====== Intracranial ependymoma ====== Intracranial [[ependymoma]], are believed to arise from trapping of embryonic rests of [[ependyma]]l tissue in the developing [[brain parenchyma]] ((Koeller KK, Sandberg GD; Armed Forces Institute of Pathology. From the archives of the AFIP. Cerebral intraventricular neoplasms: radiologic-pathologic correlation. Radiographics. 2002 Nov-Dec;22(6):1473-505. Review. PubMed PMID: 12432118. )). ===== Epidemiology ===== They constitute 2 to 9% of all [[intracranial tumor]]s and up to 12% of pediatric brain tumors. It is the third most common [[intracranial]] [[glioma]] in children. At least half of ependymomas present in the first two decades of life. Ependymal tumors in adults are rare, accounting for less than 4 % of primary tumors of the central nervous system in this age group. ---- The majority of [[intracranial ependymoma]]s (60%) are located in the [[posterior fossa]] ([[infratentorial]]), usually arising from the [[lateral recess]] of the [[fourth ventricle]] (molecular subgroup: [[Posterior fossa type A Ependymoma]]) and midline inferior floor of the [[fourth ventricle]] near the [[obex]] (molecular subgroup: Posterior Fossa B) ((Koeller KK, Sandberg GD. From the archives of the AFIP. Cerebral intraventricular neoplasms: radiologic-pathologic correlation. Radiographics. 22 (6): 1473-505. doi:10.1148/rg.226025118)) ((Yuh EL, Barkovich AJ, Gupta N. Imaging of ependymomas: MRI and CT. Childs Nerv Syst. 2009;25 (10): 1203-13. doi:10.1007/s00381-009-0878-7)) ((Smith A, Smirniotopoulos J, Horkanyne-Szakaly I. From the Radiologic Pathology Archives: Intraventricular Neoplasms: Radiologic-Pathologic Correlation. Radiographics. 2013;33 (1): 21-43. Radiographics (full text) - doi:10.1148/rg.331125192)) ((AlRayahi J, Zapotocky M, Ramaswamy V, Hanagandi P, Branson H, Mubarak W, Raybaud C, Laughlin S. Pediatric Brain Tumor Genetics: What Radiologists Need to Know. (2018) Radiographics : a review publication of the Radiological Society of North America, Inc. 38 (7): 2102-2122. doi:10.1148/rg.2018180109 - )) The remainder (40%) are located supratentorially and up to half of these are intraparenchymal. ===== Classification ===== [[Intracranial ependymoma classification]]. ===== Pathogenesis ===== Loss of [[chromosome 22]] and gain of 1q are the most frequent genomic aberrations in [[ependymoma]]s, indicating that genes mapping to these regions are critical in their pathogenesis. Using real-time quantitative PCR, Karakoula et al. measured relative copy numbers of 10 genes mapping to 22q12.3-q13.33 and 10 genes at 1q21-32 in a series of 47 pediatric [[intracranial ependymoma]]s. Loss of one or more of the genes on 22 was detected in 81% of cases, with [[RAC2]] and C22ORF2 at 22q12-q13.1 being deleted most frequently in 38% and 32% of ependymoma samples, respectively. Combined analysis of quantitative-PCR with methylation-specific PCR and bisulphite sequencing revealed a high rate (>60% ependymoma) of transcriptional inactivation of C22ORF2, indicating its potential importance in the development of pediatric ependymomas. Increase of relative copy numbers of at least one gene on 1q were detected in 61% of cases, with TPR at 1q25 displaying relative copy number gains in 38% of cases. Patient age was identified as a significant adverse prognostic factor, as a significantly shorter overall survival time (P = 0.0056) was observed in patients <2 years of age compared with patients who were >2 years of age. Loss of RAC2 at 22q13 or amplification of TPR at 1q25 was significantly associated with shorter overall survival in these younger patients (P = 0.0492 and P = < 0.0001, respectively). This study identifies candidate target genes within 1q and 22q that are potentially important in the pathogenesis of intracranial pediatric ependymomas ((Karakoula K, Suarez-Merino B, Ward S, Phipps KP, Harkness W, Hayward R, Thompson D, Jacques TS, Harding B, Beck J, Thomas DG, Warr TJ. Real-time quantitative PCR analysis of pediatric ependymomas identifies novel candidate genes including TPR at 1q25 and CHIBBY at 22q12-q13. Genes Chromosomes Cancer. 2008 Nov;47(11):1005-22. doi: 10.1002/gcc.20607. PubMed PMID: 18663750. )). ===== Clinical features ===== [[Intracranial ependymoma clinical features]] ===== Diagnosis ===== [[Intracranial ependymoma diagnosis]]. ===== Treatment ===== see [[Intracranial ependymoma treatment]]. ===== Outcome ===== [[Intracranial ependymoma outcome]]. ===== Case series ===== see [[Intracranial ependymoma case series]]. ===== References =====