Ependymoma

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Ependymoma

  • myxopapillary ependymoma
  • pediatric ependymoma


  • Selected Abstracts


    Highly cystic brain tumor: Rare histological features in an ependymoma

    NEUROPATHOLOGY, Issue 4 2007
    Dorel Arsene
    Ependymoma is a slowly growing tumor appearing mostly in children and young adults. Several histological patterns are described. We report a case with unusual microscopic features, composed mostly of multiple cysts. Ultrastructural and immunohistochemical examination confirmed the diagnosis. Neuropathologists should be aware of this particular change which can generate some diagnostic difficulties. [source]


    Telomerase Inhibition as a Novel Therapy for Pediatric Ependymoma

    BRAIN PATHOLOGY, Issue 4 2010
    Vincent C.H. Wong
    Abstract Ependymomas are the third most common pediatric brain tumor with an overall survival of ,50%. Recently, we showed that telomerase [human telomerase reverse transcriptase (hTERT)] expression is a predictor of poor outcome in pediatric ependymoma. Thus, we hypothesized that ependymomas with functional telomerase may behave more aggressively and that these patients may benefit from anti-telomerase therapy. To address our hypothesis, we investigated the effect of telomerase inhibition on primary ependymoma cells harvested at the time of surgery, as no animal models or established cell lines are readily available for this tumor. The cells were characterized for glial fibrillary acidic protein (GFAP) and hTERT expression, initial telomere length and telomerase activity. They were then subjected to telomerase inhibition (MST-312, 1 µM) and tested for effects on cell viability (MTT assay), proliferation (MIB-1), apoptosis (cleaved caspase 3) and DNA damage (,H2AX). After 72 h of telomerase inhibition, primary ependymoma cells showed a significant decrease in cell number (P < 0.001), accompanied by increased DNA damage (,H2AX expression) (P < 0.01) and decreased proliferative index (MIB-1) (P < 0.01). Half showed an increase in apoptosis (cleaved caspase 3). These data suggest that telomerase inhibition may be an effective adjuvant therapy in pediatric ependymoma, potentially inducing tumor growth arrest in the short term, independent of telomere shortening. [source]


    Unique Molecular Characteristics of Pediatric Myxopapillary Ependymoma

    BRAIN PATHOLOGY, Issue 3 2010
    Valerie N. Barton
    Abstract Myxopapillary ependymoma (MEPN) generally can be cured by gross total surgical resection and usually manifest a favorable prognosis. However, surgery is less curative in tumors that are large, multifocal or extend outside the thecal sac. Late recurrences may occur, particularly in pediatric patients. The role of adjuvant therapy is unclear in the clinical management of recurrent tumors. Clinical trial design requires a better understanding of tumor biology. Unique molecular features of MEPN were investigated by using microarray technology to compare the gene expression of five pediatric MEPN to 24 pediatric intracranial ependymoma (EPN). The upregulation of three genes of interest, homeobox B13 (HOXB13), neurofilament, light polypeptide (NEFL) and PDGFR,, was further studied by immunohistochemistry in a larger cohort that included adult MEPN and EPN specimens. Protein expression in MEPN was compared to subependymoma, spinal EPN, intracranial EPN and normal fetal and adult ependyma. Immunoreactivity for HOXB13, NEFL and PDGFR, was strongest in MEPN and virtually absent in subependymoma. Spinal and intracranial EPN generally expressed weak or focal staining. MEPN manifests unique gene and protein expression patterns compared to other EPNs. Aberrant expression of HOXB13 suggests possible recapitulation of developmental pathways in MEPN tumorigenesis. PDGFR, may be a potential therapeutic target in recurrent MEPN. [source]


    Localization of a putative low-penetrance ependymoma susceptibility locus to 22q11 using a chromosome 22 tiling-path genomic microarray

    GENES, CHROMOSOMES AND CANCER, Issue 4 2005
    Anneke C. J. Ammerlaan
    Ependymomas frequently display allelic loss of chromosome 22 in the absence of mutations in the known tumor-suppressor genes on chromosome 22, suggesting the role of an alternative predisposing gene or genes from this chromosome. In an effort to localize these genes, 37 ependymomas derived from 33 patients were analyzed for the presence of copy number changes by use of a high-resolution chromosome 22 genomic microarray. Eighteen ependymomas (49%) displayed an array-CGH profile consistent with monosomy of chromosome 22. However, in 10 of these tumors, the fluorescence ratios for 22q clones scored as deleted were different from those at the single gene copy level. This suggests either analysis of mixed populations of tumor and normal stromal cells or analysis of mixed tumor cell populations with different genetic profiles. Four ependymomas derived from two patients showed overlapping interstitial deletions of 2.2 Mb and ,510 kb. Further analyses revealed that these deletions were present in the constitutional DNA of these two patients as well as in some of their unaffected relatives. Detailed microsatellite analysis of these families refined the commonly deleted segment to a region of 320 kb between markers RH13801 and D22S419. Our results provide additional evidence for the involvement of genes on chromosome 22 in the development of ependymoma and suggest the presence of a low-penetrance ependymoma susceptibility locus at 22q11. © 2005 Wiley-Liss, Inc. [source]


