Pierwotne guzy pnia mózgu u dzieci w badaniu rezonansu magnetycznego

Background: Brain-stem gliomas constitute about 10-20% of CNS tumors. The most common site of tumor is the pons, followed by the midbrain and medulla. The aim of the study was to evaluate the variety of MR images of brain-stem gliomas in children depending on the localization according to the WHO classification. Materials/Method: We estimated MR examinations of 76 children (44 girls and 32 boys) with brain-stem tumors. Mean age was 7.8 years (range: 1-18.3 years). Examinations were performed with a 1.5 T scanner in the SE, FSE, and FLAIR sequences in T1- and T2-weighted images. Gadolinium was administered obligatory in each case. Results: Forty-four tumors were localized in the pons, 18 in the midbrain, and 14 in the medulla. No contrast enhancement was observed in 19 tumors in the pons, 3 in the midbrain, and 2 in medulla. In the other cases were varied patterns of contrast enhancement. In three cases, focal lesions were diagnosed, and in 9 cases exophytic tumors were seen. Conclusions: MR images of brain-stem gliomas are typical in the pediatric age group and allow recognizing these lesions properly. This is very important for making therapeutic decisions in these cases

TERT promoter mutations are highly recurrent in SHH subgroup medulloblastoma

Telomerase reverse transcriptase (TERT) promoter mutations were recently shown to drive telomerase activity in various cancer types, including medulloblastoma. However, the clinical and biological implications of TERT mutations in medulloblastoma have not been described. Hence, we sought to describe these mutations and their impact in a subgroup-specific manner. We analyzed the TERT promoter by direct sequencing and genotyping in 466 medulloblastomas. The mutational distributions were determined according to subgroup affiliation, demographics, and clinical, prognostic, and molecular features. Integrated genomics approaches were used to identify specific somatic copy number alterations in TERT promoter-mutated and wild-type tumors. Overall, TERT promoter mutations were identified in 21 % of medulloblastomas. Strikingly, the highest frequencies of TERT mutations were observed in SHH (83 %; 55/66) and WNT (31 %; 4/13) medulloblastomas derived from adult patients. Group 3 and Group 4 harbored this alteration in <5 % of cases and showed no association wit

Cytogenetic Prognostication Within Medulloblastoma Subgroups

PURPOSE: Medulloblastoma comprises four distinct molecular subgroups: WNT, SHH, Group 3, and Group 4. Current medulloblastoma protocols stratify patients based on clinical features: patient age, metastatic stage, extent of resection, and histologic variant. Stark prognostic and genetic differences among the four subgroups suggest that subgroup-specific molecular biomarkers could improve patient prognostication. PATIENTS AND METHODS: Molecular biomarkers were identified from a discovery set of 673 medulloblastomas from 43 cities around the world. Combined risk stratification models were designed based on clinical and cytogenetic biomarkers identified by multivariable Cox proportional hazards analyses. Identified biomarkers were tested using fluorescent in situ hybridization (FISH) on a nonoverlapping medulloblastoma tissue microarray (n = 453), with subsequent validation of the risk stratification models. RESULTS: Subgroup information improves the predictive accuracy of a multivariable survival model compared with clinical biomarkers alone. Most previously published cytogenetic biomarkers are only prognostic within a single medulloblastoma subgroup. Profiling six FISH biomarkers (GLI2, MYC, chromosome 11 [chr11], chr14, 17p, and 17q) on formalin-fixed paraffin-embedded tissues, we can reliably and reproducibly identify very low-risk and very high-risk patients within SHH, Group 3, and Group 4 medulloblastomas. CONCLUSION: Combining subgroup and cytogenetic biomarkers with established clinical biomarkers substantially improves patient prognostication, even in the context of heterogeneous clinical therapies. The prognostic significance of most molecular biomarkers is restricted to a specific subgroup. We have identified a small panel of cytogenetic biomarkers that reliably identifies very high-risk and very low-risk groups of patients, making it an excellent tool for selecting patients for therapy intensification and therapy de-escalation in future clinical trials