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Aim Wallerian degeneration is a radiological finding thought to reflect corticospinal tract degeneration. This finding on magnetic resonance imaging (MRI) is routinely used as a predictor of poor prognosis in childhood stroke. However, its validity has never been established. Our objective was to correlate Wallerian degeneration seen on MRI with histopathology. Method We searched the databases of the Department of Pathology and Children's Stroke registry at the Hospital for Sick Children, Toronto for autopsy specimens exhibiting focal infarcts from children born at term who underwent MRI after a stroke. The specimens were examined for Wallerian degeneration and then correlated with the pre-mortem MRI findings. Results Seven children (four females, three males) with a median age of 11 years (1-17y) at the time of stroke met the inclusion criteria for this study. Of the seven children included in the study with ischaemic or haemorrhagic infarcts, six had concordant Wallerian degeneration findings on both MRI and post-mortem histopathological examination. The median time between stroke and death was 20 days (3-1825d). Interpretation Our results show for the first time that the radiographic finding of Wallerian degeneration is a valid biomarker of corticospinal tract degeneration in children who have had ischaemic or haemorrhagic stroke. [ABSTRACT FROM AUTHOR]

The Western blot technique is currently the standard detection method for suspected limb girdle muscular dystrophy (LGMD) 2A (calpainopathy). This is the first report in the English literature of the successful application of immunohistochemical techniques to support a diagnosis of LGMD 2A. This approach is straightforward and appears to be reasonably specific. We propose that immunohistochemical methods should be re-evaluated for the screening of undiagnosed patients with suspected LGMD 2A. [ABSTRACT FROM AUTHOR]

Introduction: Congenital muscular dystrophies (CMD) with hypoglycosylated α-dystroglycan due to POMT1 mutations are associated with clinical phenotypes that vary in severity. Methods: We describe a patient with congenital hypotonia, generalized weakness, elevated creatine kinase (CK), and normal brain imaging. Results: Histochemical analysis of the index case's muscle showed deficiency of glycosylated α-dystroglycan and secondary merosin deficiency. Genetic testing revealed a novel mutation in exon 20 of the POMT1 gene. Conclusions: Our patient's milder form of CMD adds to the emerging evidence of an expanding phenotype caused by POMT1 mutations. The histopathological findings of the muscle biopsy in this case support the need for careful clinical, genetic, and histochemical diagnostic interpretation. Muscle Nerve 45: 752-755, 2012 [ABSTRACT FROM AUTHOR]

Objective:: Primary angiitis of the central nervous system in childhood (cPACNS) is an immune-mediated inflammatory process directed toward blood vessels in the central nervous system. It has been associated with variable clinical and radiological presentations, and devastating consequences without treatment. Brain biopsy is required for definitive diagnosis. The objective of this study was to characterize the clinical and histopathological features of brain biopsies in small-vessel cPACNS (SVcPACNS). Methods:: A single-center prospective cohort study of children diagnosed with cPACNS from 1998 to 2008 was performed. All patients with negative cerebral angiography and brain biopsy were included. Patient data were reviewed for clinical, laboratory, and radiological characteristics at presentation. Standardized brain biopsy review protocols were established, with independent analysis by 2 neuropathologists. Histopathology was correlated with collected clinical data. Results:: A total of 13 SVcPACNS patients were included. Ages ranged from 5 to 17 years. Presenting features included seizures (85%), headache (62%), and cognitive decline (54%). Brain biopsy confirmed SVcPACNS in 11 patients with intramural lymphocytic infiltrate. Two had nonspecific perivascular inflammation only. All 6 nonlesional biopsies yielded a diagnosis of SVcPACNS. Lack of specific histological features correlated with prolonged time to biopsy, prior steroid treatment, and inadequate specimen sampling. Interpretation:: In children presenting with new onset severe headaches, seizures, or cognitive decline, SVcPACNS and brain biopsy should be considered. Lesional biopsies are preferred; however, nonlesional biopsies may succeed in yielding the diagnosis. Steroid treatment prior to biopsy and inadequate biopsy sampling may obscure the diagnosis in true cases of SVcPACNS. ANN NEUROL 2010;68:602-610 [ABSTRACT FROM AUTHOR]