    Telomerase Inhibition as a Novel Therapy for Pediatric Ependymoma

    BRAIN PATHOLOGY, Issue 4 2010
    Vincent C.H. Wong
    Abstract Ependymomas are the third most common pediatric brain tumor with an overall survival of ,50%. Recently, we showed that telomerase [human telomerase reverse transcriptase (hTERT)] expression is a predictor of poor outcome in pediatric ependymoma. Thus, we hypothesized that ependymomas with functional telomerase may behave more aggressively and that these patients may benefit from anti-telomerase therapy. To address our hypothesis, we investigated the effect of telomerase inhibition on primary ependymoma cells harvested at the time of surgery, as no animal models or established cell lines are readily available for this tumor. The cells were characterized for glial fibrillary acidic protein (GFAP) and hTERT expression, initial telomere length and telomerase activity. They were then subjected to telomerase inhibition (MST-312, 1 µM) and tested for effects on cell viability (MTT assay), proliferation (MIB-1), apoptosis (cleaved caspase 3) and DNA damage (,H2AX). After 72 h of telomerase inhibition, primary ependymoma cells showed a significant decrease in cell number (P < 0.001), accompanied by increased DNA damage (,H2AX expression) (P < 0.01) and decreased proliferative index (MIB-1) (P < 0.01). Half showed an increase in apoptosis (cleaved caspase 3). These data suggest that telomerase inhibition may be an effective adjuvant therapy in pediatric ependymoma, potentially inducing tumor growth arrest in the short term, independent of telomere shortening. [source]


    Low Frequency of Chromosomal Imbalances in Anaplastic Ependymomas as Detected by Comparative Genomic Hybridization

    BRAIN PATHOLOGY, Issue 2 2001
    Stefanie Scheil
    We screened 26 ependymomas in 22 patients (7 WHO grade I, myxopapillary, myE; 6 WHO grade II, E; 13 WHO grade III, anaplastic, aE) using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). 25 out of 26 tumors showed chromosomal imbalances on CGH analysis. The chromosomal region most frequently affected by losses of genomic material clustered on 13q (9/26). 6/7 myE showed a loss on 13q14-q31. Other chromosomes affected by genomic losses were 6q (5/26), 4q (5/26), 10 (5/26), and 2q (4/26). The most consistent chromosomal abnormality in ependymomas so far reported, is monosomy 22 or structural abnormality 22q, identified in approximately one third of Giemsabanded cases with abnormal karyotypes. Using FISH, loss or monosomy 22q was detected in small subpopulations of tumor cells in 36% of cases. The most frequent gains involved chromosome arms 17 (8/26), 9q (7/26), 20q (7/26), and 22q (6/26). Gains on 1q were found exclusively in pediatric ependymomas (5/10). Using FISH, MYCN proto-oncogene DNA amplifications mapped to 2p23-p24 were found in 2 spinal ependymomas of adults. On average, myE demonstrated 9.14, E 5.33, and aE 1.77 gains and/or losses on different chromosomes per tumor using CGH. Thus, and quite paradoxically, in ependymomas, a high frequency of imbalanced chromosomal regions as revealed by CGH does not indicate a high WHO grade of the tumor but is more frequent in grade I tumors. [source]


    Intraoperative diagnosis of tanycytic ependymoma: Pitfalls and differential diagnosis

    DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2001
    Marc A. Dvoracek M.D.
    Abstract Smear preparations have become increasingly popular in the intraoperative assessment of central nervous system pathology. The cytological features of a histologically proven tanycytic ependymoma are presented with the pitfalls and differential diagnosis. The smear preparation showed a glial neoplasm composed of cells with long, bipolar glial processes and oval to spindle-shaped nuclei resembling those seen in pilocytic astrocytoma smears. The smear characteristics of an ependymoma usually show remarkably uniform round-to-oval nuclei, fluffy glial processes, and a perivascular nuclear-free zone (pseudorosetting). None of these features were present in our case. The accompanying frozen section showed a fascicular spindle-cell tumor that resembled a schwanomma, a commonly reported misinterpretation of the histology of tanycytic ependymomas on frozen sections. Careful attention to the radiological findings, the surgeon's impression, and the intraoperative smear preparation details should allow one to include this uncommon entity in the differential diagnosis of spinal neoplasms. Diagn. Cytopathol. 24:289,292, 2001. © 2001 Wiley-Liss, Inc. [source]


    Cerebellar tumour presenting with pathological laughter and gelastic syncope

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2007
    G. Famularo
    There is no report of patients in whom pathological laughter, a rare condition characterized by uncontrollable episodes of laughter usually triggered by unrelated stimuli, was ever closely associated with a loss of consciousness overtly linked with the onset of such uncontrollable laughter, also referred to as a gelastic syncope. A 53-year-old man presented with a 4-month history of syncope following intense and uncoordinated laughter. Physical and neurological examination was normal and the patient had no other typical cerebellar signs. We found a mass in the cerebellar vermis abutting the floor of the fourth ventricle, which upon histological examination after surgery proved to be an ependymoma. We emphasize that pathological laughter and gelastic syncope could represent unique and sole features of a cerebellar disorder. [source]


    Localization of a putative low-penetrance ependymoma susceptibility locus to 22q11 using a chromosome 22 tiling-path genomic microarray

