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Large-scale molecular profiling studies in recent years have shown that central nervous system (CNS) tumors display a much greater heterogeneity in terms of molecularly distinct entities, cellular origins and genetic drivers than anticipated from histological assessment. DNA methylation profiling has emerged as a useful tool for robust tumor classification, providing new insights into these heterogeneous molecular classes. This is particularly true for rare CNS tumors with a broad morphological spectrum, which are not possible to assign as separate entities based on histological similarity alone. Here, we describe a molecularly distinct subset of predominantly pediatric CNS neoplasms (n = 60) that harbor PATZ1 fusions. The original histological diagnoses of these tumors covered a wide spectrum of tumor types and malignancy grades. While the single most common diagnosis was glioblastoma (GBM), clinical data of the PATZ1-fused tumors showed a better prognosis than typical GBM, despite frequent relapses. RNA sequencing revealed recurrent MN1:PATZ1 or EWSR1:PATZ1 fusions related to (often extensive) copy number variations on chromosome 22, where PATZ1 and the two fusion partners are located. These fusions have individually been reported in a number of glial/glioneuronal tumors, as well as extracranial sarcomas. We show here that they are more common than previously acknowledged, and together define a biologically distinct CNS tumor type with high expression of neural development markers such as PAX2, GATA2 and IGF2. Drug screening performed on the MN1:PATZ1 fusion-bearing KS-1 brain tumor cell line revealed preliminary candidates for further study. In summary, PATZ1 fusions define a molecular class of histologically polyphenotypic neuroepithelial tumors, which show an intermediate prognosis under current treatment regimens.

Contains fulltext : 225888.pdf (Publisher’s version ) (Open Access), AIMS: Methylation profiling (MP) is increasingly incorporated in the diagnostic process of central nervous system (CNS) tumours at our centres in The Netherlands and Scandinavia. We aimed to identify the benefits and challenges of MP as a support tool for CNS tumour diagnostics. METHODS: About 502 CNS tumour samples were analysed using (850 k) MP. Profiles were matched with the DKFZ/Heidelberg CNS Tumour Classifier. For each case, the final pathological diagnosis was compared to the diagnosis before MP. RESULTS: In 54.4% (273/502) of all analysed cases, the suggested methylation class (calibrated score ≥0.9) corresponded with the initial pathological diagnosis. The diagnosis of 24.5% of these cases (67/273) was more refined after incorporation of the MP result. In 9.8% of cases (49/502), the MP result led to a new diagnosis, resulting in an altered WHO grade in 71.4% of these cases (35/49). In 1% of cases (5/502), the suggested class based on MP was initially disregarded/interpreted as misleading, but in retrospect, the MP result predicted the right diagnosis for three of these cases. In six cases, the suggested class was interpreted as 'discrepant but noncontributory'. The remaining 33.7% of cases (169/502) had a calibrated score <0.9, including 7.8% (39/502) for which no class indication was given at all (calibrated score <0.3). CONCLUSIONS: MP is a powerful tool to confirm and fine-tune the pathological diagnosis of CNS tumours, and to avoid misdiagnoses. However, it is crucial to interpret the results in the context of clinical, radiological, histopathological and other molecular information.

Aims: Methylation profiling (MP) is increasingly incorporated in the diagnostic process of central nervous system (CNS) tumours at our centres in The Netherlands and Scandinavia. We aimed to identify the benefits and challenges of MP as a support tool for CNS tumour diagnostics. Methods: About 502 CNS tumour samples were analysed using (850 k) MP. Profiles were matched with the DKFZ/Heidelberg CNS Tumour Classifier. For each case, the final pathological diagnosis was compared to the diagnosis before MP. Results: In 54.4% (273/502) of all analysed cases, the suggested methylation class (calibrated score ≥0.9) corresponded with the initial pathological diagnosis. The diagnosis of 24.5% of these cases (67/273) was more refined after incorporation of the MP result. In 9.8% of cases (49/502), the MP result led to a new diagnosis, resulting in an altered WHO grade in 71.4% of these cases (35/49). In 1% of cases (5/502), the suggested class based on MP was initially disregarded/interpreted as misleading, but in retrospect, the MP result predicted the right diagnosis for three of these cases. In six cases, the suggested class was interpreted as ‘discrepant but noncontributory’. The remaining 33.7% of cases (169/502) had a calibrated score <0.9, including 7.8% (39/502) for which no class indication was given at all (calibrated score <0.3). Conclusions: MP is a powerful tool to confirm and fine-tune the pathological diagnosis of CNS tumours, and to avoid misdiagnoses. However, it is crucial to interpret the results in the context of clinical, radiological, histopathological and other molecular information.

