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Background Primary intratumoral hemorrhage as a presenting sign is rare in children with medulloblastomas but may result in severe complications. Given the distinct properties of molecular medulloblastoma subgroups, the impact on neurosurgical practice has still to be defined. Objective To investigate both clinical and radiological presentation of intratumoral hemorrhage in medulloblastoma patients in the context of molecular subgroups. Methods Data of all consecutive medulloblastoma patients treated at our institution between 1993 and 2018 (n = 104) were retrospectively reviewed in respect of clinical and radiological presentation as well as molecular subgroups. For cases with available tumor tissue (n = 86), subgroups were assigned by either 450 K methylation array or immunohistochemistry and CTNNB1 sequencing. Available imaging at diagnosis (n = 62) was reviewed by an experienced neuroradiologist. Results Within the entire cohort, 4 patients (4%) presented with massive spontaneous hemorrhage. Although no patient died as a direct consequence of hemorrhage, all suffered from serious sequelae. Moreover, 3 additional patients displayed radiological evidence of significant hemorrhage. Interestingly, all 7 cases belonged to the wingless (WNT) subgroup (n = 13), resulting in intratumoral hemorrhage in 54% (7/13) of pediatric WNT medulloblastomas. In contrast, significant hemorrhage was absent in all other molecular subgroups. Conclusion Our results suggest that a substantial proportion of pediatric WNT medulloblastomas display significant intratumoral hemorrhage at the time of diagnosis. Consequently, the presence of significant hemorrhage in fourth ventricle childhood tumors is suggestive of WNT medulloblastoma and should lead to a less aggressive attempt for total resection in this prognostically favorable tumor type.

Summary Medulloblastoma is a malignant childhood cerebellar tumour comprised of distinct molecular subgroups. Whereas genomic characteristics of these subgroups are well defined, the extent to which cellular diversity underlies their divergent biology and clinical behaviour remains largely unexplored. We used single-cell transcriptomics to investigate intra- and inter-tumoural heterogeneity in twenty-five medulloblastomas spanning all molecular subgroups. WNT, SHH, and Group 3 tumours comprised subgroup-specific undifferentiated and differentiated neuronal-like malignant populations, whereas Group 4 tumours were exclusively comprised of differentiated neuronal-like neoplastic cells. SHH tumours closely resembled granule neurons of varying differentiation states that correlated with patient age. Group 3 and Group 4 tumours exhibited a developmental trajectory from primitive progenitor-like to more mature neuronal-like cells, whose relative proportions distinguished these subgroups. Cross-species transcriptomics defined distinct glutamatergic populations as putative cells-of-origin for SHH and Group 4 subtypes. Collectively, these data provide novel insights into the cellular and developmental states underlying subtype-specific medulloblastoma biology.

BACKGROUND: Prognosis of patients with recurrent atypical teratoid rhabdoid tumor (ATRT) is dismal despite intensive therapy including high-dose chemotherapy with stem cell rescue. An evolving alternative approach to conventional chemotherapy is to target neovascularisation by interfering with tumor angiogenesis at various levels. We report on 12 patients with recurrent ATRT treated with an antiangiogenic combination therapy. Patients and Methods: From 03/2008 to 02/2018, 12 patients were diagnosed with recurrent ATRT (6 first, 6 multiple recurrences), three had germ line mutations. Treatment consisted of an antiangiogenic multidrug-regime including IV bevacizumab, oral thalidomide, celecoxib, fenofibrate, and etoposide alternating with cyclophosphamide, and augmented with intraventricular therapy (etoposide and liposomal cytarabine) with or without focal radiotherapy. Median age at start of antiangiogenic therapy was 3 (1–12) years. RESULTS: As of 05/2018, 6/12 patients are alive and in CR for 123, 90, 45, 9, 6 and 3 months after start of antiangiogenic therapy, the first three off therapy. One patient died of another cause 50 months after her recurrence in CR and without evidence of tumor at autopsy. OS for the whole cohort was 47.7 ± 16.6% at 3 years and 31.8 ± 17.1% at 5-years with a median OS of 22.8 months (KI 0.0–66.8). Therapy was generally well tolerated and toxicities were manageable. CONCLUSION: The proposed antiangiogenic regimen is currently being evaluated for medulloblastomas in an international phase II protocol (MEMMAT; ClinicalTrials.gov Identifier: NCT01356290). The same approach seems to be also efficacious in recurrent ATRTs and warrants further evaluation.

The HERBY trial was a phase-II open-label, randomised, multicentre trial evaluating bevacizumab in addition to temozolomide/radiotherapy in patients with newly-diagnosed non-brainstem high-grade glioma between the ages of 3-18 years. We collected specimens from 89/113 patients consenting to translational research, and carried out comprehensive molecular analysis integrated with pathology, radiology and immune profiling. 7/89 patients harboured H3F3A_G34R/V mutations (diffusely infiltrative with predominant deep left temporoparietal involvement), whilst 24/89 harboured H3F3A_K27M, both conferring a worse outcome. Of the latter, two patients had distinct, separate lesions in the thalamus and hypothalamus, whilst the remaining had symmetrical central thalamic and midbrain localization. Four older patients had tumours harbouring IDH1 mutations, whilst three younger patients had tumours which by methylation profiling resembled low grade lesions; both of these hemispheric subgroups had a significantly longer survival. Hypermutator tumours (driven by mismatch repair deficiency and somatic POLE / POLD1 mutations) and those biologically resembling pleomorphic xanthoastrocytoma (PXA-like, driven by BRAF_V600E or NF1 mutation) had an elevated immune response in the form of CD8-positive tumour infiltrating lymphocytes (p=0.0018), and had longer overall survival in the bevacizumab arm (p=0.0489). Histone H3 subgroups (hemispheric G34R/V and midline K27M) had a worse outcome and were immune cold. Although the experimental arm did not improve survival across the whole cohort, we identify disease subgroups with MAPK activation to harbour an enhanced immune response and derive benefit from the addition of bevacizumab to standard temozolomide/radiotherapy.

Prognostic risk factors in medulloblastomas currently comprise extent of resection, M-staging at diagnosis, histopathological subtype and genetic aberrations (MYC/N status, CTNNB1 mutation). The majority of medulloblastomas with WNT activation (WNT-MB) are characterized by CTNNB1 mutation and associated with a particular good prognosis in children up to 16 years of age. Tumor recurrence and death of disease are exceptional in children having WNT-MB, therefore they are considered as low risk tumors and treated with a decreased chemotherapy protocol in the European PNET5 therapy trial. We report a female patient from Georgia who presented at the age of 9 years with a cerebellar midline tumor. The tumor was completely resected and diagnosed as medulloblastoma. She was treated with RTX and CTX. 5 years after diagnosis a local recurrence occurred and a reoperation was performed. Histopathology revealed a classic medulloblastoma, a CTNNB1 mutation was detected by Sanger sequencing and WNT subgroup confirmed by methylation array. Re-evaluation of the primary tumor confirmed the diagnosis of a classic medulloblastoma, however no CTNNB1 mutation could be detected. Despite gross total resection of the recurrence followed by antiangiogenic metronomic treatment the tumor progressed after one year, and the patient succumbed to her disease. Postmortem analysis revealed a highly anaplastic medulloblastoma with focal myogenic differentiation (medullomyoblastoma) and CTNNB1 mutation. In conclusion, the absence of a detectable CTNNB1 mutation in the primary tumor could indicate its presence only in a small subclone and shows that a WNT-MB with a classic subtype may occasionally evolve into a highly anaplastic MB.