    GENES, CHROMOSOMES AND CANCER, Issue 4 2005
    Anneke C. J. Ammerlaan
    Ependymomas frequently display allelic loss of chromosome 22 in the absence of mutations in the known tumor-suppressor genes on chromosome 22, suggesting the role of an alternative predisposing gene or genes from this chromosome. In an effort to localize these genes, 37 ependymomas derived from 33 patients were analyzed for the presence of copy number changes by use of a high-resolution chromosome 22 genomic microarray. Eighteen ependymomas (49%) displayed an array-CGH profile consistent with monosomy of chromosome 22. However, in 10 of these tumors, the fluorescence ratios for 22q clones scored as deleted were different from those at the single gene copy level. This suggests either analysis of mixed populations of tumor and normal stromal cells or analysis of mixed tumor cell populations with different genetic profiles. Four ependymomas derived from two patients showed overlapping interstitial deletions of 2.2 Mb and ,510 kb. Further analyses revealed that these deletions were present in the constitutional DNA of these two patients as well as in some of their unaffected relatives. Detailed microsatellite analysis of these families refined the commonly deleted segment to a region of 320 kb between markers RH13801 and D22S419. Our results provide additional evidence for the involvement of genes on chromosome 22 in the development of ependymoma and suggest the presence of a low-penetrance ependymoma susceptibility locus at 22q11. © 2005 Wiley-Liss, Inc. [source]


    MicroRNA-10b is overexpressed in malignant glioma and associated with tumor invasive factors, uPAR and RhoC

    INTERNATIONAL JOURNAL OF CANCER, Issue 6 2009
    Takashi Sasayama
    Abstract MicroRNAs (miRNAs) are effective post-transcriptional regulators of gene expression and are important in many biological processes. Although the oncogenic and tumor suppressive functions of several miRNAs have been characterized, the role of miRNAs in mediating tumor invasion and migration remains largely unexplored. Recently, miR-10b was identified as an miRNA highly expressed in metastatic breast cancer, promoting cell migration and invasion. Here, we performed real-time reverse transcriptase polymerase chain reaction (RT-PCR) assays on 43 glioma samples (17 glioblastoma, 6 anaplastic astrocytoma, 10 low-grade astrocytoma, 6 oligodendroglioma and 4 ependymoma) and 6 glioma cell lines. We found that miR-10b expression was upregulated in all glioma samples compared to non-neoplastic brain tissues. The expression levels of miR-10b were associated with higher grade glioma. In addition, mRNA expressions of RhoC and urokinase-type plasminogen activator receptor (uPAR), which were thought to be regulated by miR-10b via HOXD10, were statistically significantly correlated with the expression of miR-10b (p < 0.001, p = 0.001, respectively). Also, protein expression levels of RhoC and uPAR were associated with expression levels of miR-10b (p = 0.009, p = 0.014, respectively). Finally, multifocal lesions on enhanced MRI of 7 malignant gliomas were associated with higher expression levels of miR-10b (p = 0.02). Our data indicated that miR-10b might play some role in the invasion of glioma cells. © 2009 UICC [source]


    Various components of the insulin-like growth factor system in tumor tissue, cerebrospinal fluid and peripheral blood of pediatric medulloblastoma and ependymoma patients

    INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008
    Judith M. de Bont
    Abstract The insulin-like growth factor (IGF) system plays an important role in neuronal development and may contribute to the development of brain tumors. In this study, we studied mRNA expression levels of IGFs, insulin-like growth factor binding proteins (IGFBPs) and insulin-like growth factor receptors (IGFRs) in 27 pediatric medulloblastomas, 13 pediatric ependymomas and 5 control cerebella. Compared to normal cerebellum, mRNA levels of IGFBP-2 and IGFBP-3 were significantly increased in medulloblastomas and ependymomas. IGFBP-2 expression was indicative of poor prognosis in medulloblastomas, whereas IGFBP-3 mRNA levels were especially high in anaplastic ependymomas. IGFBP-5 and IGF-II mRNA levels were significantly increased in ependymomas compared to control cerebellum. Protein expression levels of IGFs and IGFBPs were analyzed in the cerebrospinal fluid (CSF) of 16 medulloblastoma, 4 ependymoma and 23 control patients by radioimmuno assay to determine whether they could be used as markers for residual disease after surgery. No aberrant CSF protein expression levels were found for ependymoma patients. In medulloblastoma patients, the IGFBP-3 protein levels were significantly higher than in ependymoma patients and controls. Moreover, enhanced levels of proteolytic fragments of IGFBP-3 were found in the CSF of medulloblastoma patients, being in concordance with a significantly increased IGFBP-3 proteolytic activity in the CSF of these patients. In conclusion, our data suggest that the IGF system is of importance in pediatric medulloblastomas and ependymomas. Larger studies should be conducted to validate the predictive values of the levels of intact IGFBP-3 and proteolytic fragments in CSF in the follow-up of medulloblastomas. © 2008 Wiley-Liss, Inc. [source]


    EGFR tyrosine kinase inhibition radiosensitizes and induces apoptosis in malignant glioma and childhood ependymoma xenografts

