Time filter

Source Type

Pierscianek D.,International Agency for Research on Cancer | Kim Y.-H.,International Agency for Research on Cancer | Motomura K.,International Agency for Research on Cancer | Mittelbronn M.,Goethe University Frankfurt | And 11 more authors.
Brain Pathology | Year: 2013

Glioblastoma may develop rapidly without evidence for precursor lesions (primary glioblastomas), or progress from diffuse or anaplastic astrocytomas (secondary glioblastomas). Despite having distinct genetic profiles, these glioblastoma subtypes have similar histological features. We hypothesized that the highly malignant phenotype of glioblastoma may be attributable to genetic alterations that are common to both glioblastoma subtypes. In the present study, we first searched for commonly (>35%) amplified genes in glioblastomas with IDH1 mutation (a hallmark of secondary glioblastoma) and those without IDH1 mutation (typical for primary glioblastoma) in data from The Cancer Genome Atlas (TCGA). A total of 25 genes were identified, of which 21 were located at 7q31-34. We then screened 264 gliomas (70 glioblastomas, 112 diffuse astrocytomas, 82 oligodendrogliomas) for gain of the MET at 7q31.2 with quantitative polymerase chain reaction (PCR). MET gain was detected in primary glioblastomas (47%) and secondary glioblastomas (44%), suggesting that this genetic alteration plays a role in the pathogenesis of both glioblastoma subtypes. MET gain was also common in diffuse astrocytomas (38%), but less frequent in oligodendrogliomas (16%). MET gain in diffuse astrocytomas was associated with shorter survival (median, 43.0 vs. 70.7 months; P = 0.004), suggesting that MET gain is a useful prognostic marker for diffuse astrocytomas. © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology.

Harder A.,University of Munster | Wesemann M.,University of Munster | Hagel C.,Institute of Neuropathology | Schittenhelm J.,Institute of Pathology and Neuropathology | And 7 more authors.
American Journal of Surgical Pathology | Year: 2012

We analyzed the histologic features of peripheral nerve sheath tumors occurring in 14 patients with schwannomatosis. Among a total of 31 tumors, 19 tumors (61%) showed schwannoma-like nodules within a neurofibroma-like tumor, corresponding to hybrid neurofibroma/schwannoma. At least 1 hybrid tumor occurred in 10 of 14 (71%) schwannomatosis patients. We then retrieved cases of hybrid tumors without documented relation to schwannomatosis from our database and identified 41 tumors arising in 23 patients. More than half of these patients (14/23) were reported to suffer from multiple peripheral nerve sheath tumors, favoring a tumor syndrome. Indeed, analysis of clinical records revealed the diagnosis of neurofibromatosis type 2 (NF2) in 26% (6/23), neurofibromatosis type 1 (NF1) in 9% (2/23), definite schwannomatosis in 4% (1/23), and possible schwannomatosis in 13% (3/23) of patients with multiple nerve sheath tumors. Our findings suggest that hybrid neurofibroma/schwannoma represents a common tumor type in schwannomatosis and shows a striking association with neurofibromatoses. Copyright © 2012 by Lippincott Williams & Wilkins.

Stefanits H.,Medical University of Vienna | Ebetsberger-Dachs G.,Childrens and Maternity Hospital Linz | Weis S.,Institute of Pathology and Neuropathology | Haberler C.,Medical University of Vienna
Clinical Neuropathology | Year: 2014

We present an unusual medulloblastoma in a 3.9-year-old boy who had a 2-week history of nausea and vertigo. MRI revealed a 5×5.5×5 cm sized tumor located in the fourth ventricle and spinal leptomeningeal dissemination. The patient was treated according to the MET-HIT 2000-BIS4 protocol but showed tumor progression after 6 months and died 9 months postoperatively. Histopathologically and immunohistochemically, the tumor showed PNET-like areas with focal anaplasia, admixed rhabdomyoblastic and pigmented elements, cartilage and bone formation, as well as areas with neurocytic and glial differentiation. Neither CTNNB1 mutation nor MYCC/ MYCN amplification was detected. The combination of rhabdomyoblastic and melanotic elements in medulloblastoma is exceptionally rare. Although the histopathological features suggested a teratoid tumor, the endodermal cell lineage required for this diagnosis was not present. An atypical teratoid-rhabdoid tumor was ruled out due to the presence of the INI1- protein. Regarding the molecular profile with 1q and 17q chromosomal gains and loss of chromosome 8, this tumor could be compatible with a molecular medulloblastoma Group 3 or 4. Yet, it cannot be definitively ruled out that medulloblastomas with multi-lineage differentiation represent a distinct subgroup of medulloblastoma, and it remains to be clarified whether these tumors are associated with a distinct clinical behavior.