CNS-PNET is no longer regarded a single disease but encompassed many distinct molecular entities. After removal of the term from the 2016 WHO classification of CNS tumours, diagnostic and therapeutic uncertainty remains. Through a world-wide collaboration, tumour samples from patients with the “historic” diagnosis of CNS-PNET were re-evaluated by DNA methylation profiling (n=405) and blinded neuropathological panel review (n=256). Clinical data on treatment and outcome were pooled with data on previously published patients. The given numbers represent preliminary data of the ongoing project. The re-evaluation by DNA methylation identified many distinct entities as expected, including high grade glioma (HGG, n=70), embryonal tumors with multilayered rosettes (ETMR, n=57) and CNS-neuroblastoma with FOXR2 alteration (CNS-NB-FOXR2, n=42) as the most frequent molecular diagnostic categories. Poor clinical outcome was confirmed for patients with HGG (5y-PFS 12%/5y-OS 12%, n=24), and ETMR (5y-PFS 12%/5y-OS 18%, n=62), while most patients with CNS-NB-FOXR2 survived (5y-PFS 52%/5y-OS 96%, n=31). Seven of 12 relapses/progressions of CNS-NB-FOXR2 occurred in radiotherapy-naïve patients. Classification into other newly described and less common entities included HGNET-MN1 (n=19), HGNET-BCOR (n=11), and EFT-CIC (n=13). Independent neuropathological review demonstrated that samples of these entities presented as non-embryonal tumours. Furthermore, marked clinical differences exist (HGNET-MN1: 5y-PFS 25%/5y-OS 95%, n=22; HGNET-BCOR: 5y-PFS 0%/5y-OS 44%, n=16; CNS-EFT-CIC: 5y-PFS 40%/5y-OS 60%, n=10). Our results show that implementation of DNA methylation profiling together with histopathological analysis will improve prospective diagnostic accuracy and facilitates the retrospective outcome analysis of treatment protocols used for this variety of biologically distinct entities.

Atypical teratoid/rhabdoid tumor (AT/RT) is an aggressive malignancy of infancy and early childhood representing the most common CNS tumor in children below the age of one year. AT/RTs harbour germline or somatic mutations in SMARCB1 or SMARCA4 while other recurrent genetic alterations are lacking. Though survival rates have slightly improved over the last years, prognosis remains poor, especially in the case of relapse. Our project aims at understanding molecular events contributing to relapse in AT/RT. To this end, histopathological and molecular features (DNA methylation array and whole exome sequencing) of 21 pairs of primary and relapsed AT/RTs were investigated. On histopathological examination, relapsed AT/RTs showed loss of architecture and significantly increased proliferation as compared to primary tumors. Although molecular subgroups did not change at recurrence, global methylation analysis of matched primary and recurrent tumor samples demonstrated an enrichment of differentially methylated areas at transcribed regions and promoters and distinct changes in trimethylation at H3K27 in a fraction of relapsed cases. CNV profiling revealed recurrent gains at multiple regions, while losses preferentially affected histone genes at chromosome 6. Finally, whole exome sequencing discovered a number of mutations affecting more than 3 relapse samples, but not the respective primary lesions. Our findings may contribute to improve the understanding of biological changes leading to enhanced aggressiveness of relapsed AT/RTs and provide a basis for further functional analyses.

OBJECTIVE: To evaluate the frequency and potential predicting factors for CSF disturbances in a series of patients operated through a transcallosal approach. METHODS: We retrospectively reviewed the medical charts of all patients operated at our institution via a transcallosal approach between January 2002 and December 2016. The following radiological parameters were assessed on pre- and multiple postoperative MR/CT images: ventricular size, as well as subdural space and interhemispheric fissure width. Statistical analyses were performed to identify clinical and radiological predicting factors for shunt dependent hydrocephalus within three months after surgery. RESULTS: We identified 74 patients (female n=40, male n=34; median age 17.6yrs, range from 6 mos - 76 yrs). An EVD was placed preoperatively in 18 patients (24.3%). Histology revealed a colloid cyst in 15 (20.3%), pilocytic astrocytoma in 14 (18.9%), diffuse astrocytoma WHO II in 5 (6.8%), diffuse astrocytoma WHO III+IV in 7 (9.5%), subependymal giant cell astrocytoma in 5 (6.8%), craniopharyngioma in 5 (6.8%) and other in 23 (31.0%). After a median time of 24 days (range from 10 days - 3 mos) since transcallosal resection implantation of a VP-shunt was necessary in 9 patients (12.2%) and a subduro-peritoneal shunt in 5 (6.6%). The mean age at shunt implantation was 14.3 yrs. The necessity for postoperative shunt implantation was significantly associated with younger age. CONCLUSION: The incidence of early shunt dependent hydrocephalus after transcallosal resection is high (18.8%), especially in younger children. The reason for shunt dependency is multifactorial.

Regenerative processes that counteract perifascicular muscle atrophy and capillary loss in juvenile dermatomyositis (JDM) are not well characterized. We aimed to analyze the pattern of myo-regeneration in relation to vascular damage and repair in muscle specimens from JDM patients. Myogenic regulatory factors that are sequentially expressed during myogenesis were studied by immunohistochemistry. Capillary density, numbers of CD34+ endothelial progenitor cells within the endomysium and molecules implicated in angiogenesis were evaluated by double-immunofluorescence techniques. Myogenic regulatory factors were significantly up-regulated in JDM muscle exhibiting a different pattern in early and advanced lesions. In early lesions Pax7+ satellite cells and both MyoD+ and Myogenin+ myogenic cells were moderately increased. In lesions with advanced perifascicular atrophy Pax7+ satellite cells were numerous, but absence of MyoD+ in the context of increased Myogenin+ expression suggested a dysregulation of the myogenic regenerative pathway. The overall capillary density in JDM was decreased, but regions of capillary loss in advanced lesions alternated with focal increase of hyperplastic endothelial cells in early lesions. Up-regulation of endoglin in hyperplastic endothelial cells in conjunction with overexpression of TGF-β1 and VEGF suggested activation of neovascularization. Conversely, CD34+ endothelial progenitor cells were not increased arguing against relevant contribution to vascular repair. Our results demonstrate substantial induction of myogenesis in JDM. While the early phase of myogenesis appears to be associated with endothelial cell activation, an altered expression of MRFs in perifascicular regions with capillary depletion suggests an impairment of myogenic differentiation that may contribute to perifascicular muscle fiber atrophy in JDM.

Cancer cells often express differentiation programs unrelated to their tissue of origin, although the contribution of these aberrant phenotypes to malignancy is poorly understood. An aggressive subgroup of medulloblastoma, a malignant pediatric brain tumor of the cerebellum, expresses a photoreceptor differentiation program normally expressed in the retina. We establish that two photoreceptor-specific transcription factors, NRL and CRX, are master regulators of this program and are required for tumor maintenance in this subgroup. Beyond photoreceptor lineage genes, we identify BCL-XL as a key transcriptional target of NRL and provide evidence substantiating anti-BCL therapy as a rational treatment opportunity for select MB patients. Our results highlight the utility of studying aberrant differentiation programs in cancer and their potential as selective therapeutic vulnerabilities.