Advances in our understanding of the biological basis and molecular characteristics of ependymal tumors since the latest iteration of the World Health Organization (WHO) classification of CNS tumors (2016) have prompted the cIMPACT‐NOW group to recommend a new classification. Separation of ependymal tumors by anatomic site is an important principle of the new classification and was prompted by methylome profiling data to indicate that molecular groups of ependymal tumors in the posterior fossa and supratentorial and spinal compartments are distinct. Common recurrent genetic or epigenetic alterations found in tumors belonging to the main molecular groups have been used to define tumor types at intracranial sites; C11orf95 and YAP1 fusion genes for supratentorial tumors and two types of posterior fossa ependymoma defined by methylation group, PFA and PFB. A recently described type of aggressive spinal ependymoma with MYCN amplification has also been included. Myxopapillary ependymoma and subependymoma have been retained as histopathologically defined tumor types, but the classification has dropped the distinction between classic and anaplastic ependymoma. While the cIMPACT‐NOW group considered that data to inform assignment of grade to molecularly defined ependymomas are insufficiently mature, it recommends assigning WHO grade 2 to myxopapillary ependymoma and allows grade 2 or grade 3 to be assigned to ependymomas not defined by molecular status. [ABSTRACT FROM AUTHOR]

cIMPACT‐NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to evaluate and make practical recommendations on recent advances in the field of CNS tumor classification, particularly in light of the rapid progress in molecular insights into these neoplasms. For Round 2 of its deliberations, cIMPACT‐NOW Working Committee 3 was reconstituted and convened in Utrecht, The Netherlands, for a meeting designed to review putative new CNS tumor types in advance of any future World Health Organization meeting on CNS tumor classification. In preparatory activities for the meeting and at the actual meeting, a list of possible entities was assembled and each type and subtype debated. Working Committee 3 recommended that a substantial number of newly recognized types and subtypes should be considered for inclusion in future CNS tumor classifications. In addition, the group endorsed a number of principles—relating to classification categories, approaches to classification, nomenclature, and grading—that the group hopes will also inform the future classification of CNS neoplasms. [ABSTRACT FROM AUTHOR]

We performed genome‐wide methylation analysis on 136 pediatric low‐grade gliomas, identifying a unique cluster consisting of three tumors with oligodendroglioma‐like histology, BRAF p.V600E mutations and recurrent whole chromosome gains of 7 and loss of 10. Morphologically, all showed similar features, including a diffusely infiltrative glioma composed of round nuclei with perinuclear halos, a chicken‐wire pattern of branching capillaries and microcalcification. None showed astrocytic features or characteristics suggestive of high‐grade tumors including necrosis or mitotic figures. All tumors harbored multiple chromosomal copy number abnormalities (>10 chromosomes altered), but none showed 1p/19q co‐deletion or IDH1 p.R132H mutation. Hierarchical clustering and t‐stochastic neighbor embedding analyses from DNA methylation data cluster them more closely to previously described pediatric‐type low‐grade gliomas and separate from adult gliomas. These tumors exhibit distinct clinical features; they are temporal lobe lesions occurring in adolescents and young adults with a prolonged history of seizures and all are alive with no recurrence (follow‐up 3.2 to 13.2 years). We encountered another young adult case with quite similar pathological appearance and molecular status except for TERT promoter mutation. Although the series is small, these may represent a new category of IDH wild‐type low‐grade gliomas which may be confused with "molecular GBM." Further, they highlight the heterogeneity of IDH wild‐type gliomas and the relatively indolent behavior of "pediatric‐type" gliomas. [ABSTRACT FROM AUTHOR]

cIMPACT‐NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to provide a forum to evaluate and recommend proposed changes to future CNS tumor classifications. From 2016 to 2019 (Round 1), cIMPACT published four updates. Update 1 clarified the use of the term NOS (Not Otherwise Specified) and proposed use of the additional term NEC (Not Elsewhere Classified). Update 2 issued clarifications regarding two diagnoses: Diffuse Midline Glioma, H3 K27M‐mutant and Diffuse Astrocytoma/Anaplastic Astrocytoma, IDH‐mutant. Update 3 proposed molecular criteria that could be used in the setting of an IDH‐wildtype diffuse or anaplastic astrocytic glioma without histological features of glioblastoma to infer that the tumor would behave similarly to a grade IV glioblastoma. Update 4 suggested that, in children and young adults, subtypes of IDH‐wildtype/H3‐wildtype diffuse gliomas may have distinct clinical features in the setting of a BRAFV600E mutation, FGFR1 alteration, other MAPK pathway alteration, or a MYB or MYBL1 rearrangement. The practical diagnostic relevance of these cIMPACT proposals is highlighted in this summary. [ABSTRACT FROM AUTHOR]

