Expression of thyroid transcription factor 1 in primary brain tumours.
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BACKGROUND: Thyroid transcription factor 1 (TTF-1) is expressed in a proportion of carcinomas derived from follicular thyroid cells and respiratory epithelium. Immunohistochemical detection of this protein was shown previously to be a helpful aid in tumour diagnosis, specifically in deciding whether a tumour is primary to the lung/thyroid gland or metastatic. Recently, TTF-1 expression was also observed in certain areas of postnatal brain. AIM/METHOD: To investigate the expression of TTF-1 protein in a spectrum of 73 primary brain tumours including astrocytomas, glioblastomas, ependymomas, oligodendrogliomas, medulloblastomas, and gangliogliomas of different sites. RESULTS: All the tumours were negative for TTF-1 except for two ependymomas of the third ventricle. CONCLUSIONS: The expression of TTF-1 in brain tumours appears to be site specific rather than associated with tumour dedifferentiation. The presented expression of TTF-1 protein in certain primary brain tumours should be taken into consideration when interpreting the immunohistochemical staining of brain tumours of uncertain primary site. (+info)
Anaplastic ependymoma in the cervical spinal cord of a maltese dog.
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An 8-year and 6-month-old female Maltese dog showed a stoop with rigidity of her cervix and back. Neurologic examination showed loss of proprioception, and deficiency of pain response. Postmortem examination revealed the neoplastic mass replacing the central area in the cervical spinal cord at the level from 4th to 5th segments. Histologically, the mass was composed of neoplastic ependymal cells. The neoplastic cells showed marked atypism, and occasionally formed ependymal rosettes. Based on the morphologic features, the tumor was diagnosed as anaplastic ependymoma. Immunohistochemistry showed that the neoplastic cells were negative for glial fibrillary acid protein, and slightly positive for vimentin and cytokeratin. (+info)
Large supratentorial ectopic ependymoma with massive calcification and cyst formation--case report.
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A 6-year-old boy presented with a large supratentorial ependymoma with massive calcification and central cyst formation manifesting as generalized convulsion and right hemiparesis. Computed tomography and magnetic resonance imaging showed a large, poorly enhanced, left frontal mass with massive calcification and a central cyst. Angiography revealed no extracranial blood supply to the tumor, which was supplied by branches of the left middle cerebral artery. The patient underwent total resection of the tumor, which was located in the parenchyma with no dural attachment. The tumor was clearly demarcated and dissected subpially from the surrounding brain parenchyma. The surgical findings suggested no relationship with the lateral ventricular system. Histological examination of the tumor demonstrated perivascular pseudorosette formation and mitosis with massive calcification, and immunocytochemical reactivity for glial fibrillary acidic protein and epithelial membrane antigen, but not synaptophysin. These findings were compatible with ependymoma, World Health Organization grade 2. Postoperative magnetic resonance imaging clearly showed that the tumor was located in the intradural, intraaxial space with no relationship to the ventricles. (+info)
A PDGFRA promoter polymorphism, which disrupts the binding of ZNF148, is associated with primitive neuroectodermal tumours and ependymomas.
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BACKGROUND: Platelet derived growth factor receptor alpha (PDGFRalpha) expression is typical for a variety of brain tumours, while in normal adult brain PDGFRalpha expression is limited to a small number of neural progenitor cells. The molecular mechanisms responsible for the PDGFRalpha expression in tumours are not known, but in the absence of amplification, changes in transcriptional regulation might be an important factor in this process. METHODS AND RESULTS: We have investigated the link between single nucleotide polymorphisms (SNPs) within the PDGFRalpha gene promoter and the occurrence of brain tumours (medulloblastomas, supratentorial primitive neuroectodermal tumours (PNETs), ependymal tumours, astrocytomas, oligodendrogliomas, and mixed gliomas). These SNPs give rise to five different promoter haplotypes named H1 and H2alpha-delta. It is apparent from the haplotype frequency distribution that both PNET (10-fold) and ependymoma (6.5-fold) patient groups display a significant over-representation of the H2delta haplotype. The precise functional role in PDGFRalpha gene transcription for the H2delta haplotype is not known yet, but we can show that the H2delta haplotype specifically disrupts binding of the transcription factor ZNF148 as compared to the other promoter haplotypes. CONCLUSIONS: The specific over-representation of the H2delta haplotype in both patients with PNETs and ependymomas suggests a functional role for the ZNF148/PDGFRalpha pathway in the pathogenesis of these tumours. (+info)
Long-term control of recurrent anaplastic ependymoma with extracranial metastasis: importance of multiple surgery and stereotactic radiosurgery procedures--case report.