The cellular composition of H3K27M gliomas Diffuse midline gliomas with histone H3 lysine27-to-methionine mutations (H3K27M-glioma) are an aggressive type of childhood cancer with few options for treatment. Filbin et al. used a single-cell sequencing approach to study the oncogenic programs, genetics, and cellular hierarchies of H3K27M-glioma. Tumors were mainly composed of cells resembling oligodendrocyte precursor cells, whereas differentiated malignant cells were a smaller fraction. In comparison with other gliomas, these cancers had distinct oncogenic programs and stem cell–like profiles that contributed to their stable tumor-propagating potential. The analysis also identified a lineage-specific marker that may be useful in developing therapies. Science , this issue p. 331

Aims Wnt activation in medulloblastomas is associated with good outcome. Upfront testing and risk-adapted stratification of patients will be done in future clinical studies. In a cohort of 186 paediatric medulloblastomas our aim was to identify the optimal methods in standard clinical practice to detect this subgroup. Methods Nuclear accumulation of β-catenin was analysed by immunohistochemistry (IHC). DNA of FFPE tissue was amplified by PCR for single-strand conformation polymorphism analysis and direct sequencing of CTNNB1 exon 3. Copy number of chromosome 6 was analysed by multiplex ligation-dependent probe amplification and molecular inversion profiling. Results Different automated immunostaining systems showed similar results. Twenty-one of 186 samples had nuclear accumulation in ≥5% of cells, 17 samples showed

While human tumors are shaped by the genetic evolution of cancer cells, evidence also suggests that they display superimposed hierarchies reminiscent of normal development. Yet, relating the genetic and hierarchical models of cancer organization has been limited by technical challenges. Here, studying H3 K27M-mutant diffuse midline gliomas we profiled thousands of single cells from fresh tumors by RNA-seq and reconstructed the genetic and epigenetic cellular architecture of tumors in patients. We identified a subset of cancer cells that are differentiated along specialized glial programs while a distinct subset expresses oligodendrocyte precursor expression programs. By identifying distinct genetic clones, we show that these cellular architectures evolve during the progression of the tumors, suggesting that developmental programs and genetic influences coordinately determine tumor architecture. These results provide unprecedented insight into the cellular composition of midline brain tumors at single-cell resolution and may help harmonize the cancer stem cell and the genetic models of cancer, with critical implications for disease management.

Introduction: Medulloblastoma is the most common malignant brain tumor in children, but accounts only for 1% of all CNS tumors in adults. Medulloblastoma comprises histopathologically classic, nodular/desmoplastic and large cell/anaplastic subtypes, and four molecular subgroups including WNT, SHH, group 3 and group 4 tumors. Previous studies have shown that histopathological subtypes and molecular subgroups differ between adults and children. Whereas SHH-nodular/desmoplastic tumors are rare in children between 4 and 16 years, they represent the most frequent subtype in adults. Material and Methods: 35 medulloblastomas of adult patients (aged 21 to 76 years, in median 33.5 years) were included in the study. 25 patients were male, 10 female. FFPE tumor tissue was analyzed using a reticulin staining and antibodies against synaptophysin, GFAP, Ki67, β-catenin, GAB1, YAP1, and p53. Tumors were classified according to the recent WHO classification of CNS tumors. Survival data were available in 23 patients. Results: 26 (74.3%) tumors were classified as SHH, 7 (20%) as non-WNT/non-SHH, and 2 (5.7%) as WNT medulloblastomas. All non-SHH tumors displayed a classic histopathological subtype, and all except 2 SHH tumors were of the desmoplastic/nodular histopathological subtype. These 2 tumors showed a classic morphology, but the recurrence of one tumor had characteristic desmoplastic/nodular features. In all patients, 5 year overall survival was 85.4%. Interestingly, the oldest patient (76 years at diagnosis) who had a SHH tumor is still alive 10 years after diagnosis. Conclusion: We confirm that SHH tumors represent the most common tumors in adult patients (>21 years) and show that long-term survival is feasible in very old patients.

Genome-wide molecular approaches have substantially elucidated molecular alterations and pathways involved in the oncogenesis of brain tumors. In gliomas, several molecular biomarkers including IDH mutation, 1p/19q co-deletion, and MGMT promotor methylation status have been introduced into neuropathological practice. Recently, mutations of the ATRX gene have been found in various subtypes and grades of gliomas and were shown to refine the prognosis of malignant gliomas in combination with IDH and 1p/19q status. Mutations of ATRX are associated with loss of nuclear ATRX protein expression, detectable by a commercially available antibody, thus turning ATRX into a promising prognostic candidate biomarker in the routine neuropathological setting.

Central nervous system high-grade neuroepithelial tumor with BCL6-corepressor alteration (CNS HGNET-BCOR) is a recently discovered molecular brain tumor entity characterized by genomic alterations of BCOR, a central component of a non-canonical polycomb repressive complex. However, the underlying oncogenic mechanisms and their consequences for tumor-specific anti-cancer therapy remain widely enigmatic. We systematically analyzed genomics, transcriptomics, and drug-sensitivity patterns in three tumor-derived models (two cell-lines, one primary cell-culture) from three consecutive intracranial CNS HGNET-BCOR metastases of one patient. All models harbored a unique frameshift mutation within BCOR resulting in a truncated protein lacking functionally important c-terminal protein domains. Re-expression of BCOR wild-type in our CNS HGNET-BCOR cell-models resulted in decreased cell proliferation and increased apoptosis. Interestingly, genes downregulated upon re-expression of BCOR wild-type were also derepressed in CNS HGNET-BCOR tumor tissues harboring BCOR-alterations different from our case (e.g. internal tandem duplication in BCOR). Via comparison with a chromatin immunoprecipitation DNA-sequencing dataset, we determined that a significant proportion of the corresponding gene promoters are occupied by BCOR in BCOR wild-type cancer cells. An additional drug-screen demonstrated hypersensitivity of CNS HGNET-BCOR cells against histone deacetylase inhibitors and histone methyltransferase inhibitors. Matching of drug sensitivity patterns to upregulated target-genes determined bortezomib, dasatinib, and crizotinib as promising tumor-specific therapeutics against CNS HGNET-BCOR. Taken together, our results suggest that dysfunction of BCOR-mediated gene repression determines the oncogenic behavior and transcriptomic profile of CNS HGNET-BCOR. Moreover, we provide preliminary results for potential pharmacological interventions against this aggressive tumor type.

No Abstract available.

Background: Unlike malignant primary central nervous system (CNS) tumours outcome data on non-malignant CNS tumours are scarce. For patients diagnosed from 1996 to 2002 5-year relative survival of only 85.0% has been reported. We investigated this rate in a contemporary patient cohort to update information on survival. Methods: We followed a cohort of 3983 cases within the Austrian Brain Tumour Registry. All patients were newly diagnosed from 2005 to 2010 with a histologically confirmed non-malignant CNS tumour. Vital status, cause of death, and population life tables were obtained by 31 December 2011 to calculate relative survival. Results: Overall 5-year relative survival was 96.1% (95% CI 95.1–97.1%), being significantly lower in tumours of borderline (90.2%, 87.2–92.7%) than benign behaviour (97.4%, 96.3–98.3%). Benign tumour survival ranged from 86.8 for neurofibroma to 99.7% for Schwannoma; for borderline tumours survival rates varied from 83.2 for haemangiopericytoma to 98.4% for myxopapillary ependymoma. Cause of death was directly attributed to the CNS tumour in 39.6%, followed by other cancer (20.4%) and cardiovascular disease (15.8%). Conclusion: The overall excess mortality in patients with non-malignant CNS tumours is 5.5%, indicating a significant improvement in survival over the last decade. Still, the remaining adverse impact on survival underpins the importance of systematic registration of these tumours.