Background: Posterior fossa ependymoma (PFE) comprises 2 groups, PF group A (PFA) and PF group B (PFB), with stark differences in outcome. However, to the authors' knowledge, the long‐term outcomes of PFA ependymoma have not been described fully. The objective of the current study was to identify predictors of survival and neurocognitive outcome in a large consecutive cohort of subgrouped patients with PFE over 30 years. Methods: Demographic, survival, and neurocognitive data were collected from consecutive patients diagnosed with PFE from 1985 through 2014 at the Hospital for Sick Children in Toronto, Ontario, Canada. Subgroup was assigned using genome‐wide methylation array and/or immunoreactivity to histone H3 K27 trimethylation (H3K27me3). Results: A total of 72 PFE cases were identified, 89% of which were PFA. There were no disease recurrences noted among patients with PFB. The 10‐year progression‐free survival rate for all patients with PFA was poor at 37.1% (95% confidence interval, 25.9%‐53.1%). Analysis of consecutive 10‐year epochs revealed significant improvements in progression‐free survival and/or overall survival over time. This pertains to the increase in the rate of gross (macroscopic) total resection from 35% to 77% and the use of upfront radiotherapy increasing from 65% to 96% over the observed period and confirmed in a multivariable model. Using a mixed linear model, analysis of longitudinal neuropsychological outcomes restricted to patients with PFA who were treated with focal irradiation demonstrated significant continuous declines in the full‐scale intelligence quotient over time with upfront conformal radiotherapy, even when correcting for hydrocephalus, number of surgeries, and age at diagnosis (‐1.33 ± 0.42 points/year; P = .0042). Conclusions: Data from a molecularly informed large cohort of patients with PFE clearly indicate improved survival over time, related to more aggressive surgery and upfront radiotherapy. However, to the best of the authors' knowledge, the current study is the first, in a subgrouped cohort, to demonstrate that this approach results in reduced neurocognitive outcomes over time. In a subgroup‐specific manner, the results of the current study demonstrate that survival among patients with posterior fossa ependymoma has improved over time, and this improvement clearly is related to a change in practice with regard to pursuing aggressive surgical resections with upfront postoperative radiotherapy in all patients. This significant improvement highlights an urgent need for the implementation of early intervention and neuroprotective strategies. [ABSTRACT FROM AUTHOR]

Rhabdoid phenotype and loss of SMARCB1 expression in a brain tumor are characteristic features of atypical teratoid/rhabdoid tumors (ATRT). Rare non-rhabdoid brain tumors showing cribriform growth pattern and SMARCB1 loss have been designated cribriform neuroepithelial tumor (CRINET). Small case series suggest that CRINETs may have a relatively favorable prognosis. However, the long-term outcome is unclear and it remains uncertain whether CRINET represents a distinct entity or a variant of ATRT. Therefore, 10 CRINETs were clinically and molecularly characterized and compared with 10 ATRTs of each of three recently described molecular subgroups (i.e. ATRT-TYR, ATRT-SHH and ATRT-MYC) using Illumina Infinium HumanMethylation450 arrays, FISH, MLPA, and sequencing. Furthermore, outcome was compared to a larger cohort of 27 children with ATRT-TYR. Median age of the 6 boys and 4 girls harboring a CRINET was 20 months. On histopathological examination, all CRINETs demonstrated a cribriform growth pattern and distinct tyrosinase staining. On unsupervised cluster analysis of methylation data, all CRINETs examined exclusively clustered within the ATRT-TYR molecular subgroup. As ATRT-TYR, CRINETs mainly showed large heterozygous 22q deletions (9/10) and SMARCB1 mutations of the other allele. In two patients, SMARCB1 mutations were also present in the germline. Estimated mean overall survival in patients with CRINETs was 125 months (95% confidence interval 100-151 months) as compared to only 53 (33-74) months in patients with ATRTs of the ATRT-TYR subgroup (Log-Rank P < 0.05). In conclusion, CRINET represents a SMARCB1-deficient non-rhabdoid tumor, which shares molecular similarities with the ATRT-TYR subgroup but has distinct histopathological features and favorable long-term outcome. [ABSTRACT FROM AUTHOR]