    INTERNATIONAL JOURNAL OF CANCER, Issue 1 2008
    Birgit Geoerger
    Abstract Malignant gliomas and childhood ependymomas have a high rate of treatment failure. Epidermal growth factor receptor (EGFR) activation has been implicated in the tumorigenesis and radioresistance of many cancers, including brain tumors. Therefore, combining EGFR targeting with irradiation is a potentially attractive therapeutic option. We evaluated the tyrosine kinase inhibitor gefitinib for its antitumor activity and potential to radio-sensitize in vivo in two xenograft models: an EGFR amplified glioma and an EGFR expressing ependymoma, both derived from primary tumors. When administered at 100 mg/kg for 5 consecutive days, gefitinib-induced partial tumor regression in all treated EGFR amplified IGRG88 glioma xenografts. The addition of 1 Gy of irradiation prior to gefitinib administration resulted in 5 complete and 4 partial regressions for the 9 treated tumors as well as a significant tumor growth delay of 33 days for the combined treatment compared to 19 days for each therapy alone, suggesting additive antitumor activity. Tumor regression was associated with inhibition of AKT and MAPK pathways by gefitinib. In contrast, the ependymoma IGREP83 was sensitive to irradiation, but remained resistant to gefitinib. Combined treatment was associated with inhibition of radiation-induced MAPK phosphorylation and significant induction of apoptotic cell death though radiation-induced AKT phosphorylation was maintained. Depending on the scheduling of both therapies, a trend towards superior antitumor activity was observed with combined treatment. Thus, EGFR targeting through tyrosine kinase inhibition appears to be a promising new approach in the treatment of EGFR-driven glioma, particularly in combination with radiation therapy. © 2008 Wiley-Liss, Inc. [source]


    Liver grafts from donors with central nervous system tumors: A single-center perspective

    LIVER TRANSPLANTATION, Issue 10 2009
    Randeep Kashyap
    Traditionally, patients who die with a malignancy have been excluded from donation. However, it has become a common practice to accept organs from donors that have low-grade tumors or tumors with low metastatic potential. The aim of this study was to analyze our experience with the use of liver grafts from donors with central nervous system (CNS) tumors. A retrospective review of 1173 liver transplants performed between 1992 and 2006 identified 42 donors diagnosed with a CNS tumor. Thirty-two tumors were malignant, and 10 tumors were benign. Forty-two liver transplant recipients received livers from these donors. All patients were followed until May 2007 with a mean follow-up of 29 ± 17 months. Among 42 donors, there were 28 males and 14 females. The mean donor risk index was 1.78 ± 0.39. Twenty (47.6%) of the CNS tumors were glioblastoma multiforme (astrocytoma grade IV), 11 (26.2%) were other astrocytomas, and 1 (2.4%) was an anaplastic ependymoma. Twenty (62.5%) neoplasms were grade IV tumors, 8 (25%) were grade II tumors, and 4 (12.5%) were grade III tumors. Over 80% of the patients had at least 1 kind of invasive procedure violating the blood-brain barrier. The rate of recurrence for the entire group was 2.4% (all CNS tumors). There were 7 (7.2%) deaths in all. The most common cause of death was sepsis (n = 3, 7.2%). There was no difference in survival between recipients of grafts from donors with CNS tumors and recipients of grafts from donors without CNS tumors (1 year: 82% versus 83.3%, P = not significant; 3 years: 77.4% versus 72%, P = not significant). In conclusion, in our experience, despite violation of the blood-brain barrier and high-grade CNS tumors, recurrence was uncommon. Grafts from these donors are often an overlooked source of high-quality organs from younger donors and can be appropriately used, particularly in patients who, despite low Model for End-Stage Liver Disease scores, carry a high risk of mortality. Liver Transpl 15:1204,1208, 2009. © 2009 AASLD. [source]


    Bilateral Motor Cortex Stimulation for the Relief of Central Dysesthetic Pain and Intentional Tremor Secondary to Spinal Cord Surgery: A Case Report

    NEUROMODULATION, Issue 4 2002
    Roberto Fabian Rodríguez MD
    Abstract Objectives. Our objective was to describe and analyze through a third party disinterested observer the results obtained by using motor cortex stimulation (MCS) for the treatment of central dysesthetic diffuse-distal type of paraplegic pain and intentional tremor secondary to the total removal of a cervical ependymoma. Design. Retrospective case report with discussion. Methods. A 69-year-old female, who after satisfactory removal of a cervical ependymoma, developed a central dysesthetic diffuse-distal type of paraplegic pain and intentional tremor associated with mild cerebellar deficit. Neurologic compromise became so intense that it prevented the patient from leading an independent lifestyle. Conservative treatments failed and a unilateral trial of MCS was performed. After a four-day satisfactory unilateral trial, a bilateral electrode, Resume II (Medtronic, Inc., Minneapolis, MN), was inserted through a small craniotomy and a dual-channel RF activated receiver was implanted. During the second month of follow-up an independent observer personally interviewed the patient and assessed results through a multimodal approach, encompassing several analog scales used to measure the different components of the painful experience; a daily life activities scale and drug intake. Results. Evoked painful phenomena were dramatically improved, but the steady component of pain was only moderately relieved. The patient's tremor improved to allow for the performance of simple movements such as independent eating. Conclusion. In this single case report MCS was extremely useful in eliminating almost all of the patient's pain-evoked phenomena. Both steady burning pain and tremor were also improved. This is only one case report and MCS warrants further investigation as to its utility in controlling central dysesthetic pain in paraplegia and postchordotomy dysesthesias. [source]