Neurodegenerative diseases are characterised by neuronal loss and cerebral deposition of proteins with altered physicochemical properties. The major proteins are amyloid-β (Aβ), tau, α-synuclein, and TDP-43. Although neuropathological studies on elderly individuals have emphasised the importance of mixed pathologies, there have been few observations on the full spectrum of proteinopathies in the ageing brain. During a community-based study we performed comprehensive mapping of neurodegeneration-related proteins and vascular pathology in the brains of 233 individuals (age at death 77–87; 73 examined clinically in detail). While all brains (from individuals with and without dementia) showed some degree of neurofibrillary degeneration, Aβ deposits were observed only in 160 (68.7 %). Further pathologies included α-synucleinopathies (24.9 %), non-Alzheimer tauopathies (23.2 %; including novel forms), TDP-43 proteinopathy (13.3 %), vascular lesions (48.9 %), and others (15.1 %; inflammation, metabolic encephalopathy, and tumours). TDP-43 proteinopathy correlated with hippocampal sclerosis (p

The revised WHO classification of tumors of the CNS 2016 has introduced the concept of the integrated diagnosis. The definition of medulloblastoma entities now requires a combination of the traditional histological information with additional molecular/genetic features. For definition of the histopathological component of the medulloblastoma diagnosis, the tumors should be assigned to one of the four entities classic, desmoplastic/nodular (DNMB), extensive nodular (MBEN), or large cell/anaplastic (LC/A) medulloblastoma. The genetically defined component comprises the four entities WNT-activated, SHH-activated and TP53 wildtype, SHH-activated and TP53 mutant, or non-WNT/non-SHH medulloblastoma. Robust and validated methods are available to allow a precise diagnosis of these medulloblastoma entities according to the updated WHO classification, and for differential diagnostic purposes. A combination of immunohistochemical markers including β-catenin, Yap1, p75-NGFR, Otx2, and p53, in combination with targeted sequencing and copy number assessment such as FISH analysis for MYC genes allows a precise assignment of patients for risk-adapted stratification. It also allows comparison to results of study cohorts in the past and provides a robust basis for further treatment refinement. .

Intracranial classic (WHO grade II) and anaplastic (WHO grade III) ependymomas are among the most common tumors in pediatric patients and have due to frequent recurrences and late relapses a relatively poor outcome. The impact of histopathological grading on patient outcome is controversial and therefore, molecular prognostic and predictive markers are needed to improve patient outcome. To date, the most promising candidate marker is chromosome 1q gain, which has been associated in independent studies with adverse outcome. Furthermore, gene expression and methylation profiles revealed distinct molecular subgroups in the supratentorial and posterior fossa (PF) compartment and Laminin alpha-2 (LAMA2) and Neural Epidermal Growth Factor Like-2 (NELL2) were suggested as surrogate markers for the two PF subgroups PF-EPN-A and PF-EPN-B. PF-EPN-A tumors were also characterized by tenascin-C (TNC) expression and tenascin-C has been suggested as candidate gene on 9q, involved in tumor progression. Therefore, we have analyzed the status of chromosome 1q, TNC, LAMA2, and NELL2 expression in a series of pediatric PF ependymomas in terms of their frequency, associations among themselves, and clinical parameters, as well as their prognostic impact. We confirm the negative prognostic impact of 1q gain and TNC expression and could classify PF ependymomas by these two markers into three molecular subgroups. Tumors with combined 1q gain and TNC expression had the poorest, tumors without 1q gain and TNC expression had a favorable and TNC positive 1q non-gained cases had an intermediate outcome. We found also differences in age and tumor grade in the three subgroups and thus, provide evidence that PF pediatric ependymomas can be divided by chromosome 1q status and TNC expression in three molecular subgroups with distinct clinico-pathological features. These analyses require only few amounts of tumor tissue, are broadly available in the routine clinical neuropathological setting and thus, could be used in further therapy trials to optimize treatment of ependymoma patients.

PNR-32. UPDATE OF DIAGNOSTICS OF PRIMITIVE NEUROECTODERMAL TUMOURS OF THE CNS NEUROPATHOLOGICAL RE-EVALUATION OF 99 CASES Torsten Pietsch1, Dominique Figarella-Branger2, Cynthia Hawkins3, Felice Giangaspero4, Thomas S. Jacques5, Marco Gessi1, Peter Burger6, Christine Haberler7, and for the Internatonal CNS-PNET working group1; University of Bonn, Bonn, Germany; University of Marseille, Marseille, France; The Hospital for Sick Children, Toronto, Canada; University of Rome, Rome, Italy; University of London, London, UK; Johns Hopkins University, Baltimore, USA; University of Vienna, Vienna, Austria Recent analysis of tumours historically diagnosed as CNS-PNET by epigenetic profiling has led to the hypothesis that such cases may represent morphological mimics of CNS-PNET but can be largely assigned to other tumour entities, and that CNS-PNET are frequently misclassified by neuropathological diagnostics. As part of an international effort to collect and re-analyze CNS-PNET, 99 tumours diagnosed as CNS-PNET or pineoblastoma in the last 2 decades in 9 European countries were reviewed according to today’s standards of neuropathological diagnostics. 46% of cases were confirmed as CNS-PNET; of these, 68% were diagnosed as ETMR (including ependymoblastoma/ medulloepithelioma), and 32% as other CNS-PNET (CNS-PNET, NOS (n 1⁄4 11), CNSneuroblastoma (n 1⁄4 3) and CNS-ganglioneuroblastoma (n 1⁄4 2)). 54% of tumours were defined as other entities includingpineal parenchymal tumours (pineoblastoma/PPID; n 1⁄4 12), (anaplastic) ependymomas (n 1⁄4 7), PXA (n 1⁄4 2), diffuse high-grade gliomas (n 1⁄4 15), ATRT (n 1⁄4 3), mesenchymal tumours /sarcomas (n 1⁄4 7), germ cell tumour (n 1⁄4 1) and medulloblastoma (n 1⁄4 1), and 5 tumours were not classifiable, mostly because of insufficient biopsy material. A marker panel was defined for an optimized approach for the assessment of CNS-PNETs and tumours mimicking these neoplasms in routine neuropathological diagnostic workup. This study shows that (1) today’s diagnostic repertoire allows assignment of CNS-PNET cases, and (2) retrospective cohorts treated in neuro-oncological studies have to be re-analyzed to allow meaningful conclusions on effectiveness of specific treatment modalities. This cohort will be used to cross-validate assignment to tumour entities by epigenetic profiling and the associated clinical datawill be re-analyzed inan internationalmeta-analysis. Supported by the German Children’s Cancer Foundation. Neuro-Oncology 18:iii7–iii15, 2016. doi:10.1093/neuonc/now067.27 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Purpose: Medulloblastoma is the most common malignant brain tumor in children. Despite recent improvements, the molecular mechanisms driving medulloblastoma are not fully understood and further elucidation could provide cues to improve outcome prediction and therapeutic approaches. Experimental Design: Here, we conducted a meta-analysis of mouse and human medulloblastoma gene expression data sets, to identify potential medulloblastoma tumor suppressor genes. Results: We identified DAB2IP, a member of the RAS-GTPase–activating protein family (RAS GAP), and showed that DAB2IP expression is repressed in medulloblastoma by EZH2-induced trimethylation. Moreover, we observed that reduced DAB2IP expression correlates significantly with a poor overall survival of patients with medulloblastoma, independent of metastatic stage. Finally, we showed that ectopic DAB2IP expression enhances stress-induced apoptosis in medulloblastoma cells and that reduced expression of DAB2IP in medulloblastoma cells conveys resistance to irradiation-induced cell death. Conclusion: These results suggest that repression of DAB2IP may at least partly protect medulloblastoma cells from apoptotic cell death. Moreover, DAB2IP may represent a molecular marker to distinguish patients with medulloblastoma at high risk from those with a longer survival prognosis. Clin Cancer Res; 18(15); 4048–58. ©2012 AACR.