Background: The determinants of outcomes for adult survivors of pediatric low-grade glioma (PLGG) are largely unknown.Methods: This study collected population-based follow-up information for all PLGG patients diagnosed in Ontario, Canada from 1985 to 2012 (n = 1202) and determined factors affecting survival. The impact of upfront radiation treatment on overall survival (OS) was determined for a cohort of Ontario patients and an independent reference cohort from the Surveillance, Epidemiology, and End Results database.Results: At a median follow-up of 12.73 years (range, 0.02-33 years), only 93 deaths (7.7%) were recorded, and the 20-year OS rate was 90.1% ± 1.1%. Children with neurofibromatosis type 1 had excellent survival and no tumor-related deaths during adulthood. Adverse risk factors included pleomorphic xanthoastrocytoma (P < .001) and a thalamic location (P < .001). For patients with unresectable tumors surviving more than 5 years after the diagnosis, upfront radiotherapy was associated with an approximately 3-fold increased risk of overall late deaths (hazard ratio [HR], 3.3; 95% confidence interval [CI], 1.6-6.6; P = .001) and an approximately 4-fold increased risk of tumor-related deaths (HR, 4.4; 95% CI, 1.3-14.6; P = .013). In a multivariate analysis, radiotherapy was the most significant factor associated with late all-cause deaths (HR, 3.0; 95% CI, 1.3-7.0; P = .012) and tumor-related deaths (HR, 4.4; 95% CI, 1.3-14.6; P = 0.014). A similar association between radiotherapy and late deaths was observed in the independent reference cohort (P < .001). In contrast to early deaths, late mortality was associated not with PLGG progression but rather with tumor transformation and non-oncological causes.Conclusions: The course of PLGG is associated with excellent long-term survival, but this is hampered by increased delayed mortality in patients receiving upfront radiotherapy. These observations should be considered when treatment options are being weighed for these patients. [ABSTRACT FROM AUTHOR]

The precise genetic cause remains elusive in nearly 50% of patients with presumed neurogenetic disease, representing a significant barrier for clinical care. This is despite significant advances in clinical genetic diagnostics, including the application of whole-exome sequencing and next-generation sequencing-based gene panels. In this study, we identify a deep intronic mutation in the DMD gene in a patient with muscular dystrophy using both conventional and RNAseq-based transcriptome analyses. The implications of our data are that noncoding mutations likely comprise an important source of unresolved genetic disease and that RNAseq is a powerful platform for detecting such mutations. [ABSTRACT FROM AUTHOR]

BACKGROUND The cure rate for childhood intracranial ependymoma is approximately 70% in the setting of a gross total resection followed by radiation, but management remains challenging in patients with residual disease. Therefore, robust biomarkers are needed to guide the development of new targeted therapy. The authors evaluated the expression of several biomarkers in pediatric intracranial ependymoma and observed that the expression of enhancer of zeste homolog 2 (EZH2), a polycomb complex protein involved in epigenetic regulation of gene expression, was independently associated with poor survival. METHODS Tissue microarray immunostaining was performed on 180 ependymoma samples from 12 of 16 Canadian pediatric centers. Expression levels of EZH2, Ki-67, B lymphoma Moloney-murine leukemia virus insertion region 1 homolog, tumor protein 16 (P16), Y-box binding protein 1, phosphorylated protein kinase B (pAKT), and epidermal growth factor receptor were evaluated. Cox regression analyses were performed, and the Kaplan-Meier method was used to construct survival curves. RESULTS EZH2 expressed in 16% of tumors was associated with inferior 5-year overall survival. Ki-67 and pAKT levels were associated with a poor outcome in patients with posterior fossa ependymoma, and the absence of P16 was associated with a poor outcome in patients with supratentorial ependymoma. Multivariate analysis revealed that younger age and EZH2 expression (95% confidence interval, 1.1-36.0) were independent markers of a poor prognosis. CONCLUSIONS EZH2 is a novel, independent marker of a poor prognosis in patients with ependymoma, especially in those who have tumors located in the posterior fossa. EZH2, pAKT, and P16 are potential therapeutic targets, particularly for patients who have tumors in which standard gross total resection plus fractionated radiotherapy is not feasible. Cancer 2015;121:1499-1507. © 2015 American Cancer Society. [ABSTRACT FROM AUTHOR]