Histiocytosis is a heterogeneous group of disease entities, comprised by two main categories, namely Langerhans and non-Langerhans cell histiocytoses. Central nervous system involvement in histiocytosis is considered very rare and is often secondary to affection of anatomically related bone structures and/or multi-organ disease. We present a never-before described case of rare childhood histiocytosis with hybrid features of Langerhans cell histiocytosis and juvenile xanthogranuloma confined to the central nervous system in a 2- and a half-year-old boy with distinct treatment response to clofarabine. The case also emphasizes the diagnostic significance of stereotactic brain biopsy.

BACKGROUND: The aim of this study of third ventricular colloid cysts (TVCC) from a defined population was to estimate the incidence, the presenting features, the surgical treatment, the treatment related complications, and the clinical and surgical outcomes.METHODS: A reprospective study of 32 consecutive primary surgeries for TVCC was performed at Oslo University Hospital in the time period 2002-2015.RESULTS: The estimated incidence rate for TVCC was 0.9 per million. Mean age was 41 years and the male-to-female ratio was 1:1.5. The most common presenting symptoms were headache (100%), ataxia (25%), reduced level of consciousness (22%), and impaired vision (19%). The surgical mortality was 0%. Gross total resection (GTR) was achieved in 69% based on intraoperative findings and in 81% based on postoperative imaging. The rate of surgery-related complications was 13%. There was no statistically significant difference between microsurgery and endoscopic surgery with respect to surgery-related complications and grade of resection. At time of follow-up, all patients were able to care for themselves.CONCLUSIONS: Due to the risk of acute neurological deterioration and sudden death, surgical treatment is recommended for patients with symptomatic TVCC. This study shows that surgical resection can be performed with a fairly low risk and with a good long-term outcome.

Item does not contain fulltext, Primitive neuroectodermal tumors of the central nervous system (CNS-PNETs) are highly aggressive, poorly differentiated embryonal tumors occurring predominantly in young children but also affecting adolescents and adults. Herein, we demonstrate that a significant proportion of institutionally diagnosed CNS-PNETs display molecular profiles indistinguishable from those of various other well-defined CNS tumor entities, facilitating diagnosis and appropriate therapy for patients with these tumors. From the remaining fraction of CNS-PNETs, we identify four new CNS tumor entities, each associated with a recurrent genetic alteration and distinct histopathological and clinical features. These new molecular entities, designated "CNS neuroblastoma with FOXR2 activation (CNS NB-FOXR2)," "CNS Ewing sarcoma family tumor with CIC alteration (CNS EFT-CIC)," "CNS high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1)," and "CNS high-grade neuroepithelial tumor with BCOR alteration (CNS HGNET-BCOR)," will enable meaningful clinical trials and the development of therapeutic strategies for patients affected by poorly differentiated CNS tumors.

OBJECTIVES: The prognostic value of acute postoperative seizures (APS) after epilepsy surgery is much debated. This study evaluated APS, defined as seizures in the first week post-surgery, as a predictor of long-term seizure outcome, and investigated the utility of other potential outcome predictors. MATERIALS AND METHODS: Medical records of 48 patients with temporal and extra-temporal epilepsy surgery were studied. Forty patients had lesional surgery. All had at least 2 year postoperative follow-up. RESULTS: At 2 year follow-up, 25 patients (53%) were seizure free. Univariate analysis showed that APS (P = 0.048), using ≥ six AEDs prior to surgery (P = 0.03), pathological postoperative EEG (P = 0.043) and female gender (P = 0.012) were associated with seizure recurrence. CONCLUSIONS: Univariate analysis indicate that APS, a high number of AEDs used prior to surgery, and pathological postoperative EEG are possible predictors of seizure recurrence after epilepsy surgery. Only gender retained significance in the multivariate analysis.

Gliosarcoma is a highly malignant brain tumor consisting of both a glioblastoma and a mesenchymal component. The latter typically resembles fibrosarcoma, but differentiation patterns resembling osteosarcoma, chondrosarcoma, angiosarcoma and rhabdomyosarcoma have also been described. Molecular-genetic studies have shown that both glioblastoma and the mesenchymal component share identical cytogenetic abnormalities or mutations, suggesting a monoclonal origin from glial cells. We report an unusual case of gliosarcoma that presented as a large intracerebral tumor with infiltration of the temporal bone and the soft tissues in the infratemporal fossa. Microscopically, the tumor consisted of alternating areas of glioblastoma and fibrosarcoma. Focally, areas ofosteosarcomatous and liposarcomatous differentiation were found. Although gliosarcoma with transcranial penetration is very rare, it should be suspected in case of intracranial tumor with glioblastoma-imaging features, infiltration of bone and extracranial growth. Our case of liposarcomatous differentiation in gliosarcoma--together with another very recently reported similar case--expands the morphologic heterogeneity of this peculiar brain tumor.