Background Median survival time of recurrent embryonal brain tumors is short regardless of salvage chemotherapy used. An evolving alternative approach to conventional chemotherapy is to target neovascularization by interfering with tumor angiogenesis at various levels. Procedure From November 2006 to December 2010, 16 patients (median age: 9 years) with recurrent (9 first, 7 multiple) embryonal brain tumors were treated with an antiangiogenic multidrug combination regimen (bevacizumab, thalidomide, celecoxib, fenofibrate, etoposide, and cyclophophamide) and additional intraventricular therapy (etoposide and liposomal cytarabine). Results At a median of 33 months, 10/16 patients are alive. 4/4 patients with CNS primitive neuroectodermal tumors (CNS PNET) and 1/7 patients with medulloblastoma (MB) died of tumor progression during the first year. Another patient with MB died of an accident after 23 months, the remaining five patients with MB are alive for 12, 33, 33, 37, and 58 months. For the seven patients with MB, both overall survival (OS) and event free survival (EFS) after 6 months was 100%, after 12 months 85.7 ± 13%, and after 24 months 68.6 ± 19%. In contrast, for patients with CNS PNET, both OS and EFS after 6 months was 75.0 ± 22% and 0.0% and all patients had died by 12 months. Low-dose oral etoposide and cyclophosphamide was reduced after a median of 2 months and discontinued after a median of 11 months. Toxicities were manageable and therapy was generally well tolerated. Conclusion Our results suggest that the chosen antiangiogenic drug combination is particularly beneficial for patients with MB and warrants further investigation. Pediatr Blood Cancer 2012;59:511–517. © 2011 Wiley Periodicals, Inc.

Pediatric medulloblastoma is considered a highly heterogeneous disease and a new strategy of risk stratification to optimize therapeutic outcomes is required. We aimed to investigate a new risk-stratification approach based on expression profiles of medulloblastoma cohorts. We analyzed gene expression profiles of 30 primary medulloblastomas and detected strong evidence that poor survival outcome was significantly associated with mRNA expression profiles of 17p loss. However, it was not supported in independent cohorts from previously published data (n = 100). We speculated that this discrepancy might come from complex conditions of two important prognostic determinants: loss of tumor suppressors (chromosome 17p) and high expression of oncogenes c-myc (MYCC) or N-myc (MYCN). When patients were stratified into 5 or 7 subgroups based on simultaneous consideration of these 2 factors while defining the Wnt group as independent, obviously different survival expectancies were detected between the subgroups. For instance, predicted 5-year survival probabilities ranged from 19% to 81% in the 5 subgroups. We also found that age became a significant prognostic marker after adjusting for 17p, MYCC, and MYCN status. Diminished survival in age

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a recently recognized, rare embryonal CNS tumor, which predominantly occurs in young children and is associated with a highly aggressive disease course [1–3, 5–8, 13, 14, 18, 19, 23]. The histopathological diagnosis of ETANTR is based on the presence of primitive neuroectodermal tumor cells forming distinct multilayered ‘ependymoblastic’ rosettes and characteristic neuropil islands. Recently, genome-wide analyses have revealed a novel amplification at 19q13.42 [16, 19], which is meanwhile considered the genetic hallmark of ETANTR [13, 16]. The characteristic clinical, morphological, and genetic features support the concept of a distinct CNS PNET variant and suggest its introduction to the WHO classification of Tumors of the Central Nervous System [17]. As the amplification at 19q13.42 has also been found in the vast majority of ependymoblastomas analyzed to date [13, 16], the common genetic background suggests the fusion of these two tumor types to a single entity. Herein, we report for the first time the evolution of morphological features and genetic aberrations during the disease course in a patient with ETANTR. A 33-monthold girl presented with a 6-month history of episodic headaches, increased head circumference and mild gait disturbance. Magnetic resonance (MR) imaging showed a 9.6 9 8.6 9 11.7 cm left parieto-occipital, space-occupying, partly cystic lesion displaying T1-weighted hypoto isointense signals (Fig. 1a) with cerebrospinal fluid-intense cysts on FLAIR sequence (Fig. 1b), and marked choline/ creatine increase as a sign of cell proliferation on single voxel spectroscopy (Fig. 1c). Near-total surgical resection was performed. Histopathology revealed a primitive neuroectodermal tumor with highly cellular areas. Furthermore, hypocellular neuropil islands and multilayered rosettes were

The codeletion of chromosomal arms 1p 19q is a characteristic and early genetic event in oligodendroglial tumors, that is associated with a better prognosis and enhanced response to therapy. Over the last years, the increasing clinical demand to determine the lp 19q status has led to the implementation of its testing in many neuropathology laboratories. Several different methods for 1p 19q testing are available: PCR-based loss of heterozygosity analysis, multiplex ligation-dependent probe amplification, array comparative genomic hybridization, and fluorescence in situ hybridization (FISH). Herein, we focus and critically discuss the latter method because a detailed description of procedures and protocols for FISH-based lp 19q testing in practice is lacking. We present a practical approach to the FISH-based assessment of the 1p 19q status in oligodendroglial tumors, from commonly used locus-specific probes and technical protocols to the neuropathological interpretation of results. Thereby, we aim to facilitate the implementation of FISH-based 1p 19q testing for clinical purposes in standard neuropathology laboratories without special focus on brain tumor research.

BACKGROUND: Atypical teratoid/rhabdoid tumors are highly malignant embryonal central nervous system (CNS) tumors that were defined as an entity in 1996. As compared with other malignant CNS tumors, their biological behavior is particularly aggressive, but patients may benefit from an intensified treatment. Atypical teratoid/rhabdoid tumors display a complex histomorphology, which renders them prone to misdiagnosis. They occur predominantly in young children, with an estimated prevalence of 1% to 2% among all pediatric CNS tumors. However, population-based data on the incidence of these tumors are not yet available. METHODS: A nation-wide survey of malignant high-grade CNS tumors (World Health Organization grade III/IV), diagnosed in children (aged birth to 14 years) from 1996 to 2006 was conducted by the Austrian Brain Tumor Registry. A central histopathology review was performed including the assessment of SMARCB1 (INI1) protein status. RESULTS: A total of 311 newly diagnosed, malignant CNS tumors were included. Atypical teratoid/rhabdoid tumors constituted the sixth most common entity (6.1%), referring to an age-standardized incidence rate of 1.38 per 1,000,000 person-years in children. Peak incidence was found in the birth to 2 years age group, where they were as common as CNS primitive neuroectodermal tumors and medulloblastomas. A total of 47.4% of atypical teratoid/rhabdoid tumors were initially diagnosed, whereas 52.6% were retrospectively detected by the central review. The 5-year survival of atypical teratoid/rhabdoid tumor patients was 39.5%, with 66.7% in the correctly diagnosed group versus 15.0% in the not recognized group (P = .0469). CONCLUSIONS: Clinicians and pathologists should be aware of the high incidence of atypical teratoid/rhabdoid tumors in young children to optimize diagnostic and therapeutic management of patients with these tumors. Cancer 2010. © 2010 American Cancer Society.

Epigenetic profiling has shown that a proportion of cases diagnosed as CNS PNET in the past can be assigned to other tumour entities with similar morphological appearance. In an international effort to re-analyze CNS-PNET aiming for disease-specific re-evaluation of survival data and the development of diagnostic guidelines providing the basis for improved therapeutic approaches, 256 tumours diagnosed and treated as CNS-PNET in the last two decades in 17 countries were reviewed by a panel of neuropathologists according to today’s standards of clinical neuropathological diagnostics including immunohistochemical and molecular pathological assays. The majority of cases were also independently analyzed by methylation array hybridization and classified by random forest algorithm. In this unique cohort, we identified 20 different tumor entities including frequent high grade gliomas. 41% of cases were confirmed as CNS-PNET (now termed CNS-embryonal tumors (CNS-ET) according to the revised WHO-classification) representing two main entities: ETMR displayed typical histopathological features, LIN28A expression and/or C19MC alteration. The other represented a group of tumors with variable degrees of differentiation along neuroblastic/ganglionic lines, corresponding to the WHO diagnoses CNS-(Ganglio)-neuroblastoma or CNS-ET, NOS. The vast majority of these tumors could be assigned to the FOXR2 CNS-NB group by methylation array-based classification. Crossvalidation of neuropathological and epigenetic classification proved that methylation classification represents a useful complimentary tool in the differential diagnosis of CNS-ET. Re-evaluation of prototypic tumors and cases with discrepant diagnoses enabled us to develop an optimized diagnostic algorithm to securely delineate this tumor type from other entities with largely divergent clinical and biological behaviour.