Objective Astrocytic inclusions ( AIs) have been identified on histologic specimens of patients with early onset seizures, and the proteomic contents have been described. The aim of this study was to compare the clinical, electroencephalography ( EEG), magnetoencephalography ( MEG), magnetic resonance imaging ( MRI), and surgical outcomes of AIs relative to focal cortical dysplasia ( FCD). Methods We assessed the clinical manifestations, semiology, ictal and interictal features on video- EEG, MEG, MRI features, and surgical outcomes of children with histologically proven AIs compared to FCD. Results Six children had AIs and 27 had FCD. Children with AIs had an earlier age at seizure onset, periodic spasms (all children), and interictal epileptiform discharges consisting of a mixture of generalized or diffuse hemispheric slow waves, sharp waves, spikes and polyspikes. Children with FCD were less likely to have spasms (4/27 [15%]), and the morphology of the diffuse hemispheric or generalized discharges were different from those of AI, consisting of spike-and-waves, polyspike-and-waves, sharp-and-slow waves, and paroxysmal fast activity. Patients with AIs were less likely to have tightly clustered MEG spike sources (3/6 [50%] vs. 23/27 [85%]), and more likely to demonstrate abnormal sulcation and gyration pattern (4/6 [67%] vs. 2/27 [7%]) and gray matter heterotopia (2/6 [33%] vs. 0/27 [0%]) than patients with FCD. Four children with AIs had resection and two had biopsy but did not undergo resection. Children with AIs had lower rates of seizure freedom after surgery compared to FCD (1/4 [25%] vs. 15/27 [56%], respectively). Significance Although there were some similarities between AIs and FCD, patients with AIs were more likely to present with early onset periodic spasms, have unusual interictal epileptiform discharges, abnormal sulcation, gyration pattern, and gray matter heterotopia, and were less likely to be seizure free following surgical resection relative to FCD. Further study with a larger sample size is needed to validate our findings. [ABSTRACT FROM AUTHOR]

Major discoveries in the biology of nervous system tumors have raised the question of how non-histological data such as molecular information can be incorporated into the next World Health Organization (WHO) classification of central nervous system tumors. To address this question, a meeting of neuropathologists with expertise in molecular diagnosis was held in Haarlem, the Netherlands, under the sponsorship of the International Society of Neuropathology (ISN). Prior to the meeting, participants solicited input from clinical colleagues in diverse neuro-oncological specialties. The present "white paper" catalogs the recommendations of the meeting, at which a consensus was reached that incorporation of molecular information into the next WHO classification should follow a set of provided "ISN-Haarlem" guidelines. Salient recommendations include that (i) diagnostic entities should be defined as narrowly as possible to optimize interobserver reproducibility, clinicopathological predictions and therapeutic planning; (ii) diagnoses should be "layered" with histologic classification, WHO grade and molecular information listed below an "integrated diagnosis"; (iii) determinations should be made for each tumor entity as to whether molecular information is required, suggested or not needed for its definition; (iv) some pediatric entities should be separated from their adult counterparts; (v) input for guiding decisions regarding tumor classification should be solicited from experts in complementary disciplines of neuro-oncology; and (iv) entity-specific molecular testing and reporting formats should be followed in diagnostic reports. It is hoped that these guidelines will facilitate the forthcoming update of the fourth edition of the WHO classification of central nervous system tumors. [ABSTRACT FROM AUTHOR]