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An 11-year-old Japanese girl presented with a right frontal lobe anaplastic ependymoma. The tumor was removed surgically. However, she developed a secondary lesion and extracranial metastasis in the cervical lymph node. In total, she underwent eight intracranial tumor removal procedures, five stereotactic radiosurgeries with six targets, and five cervical lymph node removal surgeries during the course of 7 years. She is currently alive with a good quality of life, and has no major neurological deficits except right facial nerve palsy. The combination of surgery and radiosurgery can achieve local control of anaplastic ependymoma. Multiple surgery or radiosurgery procedures can result in good outcome, if the tumor does not involve crucial structures, even if extracranial metastasis occurs. (+info)
Microarray analysis of pediatric ependymoma identifies a cluster of 112 candidate genes including four transcripts at 22q12.1-q13.3.
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Ependymomas are glial cell-derived tumors characterized by varying degrees of chromosomal abnormalities and variability in clinical behavior. Cytogenetic analysis of pediatric ependymoma has failed to identify consistent patterns of abnormalities, with the exception of monosomy of 22 or structural abnormalities of 22q. In this study, a total of 19 pediatric ependymoma samples were used in a series of expression profiling, quantitative real-time PCR (Q-PCR), and loss of heterozygosity experiments to identify candidate genes involved in the development of this type of pediatric malignancy. Of the 12,627 genes analyzed, a subset of 112 genes emerged as being abnormally expressed when compared to three normal brain controls. Genes with increased expression included the oncogene WNT5A; the p53 homologue p63; and several cell cycle, cell adhesion, and proliferation genes. Underexpressed genes comprised the NF2 interacting gene SCHIP-1 and the adenomatous polyposis coli (APC)-associated gene EB1 among others. We validated the abnormal expression of six of these genes by Q-PCR. The subset of differentially expressed genes also included four underexpressed transcripts mapping to 22q12.313.3. By Q-PCR we show that one of these genes, 7 CBX7(22q13.1), was deleted in 55% of cases. Other genes mapping to cytogenetic hot spots included two overexpressed and three underexpressed genes mapping to 1q31-41 and 6q21-q24.3, respectively. These genes represent candidate genes involved in ependymoma tumorigenesis. To the authors' knowledge, this is the first time microarray analysis and Q-PCR have been linked to identify heterozygous/homozygous deletions. (+info)
Alterations of protein 4.1 family members in ependymomas: a study of 84 cases.
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Ependymomas are common pediatric and adult CNS malignancies with a wide biologic spectrum that is often hard to predict using classic prognostic variables. The molecular pathogenesis is also poorly understood and few reproducible genetic alterations have been identified. The most common genetic alteration has been the loss of the Protein 4.1 family member, NF2, predominantly in spinal ependymomas. In contrast, a pilot study suggested that 4.1B deletions might be more common in intracranial ependymomas. These findings prompted us to study Protein 4.1 family members (NF2, 4.1B, 4.1R, 4.1G) in a larger cohort of 84 ependymomas (51 intracranial and 33 spinal; 11 WHO grade I, 43 grade II, 30 grade III). Fluorescence in situ hybridization was performed using NF2, 4.1B, 4.1R and 4.1G probes and immunohistochemical staining was performed in a subset using merlin, Protein 4.1B and Protein 4.1R antibodies. Additionally, frozen tissue from nine ependymomas (four intracranial and five spinal) was obtained for Western blot analysis for merlin, 4.1B and 4.1R expression. The majority of cases harbored one or more detectable genetic alterations, but we found that 4.1B gene deletions and 4.1R loss of expression were statistically more common in the pediatric vs adult, intracranial vs spinal, and grade III vs grade I/II subsets (P-values of 0.038 to <0.001). Also, 4.1G deletions were seen in 11/27 (41%) patients who either died of disease or had residual/recurrent tumor vs 5/41 patients with no evidence of disease at last follow-up (P=0.009). We conclude that alterations of Protein 4.1 family members are common in ependymal tumors and that specific alterations are associated with distinct clinicopathologic subsets. (+info)
Spinal tanycytic ependymoma with hematomyelia--case report--.
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A 58-year-old man presented with an extremely rare case of "pure type" spinal tanycytic ependymoma associated with hematomyelia manifesting as sensory disturbance of the bilateral hands and weakness of the right arm. Magnetic resonance imaging demonstrated a tumor in the spinal cord from C-2 to C-4 levels. The soft gelatinous tumor was subtotally resected and the adjacent chronic liquid hematoma was aspirated. The immunohistochemical and ultrastructural findings indicated a diagnosis of tanycytic ependymoma. (+info)