    Pigmented ependymoma with signet-ring cells and Rosenthal fibers: A rare variant of ependymoma

    NEUROPATHOLOGY, Issue 1 2010
    Yesim Ertan
    We report a rare case of ependymoma with vacuolar features, signet cells, pigmentation and numerous Rosenthal fibers arising in the fourth ventricle of a 35-year-old woman. The tumor was composed of cells with cytoplasmic vacuoles, signet cells and clear cells. The clear cells were compactly arranged resembling oligodendroglioma. Pseudovascular and ependymal rosettes were observed only in focal areas. Additionally, some tumor cells contained brown cytoplasmic pigment, which was histochemically compatible with lipofuscin and neuromelanin. On immunohistochemical examination, the tumor cells were positive for S100, glial fibrillary acidic protein and vimentin, and negative for synaptophysin, cytokeratin, neurofilament and HMB45. Epithelial membrane antigen staining showed dot-like and small vesicular reactivity. The case is presented to increase familiarity with these extraordinary variants of ependymoma. [source]


    Malignant transformation of supratentorial clear cell ependymoma

    NEUROPATHOLOGY, Issue 3 2009
    Masanori Kurimoto
    Recurrence of clear cell ependymoma is not a rare condition, but malignant transformation of clear cell ependymoma has not yet been well presented. The authors report a 44-year-old man who presented with progressive right hemiparesis. A brain tumor in the left frontal premotor area was removed and an initial pathological diagnosis of oligodendroglioma was made. The tumor recurred 4 months later, and reoperation of the tumor and adjuvant local radiotherapy were performed. The patient subsequently underwent surgical removal of recurrent tumors on another four occasions (6 times in total) during a period of 11 years and finally died of the original disease. Histopathological studies of all surgical and autopsy specimens were carried out. The first and second surgical specimens did not contain any ependymal rosettes or pseudorosettes, and thus a diagnosis of oligodendroglioma was made. However, the third surgical specimen showed pseudorosettes. At this time, the tumor had an ultrastructural appearance compatible with ependymoma. Thereafter, the recurrent tumors showed anaplastic features such as nuclear pleomorphisms and necrosis with pseudopallisading. The autopsy specimens resembled a feature of glioblastoma but the tumor was sharply demarcated from the surrounding parenchyma. [source]


    Solitary subependymal giant cell astrocytoma incidentally found at autopsy in an elderly woman without tuberous sclerosis complex

    NEUROPATHOLOGY, Issue 2 2009
    Hidehiro Takei
    Subependymal giant cell astrocytoma (SEGA) is a benign, slowly growing tumor typically occurring in the setting of tuberous sclerosis complex (TSC). However there are several reported cases in which patients with a solitary SEGA had no other stigmata of TSC. We describe a case of SEGA in a 75-year-old woman representing the oldest patient reported to-date. The patient had a history of radical vulvectomy for malignant melanoma (MM), and died of autopsy-confirmed widespread systemic metastasis. Postmortem examination of the brain revealed a single 2.1 × 1.0 × 0.8 cm intraventricular nodule in the lateral ventricle. Histologically, it was composed of interlacing bundles of spindle-shaped tumor cells with thin delicate processes admixed with relatively large pleomorphic cells with abundant glassy eosinophilic cytoplasm, as seen in a SEGA. Immunohistochemically, GFAP, S-100 protein, and neuron specific enolase were positive, and synaptophysin labeled a few tumor cells. Also noted were rare isolated MM cells within the tumor (i.e., tumor-to-tumor metastasis). Autopsy showed no manifestations of TSC systemically or intracranially. The histopathological differential diagnosis was limited and included giant cell ependymoma and, much less likely, giant cell glioblastoma and pleomorphic xanthoastrocytoma. This case illustrates that SEGA can be found incidentally in an elderly individual with no associated symptoms and also indicates that SEGA can occur outside the setting of TSC. Tumor metastasis to an occult SEGA is extremely rare. [source]


    Clear cell ependymoma: a mimicker of oligodendroglioma , report of three cases

    NEUROPATHOLOGY, Issue 4 2008
    Deepali Jain
    Clear cell variant of ependymoma is a rare entity which morphologically mimics oligodendroglioma and poses a diagnostic dilemma. We describe three cases of clear cell ependymoma in male children which were supratentorial in location. On microscopic examination, these tumors were composed of sheets of clear cells and resembled oligodendroglioma. Electron microscopy confirmed the ependymal nature of these tumors. Clear cell ependymomas are rare and aggressive tumors. More cases need to be reported to determine their therapeutic responsiveness and prognosis. [source]


    Highly cystic brain tumor: Rare histological features in an ependymoma

    NEUROPATHOLOGY, Issue 4 2007
    Dorel Arsene
    Ependymoma is a slowly growing tumor appearing mostly in children and young adults. Several histological patterns are described. We report a case with unusual microscopic features, composed mostly of multiple cysts. Ultrastructural and immunohistochemical examination confirmed the diagnosis. Neuropathologists should be aware of this particular change which can generate some diagnostic difficulties. [source]