Major discoveries in the biology of nervous system tumors have raised the question of how non-histological data such as molecular information can be incorporated into the next World Health Organization ( WHO) classification of central nervous system tumors. To address this question, a meeting of neuropathologists with expertise in molecular diagnosis was held in Haarlem, the Netherlands, under the sponsorship of the International Society of Neuropathology ( ISN). Prior to the meeting, participants solicited input from clinical colleagues in diverse neuro-oncological specialties. The present 'white paper' catalogs the recommendations of the meeting, at which a consensus was reached that incorporation of molecular information into the next WHO classification should follow a set of provided ' ISN- Haarlem' guidelines. Salient recommendations include that (i) diagnostic entities should be defined as narrowly as possible to optimize interobserver reproducibility, clinicopathological predictions and therapeutic planning; (ii) diagnoses should be 'layered' with histologic classification, WHO grade and molecular information listed below an 'integrated diagnosis'; (iii) determinations should be made for each tumor entity as to whether molecular information is required, suggested or not needed for its definition; (iv) some pediatric entities should be separated from their adult counterparts; (v) input for guiding decisions regarding tumor classification should be solicited from experts in complementary disciplines of neuro-oncology; and (iv) entity-specific molecular testing and reporting formats should be followed in diagnostic reports. It is hoped that these guidelines will facilitate the forthcoming update of the fourth edition of the WHO classification of central nervous system tumors. [ABSTRACT FROM AUTHOR]

Maturation in central nervous system embryonal tumors is an uncommon phenomenon that is mainly reported in the context of specific histological subgroups of medulloblastoma. In this report we describe two cases of histological maturation in patients with supratentorial primitive neuroectodermal tumor with strikingly different outcomes. We discuss the potential impact of such findings on treatment and outcome. [ABSTRACT FROM AUTHOR]

Pediatric high-grade astrocytomas ( HGAs) account for 15-20% of all pediatric central nervous system tumors. These neoplasms predominantly involve the supratentorial hemispheres or the pons-diffuse intrinsic pontine gliomas ( DIPG). Assumptions that pediatric HGAs are biologically similar to adult HGAs have recently been challenged, and the development of effective therapeutic modalities for DIPG and supratentorial HGA hinges on a better understanding of their biological properties. Here, 20 pediatric HGAs (9 DIPGs and 11 supratentorial HGAs) were subject to gene expression profiling following approval by the research ethics board at our institution. Many of these tumors showed expression signatures composed of genes that promote G1/S and G2/M cell cycle progression. In particular, Aurora kinase B ( AURKB) was consistently and highly overexpressed in 6/9 DIPGs and 8/11 HGAs. Array data were validated using quantitative real-time PCR and immunohistochemistry, as well as cross-validation of our data set with previously published series. Inhibition of Aurora B activity in DIPG and in pediatric HGA cell lines resulted in growth arrest accompanied by morphological changes, cell cycle aberrations, nuclear fractionation and polyploidy as well as a reduction in colony formation. Our data highlight Aurora B as a potential therapeutic target in DIPG. [ABSTRACT FROM AUTHOR]

Summary Cerebral hyaline astrocytic inclusions have been observed in a subset of patients with early onset epilepsy, brain structural anomalies, and developmental delay, which indicates that it may represent a unique clinicopathologic entity. To further characterize this condition we use proteomics to investigate differentially expressed proteins in epileptic brain tissue from three pediatric epileptic patients with cerebral hyaline astrocytic inclusions, ranging in age from 5-13 years, and compare to brain tissue from two normal controls. Catalase and carbonic anhydrase I both exhibited increased expression in epileptic brain tissue compared to controls. These findings were confirmed by Western blot analysis. Furthermore, both proteins were localized to astrocytes and in epileptic brain were located within the cerebral hyaline astrocytic inclusions, suggesting a potential role in the generation of this pathologic feature of early onset epilepsy with cerebral hyaline astrocytic inclusions. [ABSTRACT FROM AUTHOR]

Ependymomas are the third most common pediatric brain tumor with an overall survival of ∼50%. Recently, we showed that telomerase [human telomerase reverse transcriptase (hTERT)] expression is a predictor of poor outcome in pediatric ependymoma. Thus, we hypothesized that ependymomas with functional telomerase may behave more aggressively and that these patients may benefit from anti-telomerase therapy. To address our hypothesis, we investigated the effect of telomerase inhibition on primary ependymoma cells harvested at the time of surgery, as no animal models or established cell lines are readily available for this tumor. The cells were characterized for glial fibrillary acidic protein (GFAP) and hTERT expression, initial telomere length and telomerase activity. They were then subjected to telomerase inhibition (MST-312, 1 µM) and tested for effects on cell viability (MTT assay), proliferation (MIB-1), apoptosis (cleaved caspase 3) and DNA damage (γH2AX). After 72 h of telomerase inhibition, primary ependymoma cells showed a significant decrease in cell number ( P < 0.001), accompanied by increased DNA damage (γH2AX expression) ( P < 0.01) and decreased proliferative index (MIB-1) ( P < 0.01). Half showed an increase in apoptosis (cleaved caspase 3). These data suggest that telomerase inhibition may be an effective adjuvant therapy in pediatric ependymoma, potentially inducing tumor growth arrest in the short term, independent of telomere shortening. [ABSTRACT FROM AUTHOR]