Patients with recurrent malignant CNS tumors have a poor prognosis irrespective of salvage therapy applied. We used a metronomic antiangiogenic combination therapy and report on the response of individual tumor types to this approach. Since 2006, 81 patients with various recurrent malignant brain tumors started treatment with an antiangiogenic multidrug-regimen at the Medical University of Vienna. Therapy consisted of daily oral thalidomide, fenofibrate, celecoxib, and 21-day cycles of low dose oral etoposide alternating with cyclophosphamide augmented with IV bevacizumab and intraventricular therapy (etoposide and liposomal cytarabine). Excluding the 10 patients with recurrent medulloblastoma treated in the formal international protocol (MEMMAT; ClinicalTrials.gov Identifier: NCT01356290), 71 patients were treated according to the same strategy “off trial”. Diagnoses were medulloblastoma (n=20), atypical teratoid rhabdoid tumor (ATRT) (n=11), ependymoma (n=9), high grade glioma/diffuse intrinsic pontine glioma (HGG/DIPG) (n=9), and various other entities in the remaining patients. As of the end of 2017, 3-year and 5-year OS for the 20 patients with recurrent medulloblastoma was 64.2 ± 10.9% and for the 11 patients with recurrent ATRT 45.7 ± 16.6% and 30.5 ± 16.7%, respectively. Remission could be maintained after discontinuation of treatment in a certain percentage of patients with medulloblastoma, ATRT and ependymoma. Patients with HGG and DIPG did not respond to this approach. The proposed antiangiogenic regimen seems most promising in medulloblastoma and ATRT and possibly also ependymoma. In a number of other tumor entities time to progression could be prolonged while maintaining good quality of life.

BACKGROUND: Malignant brain tumors carry a high risk for leptomeningeal dissemination, but tumor cells floating in the CSF are often not affected by systemic and/or antiangiogenic chemotherapy. Since liposomal cytarabine was removed from the market, alternatives for intraventricular therapy are desperately needed. We report on our experience with an intraventricular therapy consisting of alternating cycles of etoposide, aqueous cytarabine and topotecan. PATIENTS AND METHODS: Between 2008 and 2017, 26 patients aged 1 to 17 years (median 7 years) with various malignant brain tumors received intraventricular therapy via an Ommaya reservoir, consisting of alternating etoposide 0.5mg on five consecutive days (1 and 2 and 1 and 2 and

Medulloblastoma is the most frequent malignant paediatric brain tumour. The activation of the Wnt/β-catenin pathway occurs in 10-15% of medulloblastomas and has been recently described as a marker for favourable patient outcome. We report a series of 72 paediatric medulloblastomas evaluated for β-catenin protein expression, CTNNB1 mutations, and comparative genomic hybridization. Gene expression profiles were also available in a subset of 40 cases. Immunostaining of β-catenin showed extensive nuclear staining (>50% of the tumour cells) in six cases and focal nuclear staining (

Adenoviruses (AdVs) contain genes coding for proteins with transforming potential, and certain AdV serotypes have been shown to induce tumors in rodents. However, data on the possible oncogenicity of AdVs in humans are scarce. We have therefore employed a real-time quantitative PCR (RQ-PCR) assay permitting highly sensitive detection of all 51 currently known human AdV serotypes to screen more than 500 tumor specimens derived from 17 different childhood cancer entities including leukemias, lymphomas, and solid tumors. Most tumor entities analyzed showed no evidence for the presence of AdV sequences, but AdV DNA was detected by RQ-PCR in different brain tumors including 25/30 glioblastomas, 22/30 oligodendrogliomas, and 20/30 ependymomas. Nonmalignant counterparts of AdV-positive brain tumors, including specimens of ependymal cells, plexus choroideus, and periventricular white matter, were screened for control purposes and revealed the presence of AdV DNA in most specimens tested. Identification of the AdV types present in positive malignant and nonmalignant brain tissue specimens revealed predominantly representatives of species B and D and, less commonly, C. To exclude contamination as a possible cause of false-positive results, specimens with AdV sequences detectable by PCR were subsequently analyzed by in situ hybridization, which confirmed the PCR findings in all instances. The central nervous system appears to represent a common site of AdV infection with virus persistence, thus providing the first evidence for the possible contribution of AdVs to the multistep process of tumor pathogenesis in brain tissue.

BACKGROUND: Ependymomas are the third most common CNS tumors in children. To date, extent of resection and patient age are the most important prognostic factors. To refine treatment strategies and improve patient outcome molecular markers are needed. Recently, the prognostic impact of tenascin-C (TNC) expression and gain of chromosome 1q have been described. Additionally, different molecular subgroups in supra-, infratentorial and spinal ependymomas have been identified including two subgroups characterized by RELA and YAP1 fusion genes in supratentorial cases. METHODS: We have analyzed a series of 75 pediatric ependymomas including 52 infra- and 23 supratentorial tumors. Patient age ranged between 0.9 and 21 years. FFPE sections were analysed using 1q25/1p36 FISH probes and antibodies against TNC, LAMA2, NF-κB, L1CAM and claudin-5. Immunohistochemical expression of LAMA2, NF-κB, L1CAM and claudin-5 was analyzed in additional 12 supratentorial ependymomas. RESULTS: 1q gain was found in 16%, TNC and Lama2 expression in 67% and 34%, respectively. Gain of 1q and TNC expression were predominantly detectable in infratentorial, whereas claudin-5 was almost exclusively expressed in supratentorial tumors. Claudin5, NF-κB and L1CAM expression was present in 68.6%, 48.6%, and 68.6% of all 35 supratentorial tumors, and a significant correlation between these markers was found. In two tumors with claudin5 and L1CAM expression RT-PCR verified the presence of a RELA fusion, thus confirming claudin5 and L1CAM as markers for tumors with RELA fusion. Patients with 1q gain and TNC expression had a significantly shorter overall survival, whereas no prognostic impact for LAMA2 and claudin5/L1CAM/ NF-κB was found. CONCLUSIONS: We confirm the prognostic impact of 1q gain and TNC expression in pediatric ependymomas and show that supratentorial ependymomas with RELA fusion can be recognized by L1CAM/claudin-5 expression. Nevertheless, there was no significant difference in outcome between supratentorial tumors with and without RELA fusion.

Immunohistochemical lack of nuclear INI1 protein expression has been recently described as characteristic finding in atypical teratoid/rhabdoid tumors (AT/RTs), and has been suggested as useful marker to distinguish AT/RTs from other malignant pediatric central nervous system (CNS) tumors. In this study, we examined a large series of malignant pediatric CNS tumors to determine the immunohistochemical expression of INI1 protein in different malignant pediatric tumor entities. Archival paraffin-embedded biopsy specimens of 289 malignant pediatric CNS tumors including medulloblastomas, supratentorial primitive neuroectodermal tumors, glioblastomas, anaplastic astrocytomas, anaplastic ependymomas, choroid plexus carcinomas, germ cell tumors, and AT/RTs were analyzed immunohistochemically for expression of nuclear INI1 protein. Positive INI1 staining was observed in 263 tumors. Lack of INI1 protein was detectable in 26 tumors. Seventeen of the 26 tumors showed morphologically characteristic features of AT/RTs, whereas 9 embryonal tumors did not display rhabdoid features. Tumors without rhabdoid phenotype but lack of INI1 showed an aggressive clinical course and poor response to conventional treatment regimens. In summary, immunohistochemical expression of INI1 protein is lacking in tumors displaying characteristic morphologic features of AT/RT. Furthermore, a certain number of embryonal tumors without rhabdoid features but lack of INI1 protein and aggressive biologic behavior can be detected. We conclude that INI1 protein analysis should be routinely performed in all malignant pediatric embryonal CNS tumors to detect cases with lack of INI1 protein, because patients with these tumors are likely to benefit from intensified treatment.