    Clear cell ependymoma of the fourth ventricle

    NEUROPATHOLOGY, Issue 4 2004
    Masahito Katoh
    Two cases of clear cell ependymoma (CCE) of the fourth ventricle are reported in a 49-year-old woman with dysphagia and a 59-year-old woman with dizziness and gait disturbance. CCE is a relatively new variant of ependymoma added to the WHO classification of tumors in 1993. Tumor cells display an oligodendroglioma-like appearance with a clear perinuclear halo. Most infratentorial CCE tumors are located in the cerebellum. There are only three cases, including the present two cases, that have been reported to affect the fourth ventricle. [source]


    Membranous expression of glucose transporter-1 protein (GLUT-1) in embryonal neoplasms of the central nervous system

    NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 1 2000
    M. Loda
    The human erythrocyte GLUT-1 is a transmembrane protein which facilitates transport of glucose in the cell in an energy-independent fashion. Neuroectodermal stem cells show strong membrane immunoreactivitry with this marker at early developmental stages in rodents. Membranous expression by undifferentiated neuroectodermal cells gradually decreases while GLUT-1 becomes confined to the endothelial cells, when these acquire blood,brain barrier function. We thus sought to determine whether GLUT-1 expression was limited to embryonal neoplasms of the central nervous system (CNS) which are presumably derived from developmentally arrested neuroectodermal stem cells. Archival material of 40 primary CNS neoplasms were examined for immunoreactivity with anti-GLUT-1. This included both non-embryonal neoplasms (18 astrocytic tumours, one ependymoma and three oligodendroglioma) and embryonal neoplasms (12 cerebellar medulloblastomas, four supratentorial PNETs and two atypical teratoid/rhabdoid tumours (AT/RhT)). In addition, cell lines and nude mice xenografts derived from both undifferentiated and differentiated tumours were assessed for GLUT-1 immunoreactivity by both immunohistochemistry and Western blotting. All embryonal tumours, MBs and PNET xenografts consistently showed GLUT-1 membrane staining. Non-embryonal neoplasms were negative except for vascular staining. Membrane protein fraction of embryonal tumours cell lines immunoreacted by immunoblot with GLUT-1, whereas the glioblastoma cell line was negative. Expression of GLUT-1 supports the stem cell nature of the cells of origin of MBs, supratentorial PNET and AT/RhTs. As a result, GLUT-1 is a useful marker to define the embryonal nature of CNS neoplasms. [source]


    Adjuvant radiotherapy in the treatment of pediatric myxopapillary ependymomas,,

    PEDIATRIC BLOOD & CANCER, Issue 4 2010
    Hani Al-Halabi MD
    Abstract Objectives Assess the role of radiotherapy (RT) in the management of primary and recurrent myxopapillary ependymoma (MPE). Materials and Methods We conducted a retrospective review of patients with MPE treated at the Montreal Children's Hospital/McGill University Health Centre between 1985 and 2008. Results Seven children under the age of 18 were diagnosed and treated for MPE. All patients were treated with surgery to the primary site. Three patients underwent subtotal resection (STR) and received adjuvant post-operative RT. Only one patient who had spinal drop metastases received post-operative RT to the lumbosacral region following complete resection of the primary tumor. After a median follow up of 78 months (range 24,180 months), all patients were alive with controlled disease. The single patient treated with gross total resection (GTR) and adjuvant local radiation remained recurrence free. One of the three patients treated with STR and adjuvant RT had disease progression that was controlled with re-resection and further RT. Two of the three patients treated with surgery alone developed local and disseminated recurrent spinal disease that was controlled by salvage RT. Conclusion Our data support the evolving literature which suggests that GTR alone provides suboptimal disease control in MPE. In our patients, RT resulted in control of residual, metastatic and/or recurrent disease. Routine adjuvant RT may improve outcomes in pediatric MPE. Pediatr Blood Cancer. 2010;55:639,643. © 2010 Wiley-Liss, Inc. [source]


    Maximally safe resection followed by hypofractionated re-irradiation for locally recurrent ependymoma in children

    PEDIATRIC BLOOD & CANCER, Issue 7 2009
    Arthur K. Liu MD
    Abstract Background Treatment failure in children with ependymoma is relatively common, with the majority of events consisting of local failure. Salvage therapy for these children historically had poor results, with repeated local recurrences. To improve these outcomes, we began to offer hypofractionated re-irradiation after resection at first local recurrence. To minimize the duration of therapy, we chose a hypofractionated regimen that has been shown to be well tolerated in adult patients. Procedure We performed a review of the experience at the Children's Hospital in Denver and at the Department of Radiation Oncology at the University of Colorado Denver from 1995 to 2008 with hypofractionated re-irradiation after maximally safe resection in children with locally recurrent ependymoma. Results Six children with locally recurrent ependymoma were seen in that time period. After maximally safe resection, all six received hypofractionated radiation therapy of 24,30 Gy delivered in three fractions. With a median follow-up of 28 months from the time of re-irradiation, all six children are alive with no evidence of disease. Three children had evidence of radiation necrosis, either clinically or based on imaging, but none required significant intervention. Conclusions Hypofractionated re-irradiation after resection for locally recurrent ependymoma is well tolerated. This approach also appears to provide good local control. Additional follow-up is required to determine the efficacy and potential late effects of hypofractionated re-irradiation in this patient population. Pediatr Blood Cancer 2009;52:804,807. © 2009 Wiley-Liss, Inc. [source]


    The pediatric preclinical testing program: Description of models and early testing results,