Spiegl-Kreinecker S.,Wagner Jauregg Hospital | Lotsch D.,Medical University of Vienna | Ghanim B.,Medical University of Vienna | Pirker C.,Medical University of Vienna | And 7 more authors.
Neuro-Oncology | Year: 2015

Background. Expression of the telomerase reverse transcriptase (TERT) might be altered by activating mutations of the rs2853669 polymorphism within the promoter region. Here we investigate the impact of these genomic alterations on telomerase activation and dissect their prognostic potential in glioblastoma (GBM). Methods. The respective TERT promoter region was sequenced in 126 GBM tissues and compared with clinical parameters and glioma biomarkers MGMT promoter methylation and IDH1 mutation. TERT mRNA expression, telomerase activity, and telomere lengths were determined by reverse transcriptase PCR, TRAP assay, and real-time PCR, respectively. Results. Seventy-three percent of GBM patients harbored TERT promoter mutations associated with enhanced telomerase activity and TERT mRNA expression but reduced telomere lengths (P <. 001 for all). Patients with mutated tumors exhibited significantly shorter overall survival in the entire cohort (11.5 vs 23.1 months; P <. 0001) and in the primary GBM patient subgroup lacking IDH1 mutations (n = 120; P =. 0084). This prognostic impact was confined to younger patients (aged <65 years), while the negative prognostic power of enhanced age at diagnosis was limited to those patients lacking TERT promoter mutations. Presence of the common single nucleotide polymorphism rs2853669, disrupting an endogenous Ets2 transcription factor-binding site, was associated with improved survival exclusively in patients with a wild-type TERT promoter. On the contrary, the shortest mean overall survival was detected in those patients harboring both an activating TERT promoter mutation and homozygous rs2853669 alleles. Conclusion. In summary, TERT promoter mutations are powerful prognosticators for worse course of disease in human GBM patients but their prognostic value is influenced by the rs2853669 polymorphism and age at diagnosis. © 2015 The Author(s).

Schittenhelm J.,University of Tubingen | Schwab E.I.,University of Tubingen | Tatagiba M.,Institute of Pathology and Neuropathology | Meyermann R.,University of Tubingen | And 2 more authors.
Journal of Neuropathology and Experimental Neurology | Year: 2013

Integrin inhibitors targeting αv series integrins are being tested for their therapeutic potential in patients with brain tumors, but pathologic studies have been limited by lack of antibodies suitable for immunohistochemistry (IHC) on formalin-fixed, paraffin-embedded specimens. We compared the expression of αv integrins by IHC in brain tumor and normal human brain samples with gene expression data in a public database using new rabbit monoclonal antibodies against αvβ3, αvβ5, αvβ6, and αvβ8 complexes using both manual and automated microscopy analyses. Glial tumors usually shared an αvβ3-positive/ αvβ5-positive/αvβ8-positive/αvβ6-negative phenotype. In 94 WHO (World Health Organization) grade II astrocytomas, 85 anaplastic astrocytomas WHO grade III, and 324 glioblastomas from archival sources, expression of integrins generally increased with grade of malignancy. Integrins αvβ3 and αvβ5 were expressed in many glioma vessels; the intensity of vascular expression of αvβ3 increased with grade of malignancy, whereas αvβ8 was absent. Analysis of gene expression in an independent cohort showed a similar increase in integrin expression with tumor grade, particularly of ITGB3 and ITGB8; ITGB6 was not expressed, consistent with the IHC data. Parenchymal αvβ3 expression and ITGB3 gene overexpression in glioblastomas were associated with a poor prognosis, as revealed by survival analysis (Kaplan-Meier logrank, p = 0.016). Together, these data strengthen the rationale for anti-integrin treatment of glial tumors. © 2013 American Association of Neuropathologists, Inc.

Discover hidden collaborations