Malignant gliomas may manifest at any age including congenital and childhood cases. Peak incidence is, however, in adults older than 40 years. Males are more frequently affected than females. The sole unequivocal risk factor is therapeutic ionizing irradiation. Malignant gliomas comprise a spectrum of different tumor subtypes. Within this spectrum, glioblastoma, anaplastic astrocytoma and anaplastic oligodendroglioma share as basic features preferential location in cerebral hemispheres, diffuse infiltration of brain tissue, fast tumor growth with fatal outcome within months or years. Invasion is regarded as one of the main reasons for poor therapeutic success, because it makes complete surgical removal of gliomas impossible. Invasion of glioma cells requires interaction with the extracellular matrix and with surrounding cells of the healthy brain tissue. Vascular proliferates and tissue necrosis are characteristic features of malignant gliomas, in particular glioblastoma. These features are most likely the consequence of rapidly increasing tumor mass that is inadequately oxygenized by the preexisting vasculature. In malignant glioma, distinct molecular pathways including the p53 pathway, the RB pathway and the EGFR pathway show frequent alterations that seem to be pathogenetically relevant. Methylguanine-methyltransferase (MGMT) promoter methylation status in glioblastoma and 1p19q deletion status in anaplastic oligodendroglioma are associated with response to chemotherapy. The role of neuropathology and neurobiology in neurooncology is 1. to provide a clinically meaningful classification of brain tumors on basis of pathobiological factors, 2. to clarify etiology and pathogenesis of brain tumors as rational basis for development of new diagnostic tests and therapies, and 3. to translate testing for new clinically relevant molecular parameters into clinical application.

Aims : NeuN is considered to be a marker of neuronal differentiation in brain tumours. Our aim was to perform, for the first time, a systematic and comparative analysis of NeuN expression in all major brain tumour subtypes to provide guidance for the rational use of NeuN immunohistochemistry in diagnostic histopathology. Methods and results : Anti-NeuN immunohistochemistry was performed on paraffin-embedded biopsy specimens of 106 diffuse astrocytomas, 100 pilocytic astrocytomas, 107 ependymomas, 59 1p-aberrant oligodendroglial neoplasms, 115 glioblastomas, 115 medulloblastomas, 14 gangliogliomas/gangliocytomas and 10 central neurocytomas. We found no NeuN expression in pilocytic astrocytoma, whereas all other investigated tumour subtypes showed focal or widespread expression in varying proportions of cases. Comparing NeuN expression in clear cell tumours, widespread NeuN expression had a positive predictive value of 76.9% (95% confidence interval 46.2, 95.0) for central neurocytoma. Lack of NeuN expression had a positive predictive value of 87.3% (76.5, 94.4) for oligodendroglioma. Conclusions : Immunohistochemistry can detect NeuN expression in all major brain tumour subtypes except pilocytic astrocytoma. In the individual case, assessment of NeuN expression may be helpful in the differential diagnosis of clear cell primary brain tumours but does not seem to be useful for the differential diagnosis of other brain tumour subtypes.

BACKGROUND Hot-spot microvessel density (MVD) and vascular patterns have been reported as histopathologic factors that influence prognosis in retrospective series of malignant gliomas. To investigate clinical utility, the authors systematically studied observer agreement on MVD and vascular patterns and the influence of repeatedly assessed data on patient outcomes in 2 independent glioblastoma series. METHODS MVD and vascular patterns were assessed retrospectively by 5 observers in 1) a retrospectively compiled glioblastoma series that included 110 patients and 2) a glioblastoma series that included 233 patients who were treated within a randomized trial. MVD was determined in the field of greatest density (“hot-spot”). Predominantly classic or bizarre vascular patterns were determined by using a previously defined algorithm. RESULTS Observer agreement on MVD was highly variable (range of κ values, 0.464-0.901). The worst observer agreement was achieved when both the selection of hot-spots and MVD counts were performed independently. Survival analysis did not show a consistent association between repeatedly assessed MVD and patient outcome. Observer agreement on vascular patterns was poor (κ = 0.297). Survival analysis did not show a consistent association between repeatedly assessed vascular patterns and patient outcome. CONCLUSIONS Observer agreement on hot-spot MVD and vascular patterns in patients with glioblastoma was poor in independent assessments. MVD and vascular patterns were not associated consistently with patient outcome. Based on these findings, the authors concluded that poor observer agreement limits the clinical utility of histopathologically assessed hot-spot MVD and vascular patterns as prognostic factors in patients with glioblastoma. Improved methodologies for morphologic assessment of glioblastoma vascularization need to be identified. Cancer 2006. © 2006 American Cancer Society.

Inhibition of tyrosine kinase (TK) receptors by synthetic small molecules has become a promising new therapy option in oncology. The TK inhibitor imatinib mesylate selectively targets PDGFR-alpha, -beta, c-kit, c-abl and arg and has proven successful in the treatment of chronic myeloid leukaemia. In recurrent glioblastoma, phase II therapy trials using imatinib mesylate have been initiated. As only a fraction of patients seems to benefit from imatinib mesylate therapy and due to potential side effects and high costs of imatinib mesylate therapy, selection of the right patients is important. The goal of our study was to assess systematically immunohistochemical expression of the major TKs targeted by imatinib mesylate in glioblastoma, as expression of these factors could be used to select patients for imatinib mesylate therapy. In a cohort of 101 glioblastoma patients, anti-PDGFR-alpha, -beta, c-kit, c-abl and arg protein immunohistochemistry was performed. Expression of these proteins was assessed semi-quantitatively and correlated with patient survival.PDGFR-alpha and arg expression in tumor cells was widespread in 1/101 cases, respectively. Focal PDGFR-alpha, -beta, c-kit, c-abl and arg immunolabeling was detected in 25/101, 19/101, 4/101, 7/101 and 31/101 cases, respectively. Statistical analysis did not reveal any correlation between expression of the TKs and patient survival. We show here for the first time in a large series of glioblastomas that PDGFR-alpha, -beta, c-kit, c-abl and arg expression is immunohistochemically detectable in a fraction of cases. The value of anti-tyrosine kinase immunolabeling as predictive factor for patient selection remains to be clarified by comparative analysis of tumor tissue of therapy-responders versus non-responders.

Purpose: Skeletal muscle affection already in the eosinophilic stage of Churg–Strauss syndrome (CSS) is unusual. Case report: In a 36-year-old woman with a history of recurrent bronchial infections since childhood, recurrent poly-sinusitis and nasal polyps, and bronchial asthma, easy fatigability, weakness of the lower arms and lower legs, generalized myalgias with predominance of the lower arms, recurrent vertigo and falls developed. There was recurrently elevated creatine-kinase, glutamate-oxalate-transaminase, aldolase, lactate-dehydrogenase, eosinophilic granulocyte-count, thrombocyte-count, cholesterol, and blood sedimentation rate. Histologically polyps showed diffuse infiltrations of eosinophils exclusively. Muscle biopsy revealed grouped atrophic fibers, necrotic fibers, rarely regenerating fibers, epitheloid cells and rarely perimysial eosinophilic granulozytes. According to established criteria, CSS was diagnosed. Conclusions: This case shows that affection of the skeletal muscle in CSS, may manifest as easy fatigability, myalgias, and recurrently elevated CK, and that skeletal muscle involvement may be a dominant feature not only of the vasculitic but also of the eosinophilic stage of CSS.