    PEDIATRIC BLOOD & CANCER, Issue 7 2007
    Peter J. Houghton PhD
    Abstract Background The Pediatric Preclinical Testing Program (PPTP) is an initiative supported by the National Cancer Institute (NCI) to identify novel therapeutic agents that may have significant activity against childhood cancers. The PPTP has established panels of childhood cancer xenografts and cell lines to be used for in vivo and in vitro testing. These include panels for Wilms tumor, sarcomas (rhabdomyosarcoma, Ewing sarcoma, and osteosarcoma), neuroblastoma, brain tumors (glioblastoma, ependymoma, and medulloblastoma), rhabdoid tumors (CNS and renal), and acute lymphoblastic leukemia (ALL). Here, we describe the characteristics of the in vivo tumor panels and report results for the in vivo evaluation of two standard agents, vincristine and cyclophosphamide. Procedures Solid tumors were grown subcutaneously in immune-deficient mice and tumor dimensions were measured weekly. ALL xenografts were inoculated intravenously and human CD45-positive cells were enumerated weekly. Results Vincristine-induced objective responses in 6 of 24 (25%) and cyclophosphamide-induced objective responses in 18 of 28 (64%) solid tumor models. Comparable assessments of high levels of activity for these two agents were obtained using a tumor growth delay (TGD) measure. Both agents induced regressions in each of the ALL models evaluated. Conclusions We have established 51 solid tumor and 10 ALL in vivo models. The models identify vincristine and cyclophosphamide as having broad-spectrum activity. The PPTP tumor panels appear to generally recapitulate the activity of these agents against specific childhood cancers and to have the potential for identifying novel agents having significant clinical activity. Pediatr Blood Cancer 2007;49:928,940. Published 2006 Wiley-Liss, Inc. [source]


    CSF cytology has limited value in the evaluation of patients with ependymoma who have MRI evidence of metastasis,

    PEDIATRIC BLOOD & CANCER, Issue 2 2006
    Igor M. Poltinnikov MD
    Abstract Purpose To investigate the usefulness of cerebrospinal fluid (CSF) cytology in pediatric patients with ependymoma who relapsed after focal irradiation. Methods Eighty-eight patients with ependymoma received conformal radiotherapy (CRT) from July 1997 through January 2003 on an IRB approved prospective treatment protocol. CSF cytology results from evaluations performed prior to CRT and at the time of failure were reviewed for patients who progressed after CRT as documented by magnetic resonance imaging (MRI). Results Twenty-two patients had MRI documented evidence of progression after CRT. Ten patients developed distant failure without local failure, four had combined local and distant failure and eight had local failure without distant failure. The median time from the start of CRT to progression was 19 months (range: 6,73). CSF cytology at diagnosis was negative for the presence of malignant cells in all patients. At the time of progression, CSF cytology was performed in 16 of 22 patients including all 10 patients with distant failure without local recurrence. Malignant cells were not found in any of the evaluated CSF specimens including those with distant failure documented by MRI. Conclusions CSF cytology does not add valuable information when evaluating patients with ependymoma who have evidence of distant failure documented by MRI. The usefulness of CSF cytology in the general follow-up evaluation of pediatric patients with ependymoma remains uncertain. © 2005 Wiley-Liss, Inc. [source]


    A phase I study of irinotecan administered on a weekly schedule in pediatric patients

    PEDIATRIC BLOOD & CANCER, Issue 1 2006
    L. Bomgaars MD
    Abstract Background The objectives of this study were to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and anti-tumor effect of irinotecan in pediatric patients with recurrent or refractory malignancies. Procedure Twenty-three patients between 1 and 21 years of age, with a solid tumor refractory to standard therapy or for which there was no standard therapy were enrolled. Irinotecan was administered over 90 min weekly 4×, every 6 weeks. The initial dose level was 125 mg/m2/day, with subsequent escalations to 160 and 200 mg/m2/day. A MTD was defined in heavily-pretreated and less-heavily-pretreated (,2 prior chemotherapy regimens, no prior bone marrow transplantation, and no central axis radiation) patients. Pharmacokinetic studies were also performed. Results Neutropenia and diarrhea were the DLTs in heavily pretreated patients; the MTD was 125 mg/m2/day. Neutropenia was the DLT in less-heavily pretreated; the MTD was 160 mg/m2/day. Five patients had stable disease for two to four cycles including one patient each with rhabdomyosarcoma, Ewing sarcoma, neuroblastoma, and two patients with ependymoma. Irinotecan clearance was greater that that previously reported for children receiving high dose irinotecan. Conclusions The recommended phase II dose of irinotecan administered weekly 4×, every 6 weeks in children with solid tumors is 125 mg/m2/dose for heavily pretreated patients and 160 mg/m2/dose for less heavily pretreated patients. © 2005 Wiley-Liss, Inc. [source]


    Surgical and radiotherapy treatment of a spinal cord ependymoma in a dog

    AUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2006
    H. UENO
    A 4-year-old Beagle dog was presented for investigation of a left pelvic limb gait abnormality. Neurolocalisation indicated a lumbar (L2 to L5) spinal cord lesion. On magnetic resonance imaging (MRI), an intramedullary mass was demonstrated at L3. The mass was partially removed under general anaesthesia and a diagnosis of ependymoma was made on histological examination. The dog was treated with postoperative orthovoltage x-ray radiation (total dose; 44 Gy given in 11 fractions over a 4 week period) combined with low dose carbo-platin (25 mg/m2). The dog was alive 16 months after surgery without further neurological deficits. No further tumour growth was detected on subsequent MRI evaluations. [source]


