any of the classifications of the World Health Organization (WHO). Herein, we report a LEAT that occurred in the left amygdala of a 16-year-old patient with intractable epilepsy. Histological examination of the resected amygdala revealed diffusely infiltrating tumor cells in the cortex. Perineuronal satellitosis and perivascular aggregation of tumor cells were apparent, along with mild nuclear enlargement and cytologic atypia. Tumor cells were positive for oligodendrocyte transcription factor 2 and neuronal markers including NeuN, neurofilaments, and synaptophysin, but were negative for CD34 and nestin. The most intriguing finding was intranuclear filaments, which appeared as rod- or needle-like shapes under high-power view. Ancillary ultrastructural analysis revealed thin filamentous intranuclear structures in tumor cells. Based on the glioneuronal nature of these cells as well as the infiltrative growth pattern, a diagnosis of LEAT was rendered that was deemed WHO grade I to II; however, the clinicopathological implications of the intranuclear inclusions remain unknown. The patient is currently alive and well without seizures.

Glioneuronal tumors in childhood - Before and after surgery. A long-term follow-up study

AIM

To give a detailed description of the long-term outcome of a cohort of children with glioneuronal tumors regarding pre- and postsurgical factors, including "dual" and "double" pathology, seizure freedom, and psychosocial outcome.

METHODS

During a fifteen-year period (1995-2009), all patients (age 0-17.99years) with a glioneuronal brain tumor diagnosed and treated at Uppsala University Children's Hospital were identified from the National Brain Tumor Registry and the National Epilepsy Surgery Registry. Hospital medical records were reviewed and neuroradiological and neuropathological findings were re-evaluated. A cross-sectional long-term follow-up prospective evaluation, including an interview, neurologic examination, and electroencephalogram, was accomplished in patients accepting participants in the study.

RESULTS

A total of 25 out of 28 (89%) eligible patients were included. The M:F ratio was 1.5:1. Mean follow-up time after surgery was 12.1years (range 5.0-19.3). Twenty patients were adults (>18years) at follow-up. Seizure freedom was achieved in 64%. Gross total resection (GTR) was the only preoperative factor significantly correlating to seizure freedom (p=0.027). Thirty-eight percent were at some time postoperatively admitted for a psychiatric evaluation. There was a trend towards both higher educational level and employment status in adults who became seizure free.

CONCLUSION

Long-term outcome is good regarding seizure freedom if GTR can be achieved, but late seizure recurrence can occur. "Dual" and "double" pathology is uncommon and does not influence seizure outcome. Obtaining seizure freedom seems to be important for psychosocial outcome, but there is a risk for psychiatric comorbidities and long-term follow-up by a multi-professional team is advisable.

Surgery for dysembryoplastic neuroepithelial tumors and gangliogliomas in eloquent areas. Functional results and seizure control

INTRODUCTION

Dysembryoplastic neuroepithelial tumors and gangliogliomas are developmental glioneuronal tumors usually revealed by partial epilepsy. High epileptogenicity, childhood epilepsy onset, drug-resistance, temporal location, and seizure freedom after complete resection are common characteristics of both tumors. We report the specificity of surgical management, functional results and seizure outcome in cases of a tumor location in eloquent areas.

METHODS

Among 150 patients (88 males, 3-55 years) operated on for refractory epilepsy due to a glioneuronal tumor (1990-2015), 30 (20%, dysembryoplastic neuroepithelial tumors=21; gangliogliomas=9) had a tumor located in an eloquent cortex (sensory-motor, insular or language areas). Surgery was performed after a preoperative work-up, including stereo-electroencephalography in 48 patients (26%) and functional MRI in 100 (67%). MRI-guided lesionectomy was mainly performed in extra-temporal location, whereas an additional corticectomy was performed in a temporal location. Tumor microsurgical resections were guided using neuronavigation and cortical/subcortical electrical stimulations. Multiple stereotactic thermocoagulations were performed in two insular tumors.

RESULTS

New motor/language deficits related to eloquent areas occurred postoperatively in 6/30 patients (20%) without any major permanent disability. Minor sensorimotor (n=2) and moderate language disturbance (n=1) persisted in three of them. Postoperative seizure-free outcome (mean follow-up>5 years) was obtained in 81% of the entire series, but significantly decreased to 60% in eloquent areas. Incomplete tumor resection was the main cause of surgical failure. However, unfavorable seizure outcome was also observed despite complete tumor resection. Malignant transformation occurred in one ganglioglioma.

CONCLUSION

Epilepsy surgery for benign glioneuronal tumors in eloquent areas provides acceptable results regarding the functional risks. Complete tumor resection is crucial for long-term favorable outcome.

Co-occurrence of histone H3 K27M and BRAF V600E mutations in paediatric midline grade I ganglioglioma

Ganglioglioma (GG) is a grade I tumor characterized by alterations in the MAPK pathway, including BRAF V600E mutation. Recently, diffuse midline glioma with an H3 K27M mutation was added to the WHO 2016 classification as a new grade IV entity. As co-occurrence of H3 K27M and BRAF V600E mutations has been reported in midline tumors and anaplastic GG, we searched for BRAF V600E and H3 K27M mutations in a series of 54 paediatric midline grade I GG (midline GG) to determine the frequency of double mutations and its relevance for prognosis. Twenty-seven patients (50%) possessed the BRAF V600E mutation. The frequency of the co-occurrence of H3F3A/BRAF mutations at diagnosis was 9.3%. No H3 K27M mutation was detected in the absence of the BRAF V600E mutation. Double-immunostaining revealed that BRAF V600E and H3 K27M mutant proteins were present in both the glial and neuronal components. Immunopositivity for the BRAF V600E mutant protein correlated with BRAF mutation status as detected by massARRAY or digital droplet PCR. The median follow-up of patients with double mutation was 4 years. One patient died of progressive disease 8 years after diagnosis, whereas the four other patients were all alive with stable disease at the last clinical follow-up (at 9 months, 1 year and 7 years) without adjuvant therapy. We demonstrate in this first series of midline GGs that the H3 K27M mutation can occur in association with the BRAF V600E mutation in grade I glioneuronal tumors. Despite the presence of H3 K27M mutations, these cases should not be graded and treated as grade IV tumors because they have a better spontaneous outcome than classic diffuse midline H3 K27M-mutant glioma. These data suggest that H3 K27M cannot be considered a specific hallmark of grade IV diffuse gliomas and highlight the importance of integrated histomolecular diagnosis in paediatric brain tumors.