The basis of human prion diseases affecting the nervous system is accumulation of a disease-associated conformer (PrPSc) of the normal cellular prion protein (PrPC). Earlier studies demonstrated increased expression of PrPC in inclusion body myositis (IBM), dermato-, and polymyositis, as well as neurogenic muscle atrophy. To define the spectrum and reliability of PrPC immunoreactivity, its expression was examined systematically in a series of pathologically characterized muscular disorders by means of immunohistochemistry, confocal laser microscopy, and immunogold electron microscopy. Anti-PrPC immunolabelling of rimmed vacuoles was observed in IBM, inclusions of myofibrillary myopathy, targets, regenerating, and atrophic fibres, mononuclear cells, in addition to ragged red fibres in mitochondrial myopathies, and focal sarcolemmal immunostaining in non-diseased controls. Quantitative analysis demonstrated that, in neurogenic muscle lesions, anti-PrPC staining detects a significantly broader spectrum of fibres than anti-vimentin or anti-NCAM. In dystrophic muscle, PrPC expression was mainly restricted to regenerating fibres. In IBM, PrPC expression was not confined to rimmed vacuoles or vacuolated fibres and only a small percentage (7.1%) of rimmed vacuoles were PrPC positive. Ultrastructurally, PrPC was observed in the cytoplasm of lymphocytes, in the myofibrillar network of targets, and in rimmed vacuoles. Knowledge of disease circumstances with altered expression of PrPC is important in the setting of a potentially increased chance for extraneural PrPC–PrPSc conversion. In addition, our observations suggest that PrPC may have a general stress–response effect in various neuromuscular disorders. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clear cell histology is the hallmark of oligodendroglioma (OG) but also characterizes clear cell ependymoma (CCE) and central neurocytoma (CN). Immunohistochemistry for glial and neuronal proteins may support differential diagnosis. We investigated systematically diagnostic value and limits of immunohistochemistry using representative tumor specimens (>1 cm in diameter) of well-defined OGs, CCEs, and CNs (n=10, respectively). Antibodies comprised anti-neuron specific nuclear protein (NEUN), anti-synaptophysin, anti-neuron-specific enolase, anti-microtubule-associated protein 2, anti-phosphorylated neurofilament protein, anti-non-phosphorylated neurofilament protein, anti-glial fibrillary acidic protein (GFAP), anti-S100 protein, anti-vimentin (VIM), and anti-epithelial membrane antigen (EMA). Among the panel of antibodies anti-NEUN, anti-VIM and anti-EMA proved most useful for differential diagnosis. Prominent (>90%) anti-NEUN immunolabeling of tumor cells clearly distinguished CNs from OGs and CCEs. Anti-VIM immunolabeling and a characteristic cytoplasmic dot-like anti-EMA immunoreactivity pattern of tumor cells were detectable only in OGs and CCEs. Furthermore, prominent anti-VIM immunoreactivity and anti-EMA cell membrane staining including ring-like staining pattern is characteristic for CCEs. Additionally, a widespread gliofibrillary and minigemistocytic cytoplasmic anti-GFAP immunostaining pattern is restricted to some OGs. Our data indicate that immunohistochemistry using anti-NEUN, anti-VIM, and anti-EMA on representative tumor specimens allows clear-cut distinction of CNs vs OGs and CCEs. Anti-VIM, anti-EMA, and anti-GFAP support differential diagnosis of OGs vs CCEs. Nevertheless, it is noted that due to focal expression of glial proteins in CNs and, conversely, of neuronal proteins in OGs and CCEs, immunohistochemistry is of limited value on small tumor specimens.

BACKGROUND: Prognosis of patients with recurrent medulloblastoma and atypical teratoid rhabdoid tumor (ATRT) is dismal despite intensive therapy including high-dose chemotherapy with stem cell rescue. We report on 28 patients with recurrent medulloblastoma and ATRT treated with an alternative approach to conventional chemotherapy that targets neovascularisation by interfering with tumor angiogenesis at various levels. Patients and METHODS: From 11/2006 to 06/2016, 28 patients were diagnosed with recurrent embryonal tumors, 20 with a recurrent medulloblastoma (13 first, 7 multiple recurrences) and eight with recurrent ATRT (5 first, 3 multiple), three had germ line mutations. Treatment consisted of an antiangiogenic multidrug-regime including IV bevacizumab, oral thalidomide, celecoxib, fenofibrate, and etoposide alternating with cyclophosphamide, and augmented with intraventricular therapy (etoposide and liposomal cytarabine). Median age at start of antiangiogenic therapy was 10 (1–24) years for medulloblastoma and 1.5 (1–13) years for ATRT. Results: As of 11/2016, 12/20 patients with medulloblastoma are alive at a median of 25 (12–97) months after their last recurrence. 8/12 surviving patients are currently in CR for 97, 94, 93, 29, 27, 23, 19 and 18 months, five off therapy for 79, 62, 60, 22 and 18 months, three are in PR 23, 12 and 2 months after their last recurrence and one patient has stable disease 12 months after her last recurrence. 5-year-OS is 57.6 ± 13.2%. One patient died of an accident in CR 23 months after initiation of antiangiogenic therapy and one patient with a very good PR died of a septicemia seven months after his last recurrence. Two patients had prior been treated with the same antiangiogenic approach and had recurred 67 and 40 months after their last recurrence while off therapy for 36 and 21 months and both patients are in remission again, one off therapy for 18 months. 3/8 patients with ATRT are alive. Follow-up since last recurrence is 72, 27 and 24 months and all patients are off therapy for 52, 14 and 13 months. One patient died of another cause without evidence of tumor at autopsy 54 months after recurrence and while off therapy for 46 months. One surviving patient with a germ line mutation and a fourth recurrence was prior treated with the same approach albeit without intrathecal therapy. He recurred 78 months after his last recurrence while off therapy for 36 months. He is again in CR and off therapy for 13 months. Therapy is primarily outpatient, was generally well tolerated, and toxicities were manageable. CONCLUSION: The proposed antiangiogenic regimen is currently being evaluated for medulloblastomas in an international phase II protocol (MEMMAT; ClinicalTrials.gov Identifier: NCT01356290). The same approach seems to be also efficacious in recurrent ATRTs and warrants further evaluation.

Children with relapsed malignant brain tumours have a poor prognosis despite intensive treatment including high-dose chemotherapy with stem cell rescue [1, 2]. Angiogenesis, the formation of new blood vessels, is an important component of normal physiological processes such as wound healing and development. Moreover, tumour growth and metastasis is closely related to formation of new blood vessels [3, 4]. Antiangiogenic therapy inhibits neovascularization, thereby inhibiting tumour progression indirectly [5]. The term metronomic chemotherapy refers to the chronic administration of chemotherapeutic agents at relatively low, minimally toxic doses, and without prolonged drug-free breaks. Beside the antiangiogenic effect, metronomic chemotherapy has been shown to modulate anti-tumoural immunity and has the ability to induce tumour dormancy [6]. The combination of agents used in our metronomic antiangiogenic therapy is based on a four-drug regimen (thalidomide, celecoxib, etoposide and cyclophosphamide) published by Kieran et al. in 2005 [7]. We augmented this regimen with bevacizumab, fenofibrate, and intrathecal therapy with the goal to improve progression-free survival for patients with recurrent or refractory CNS tumours for whom no curative therapy is available. We report on our experience with an antiangiogenic metronomic chemotherapy for paediatric patients with recurrent CNS tumours of different histologies.