====== Ependymoma RELA fusion positive ======
[[Ependymoma]] [[RELA fusion]]-positive is a accepted variant of ependymoma, only recognised in the [[World Health Organization Classification of Tumors of the Central Nervous System 2016]]
((Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D,
Cavenee WK, Ohgaki H, Wiestler OD, Kleihues P, Ellison DW. The 2016 World Health 
Organization Classification of Tumors of the Central Nervous System: a summary.
Acta Neuropathol. 2016 Jun;131(6):803-20. doi: 10.1007/s00401-016-1545-1. Epub
2016 May 9. Review. PubMed PMID: 27157931.
)).

===== Epidemiology =====
These tumors may account for 70% of [[supratentorial ependymoma]]s in children and represent an aggressive entity distinct from other ependymomas.

Not found in the [[posterior fossa]] or [[spinal cord]]. 


Two-thirds of supratentorial (ST) ependymomas harbor oncogenic fusions of RELA.

====Outcome====
The protein product is the principal effector of canonical [[Nuclear factor kappa]] signaling. RELA fusion proteins activate signaling for tumor proliferation and malignant progression, resulting in poorer prognoses in these patients compared to those in patients with other ST ependymomas. 

In a study, Nakamura et al. encountered a case of [[C11orf]]-RelA fusion-positive ST anaplastic ependymoma that was diagnosed in first tumor resection surgery of multi-staged gross total resection with molecular evidence. In ependymomas, regardless of tumor location or pathological grade, subtotal resection is associated with higher rates of mortality compared with GTR
((Nakamura T, Fukuoka K, Ikeda J, Yoshitomi M, Udaka N, Tanoshima R, Tateishi K,
Yamanaka S, Ichimura K, Yamamoto T. Encouraging option of multi-staged gross
total resection for a C11orf-RelA fusion-positive supratentorial anaplastic
ependymoma. Brain Tumor Pathol. 2017 Oct;34(4):160-164. doi:
10.1007/s10014-017-0297-5. Epub 2017 Aug 22. PubMed PMID: 28831588.
)).

In [[posterior fossa ependymoma]] group A (PF-EPN-A) tumors, [[telomerase]] activity varied and was significantly associated with dismal [[overall survival]], whereas telomerase reactivation was present in all supratentorial RelA fusion-positive (ST-EPN-RELA) ependymomas
((Gojo J, Lötsch D, Spiegl-Kreinecker S, Pajtler KW, Neumayer K, Korbel P, Araki
A, Brandstetter A, Mohr T, Hovestadt V, Chavez L, Kirchhofer D, Ricken G,
Stefanits H, Korshunov A, Pfister SM, Dieckmann K, Azizi AA, Czech T, Filipits M,
Kool M, Peyrl A, Slavc I, Berger W, Haberler C. Telomerase activation in
posterior fossa group A ependymomas is associated with dismal prognosis and
chromosome 1q gain. Neuro Oncol. 2017 Sep 1;19(9):1183-1194. doi:
10.1093/neuonc/nox027. PubMed PMID: 28371821; PubMed Central PMCID: PMC5570194.
)).

====Pathology====

These tumours can be both grade II or III and demonstrate a variety of histological morphologies, although clear cells and prominent vascularity are common.

The presence of the RELA fusion gene can be assessed with FISH. 

====Immunophenotype====

[[GFAP]] positive
    
[[EMA]] positive
    
[[L1CAM]] positive correlates closely with the presence of RELA fusion not exclusive to ependymomas.

====Treatment====
[[Actinomycin D]] could constitute a promising therapeutic option for [[Ependymoma RELA fusion positive]], whose tumours frequently exhibit [[p53]] inactivation
((Tzaridis T, Milde T, Pajtler KW, Bender S, Jones DT, Müller S, Wittmann A,
Schlotter M, Kulozik AE, Lichter P, Peter Collins V, Witt O, Kool M, Korshunov A,
Pfister SM, Witt H. Low-dose Actinomycin-D treatment re-establishes the
tumoursuppressive function of P53 in RELA-positive ependymoma. Oncotarget. 2016
Sep 20;7(38):61860-61873. doi: 10.18632/oncotarget.11452. PubMed PMID: 27556362; 
PubMed Central PMCID: PMC5308696.
)).

Intraoperative [[MR perfusion imaging]] may be a useful method for delineating tumor [[aggressiveness]] and borders, which can be prognostic
((Gamboa NT, Karsy M, Gamboa JT, Yoon NK, Driscoll MJ, Sonnen JA, Salzman KL,
Jensen RL. Preoperative and intraoperative perfusion magnetic resonance imaging
in a RELA fusion-positive anaplastic ependymoma: A case report. Surg Neurol Int. 
2018 Jul 24;9:144. doi: 10.4103/sni.sni_116_18. eCollection 2018. PubMed PMID:
30105138; PubMed Central PMCID: PMC6069373.)).

===== Case reports =====

Gamboa et al. from the Clinical Neurosciences Center, University of [[Utah]], [[Salt Lake City]], present the case of a patient with RELA-fusion positive ependymoma of the [[frontal lobe]] in whom they used preoperative and intraoperative [[MR perfusion imaging]]. In this first demonstrated intraoperative evaluation of [[MR perfusion]] in ependymoma, increased peripheral [[perfusion]] of the lesion in a ring-like manner with a discrete cutoff around the surgical margin correlated with intraoperative findings of a clear border between the tumor and brain, as well as pathological findings of increased [[MIB]] index and hypercellularity-specifically within solid tumor components. An abnormal perfusion pattern also suggested an aggressive lesion, which was later confirmed on pathological analysis. In addition, intraoperative MR perfusion improved detection of tumor tissue in combination with traditional T1-weighted contrast-enhanced methods, which increased extent of resection.

MR perfusion imaging may be a useful method for delineating tumor aggressiveness and borders, which can be prognostic
((Gamboa NT, Karsy M, Gamboa JT, Yoon NK, Driscoll MJ, Sonnen JA, Salzman KL,
Jensen RL. Preoperative and intraoperative perfusion magnetic resonance imaging
in a RELA fusion-positive anaplastic ependymoma: A case report. Surg Neurol Int. 
2018 Jul 24;9:144. doi: 10.4103/sni.sni_116_18. eCollection 2018. PubMed PMID:
30105138; PubMed Central PMCID: PMC6069373.)).

===2017===
A case of aggressive [[anaplastic ependymoma]] arising in the right frontoparietal lobe, which had genetically 1q25 gain, CDKN2A homozygous deletion, and L1CAM overexpression. The patient was a 10-year-old boy who underwent four times of tumor removal and seven times of gamma knife surgery. Metastatic loci were scalp and temporalis muscle overlying primary operation site, lung, liver, buttock, bone, and mediastinal lymph nodes. He had the malignancy for 10 years and died. This tumor is a representative case of [[Ependymoma RELA fusion positive]], showing aggressive behavior
((Kim SI, Lee Y, Kim SK, Kang HJ, Park SH. Aggressive Supratentorial Ependymoma,
RELA Fusion-Positive with Extracranial Metastasis: A Case Report. J Pathol Transl
Med. 2017 Nov;51(6):588-593. doi: 10.4132/jptm.2017.08.10. Epub 2017 Nov 15.
PubMed PMID: 29161788.
)).