    Telomerase Inhibition as a Novel Therapy for Pediatric Ependymoma

    BRAIN PATHOLOGY, Issue 4 2010
    Vincent C.H. Wong
    Abstract Ependymomas are the third most common pediatric brain tumor with an overall survival of ,50%. Recently, we showed that telomerase [human telomerase reverse transcriptase (hTERT)] expression is a predictor of poor outcome in pediatric ependymoma. Thus, we hypothesized that ependymomas with functional telomerase may behave more aggressively and that these patients may benefit from anti-telomerase therapy. To address our hypothesis, we investigated the effect of telomerase inhibition on primary ependymoma cells harvested at the time of surgery, as no animal models or established cell lines are readily available for this tumor. The cells were characterized for glial fibrillary acidic protein (GFAP) and hTERT expression, initial telomere length and telomerase activity. They were then subjected to telomerase inhibition (MST-312, 1 µM) and tested for effects on cell viability (MTT assay), proliferation (MIB-1), apoptosis (cleaved caspase 3) and DNA damage (,H2AX). After 72 h of telomerase inhibition, primary ependymoma cells showed a significant decrease in cell number (P < 0.001), accompanied by increased DNA damage (,H2AX expression) (P < 0.01) and decreased proliferative index (MIB-1) (P < 0.01). Half showed an increase in apoptosis (cleaved caspase 3). These data suggest that telomerase inhibition may be an effective adjuvant therapy in pediatric ependymoma, potentially inducing tumor growth arrest in the short term, independent of telomere shortening. [source]


    Unique Molecular Characteristics of Pediatric Myxopapillary Ependymoma

    BRAIN PATHOLOGY, Issue 3 2010
    Valerie N. Barton
    Abstract Myxopapillary ependymoma (MEPN) generally can be cured by gross total surgical resection and usually manifest a favorable prognosis. However, surgery is less curative in tumors that are large, multifocal or extend outside the thecal sac. Late recurrences may occur, particularly in pediatric patients. The role of adjuvant therapy is unclear in the clinical management of recurrent tumors. Clinical trial design requires a better understanding of tumor biology. Unique molecular features of MEPN were investigated by using microarray technology to compare the gene expression of five pediatric MEPN to 24 pediatric intracranial ependymoma (EPN). The upregulation of three genes of interest, homeobox B13 (HOXB13), neurofilament, light polypeptide (NEFL) and PDGFR,, was further studied by immunohistochemistry in a larger cohort that included adult MEPN and EPN specimens. Protein expression in MEPN was compared to subependymoma, spinal EPN, intracranial EPN and normal fetal and adult ependyma. Immunoreactivity for HOXB13, NEFL and PDGFR, was strongest in MEPN and virtually absent in subependymoma. Spinal and intracranial EPN generally expressed weak or focal staining. MEPN manifests unique gene and protein expression patterns compared to other EPNs. Aberrant expression of HOXB13 suggests possible recapitulation of developmental pathways in MEPN tumorigenesis. PDGFR, may be a potential therapeutic target in recurrent MEPN. [source]


    Astroblastoma: Clinicopathologic Features and Chromosomal Abnormalities Defined by Comparative Genomic Hybridization

    BRAIN PATHOLOGY, Issue 3 2000
    Daniel J. Brat M.D., Ph.D.
    Astroblastomas are uncommon brain tumors whose classification and histogenesis have been debated. Precise criteria for diagnosis have been described only recently, but have not found wide acceptance. We report the clinical, radiographic, and histopathologic features of 20 astroblastomas, and the chromosomal alterations in seven cases as detected by comparative genomic hybridization (CGH). The tumors occurred both in children and young adults (average age, 14 years), most often as well circumscribed, peripheral, cerebral hemispheric masses. Radiographically, the lesions were contrastenhancing and solid, often with a cystic component. All were characterized histologically by astroblastic pseudorosettes, and most displayed prominent perivascular hyalinization, regional hyaline changes, and pushing borders in regard to adjacent brain. Tumor cells were strongly immunoreactive for S-100 protein, GFAP, and vimentin. Staining for EMA was focal. Ten of 20 astroblastomas were classified as "well differentiated" and 10 were classified as "malignant," largely on the basis of hypercellular zones with increased mitotic indices, vascular proliferation, and necrosis with pseudopalisading. All 10 well differentiated lesions and 8 of 10 malignant lesions were completely resected. None of the well differentiated astroblastomas recurred within the limited follow-up period. Three malignant astroblastomas recurred, including two incompletely resected tumors, and one that had been totally resected. One patient died of disease following recurrence. The most frequent chromosomal alterations detected by CGH were gains of chromosome arm 20q (4/7 tumors) and chromosome 19 (3/7). The combination of these gains occurred in three, including two well differentiated and one malignant astroblastoma. Other alterations noted in two tumors each were losses on 9q, 10, and X. These chromosomal alterations are not typical of ependymoma or infiltrating astrocytic neoplasms, and suggest that astroblastomas may have a characteristic cytogenetic profile in addition to their distinctive clinical, radiographic, and histopathologic features. [source]