Congenital central nervous system (CNS) tumors are uncommon, accounting for 1% of all childhood brain tumors. They present clinically either at birth or within the first 3 months. Glioblastoma (GBM) only rarely occurs congenitally and has not been fully characterized. We examined clinicopathologic features and genetic alterations of six congenital GBMs. Tumors were seen by neuroimaging as large, complex cerebral hemispheric masses. All showed classic GBM histopathology, including diffuse infiltration, dense cellularity, GFAP-positivity, high mitotic activity, endothelial proliferation and pseudopalisading necrosis. Neurosurgical procedures and adjuvant therapies varied. Survivals ranged from 4 days to 7.5 years; two of the three long-term survivors received chemotherapy, whereas the three short-term survivors did not. Paraffin-embedded tissue sections were used for FISH analysis of EGFR, chromosomes 9p21 ( p16/CDKN2A) and 10q ( PTEN/DMBT1); sequencing of PTEN and TP53; and immunohistochemistry for EGFR and p53. We uncovered 10q deletions in two cases. No EGFR amplifications, 9p21 deletions, or mutations of TP53 or PTEN were noted; however, nuclear p53 immunoreactivity was strong in 5/6 cases. Tumors were either minimally immunoreactive (n = 3) or negative (n = 3) for EGFR. We conclude that congenital GBMs show highly variable survivals. They are genetically distinct from their adult counterparts and show a low frequency of known genetic alterations. Nonetheless, the strong nuclear expression of p53 in these and other pediatric GBMs could indicate that p53 dysregulation is important to tumorigenesis. [ABSTRACT FROM AUTHOR]

Background: Posterior fossa ependymoma (PFE) comprises 2 groups, PF group A (PFA) and PF group B (PFB), with stark differences in outcome. However, to the authors' knowledge, the long-term outcomes of PFA ependymoma have not been described fully. The objective of the current study was to identify predictors of survival and neurocognitive outcome in a large consecutive cohort of subgrouped patients with PFE over 30 years.Methods: Demographic, survival, and neurocognitive data were collected from consecutive patients diagnosed with PFE from 1985 through 2014 at the Hospital for Sick Children in Toronto, Ontario, Canada. Subgroup was assigned using genome-wide methylation array and/or immunoreactivity to histone H3 K27 trimethylation (H3K27me3).Results: A total of 72 PFE cases were identified, 89% of which were PFA. There were no disease recurrences noted among patients with PFB. The 10-year progression-free survival rate for all patients with PFA was poor at 37.1% (95% confidence interval, 25.9%-53.1%). Analysis of consecutive 10-year epochs revealed significant improvements in progression-free survival and/or overall survival over time. This pertains to the increase in the rate of gross (macroscopic) total resection from 35% to 77% and the use of upfront radiotherapy increasing from 65% to 96% over the observed period and confirmed in a multivariable model. Using a mixed linear model, analysis of longitudinal neuropsychological outcomes restricted to patients with PFA who were treated with focal irradiation demonstrated significant continuous declines in the full-scale intelligence quotient over time with upfront conformal radiotherapy, even when correcting for hydrocephalus, number of surgeries, and age at diagnosis (-1.33 ± 0.42 points/year; P = .0042).Conclusions: Data from a molecularly informed large cohort of patients with PFE clearly indicate improved survival over time, related to more aggressive surgery and upfront radiotherapy. However, to the best of the authors' knowledge, the current study is the first, in a subgrouped cohort, to demonstrate that this approach results in reduced neurocognitive outcomes over time. [ABSTRACT FROM AUTHOR]