(2000b). High mutant allele fractions have been found in patient samples at diagnosis and recurrence in tumor evolution studies. Pathology Outlines - Olig2 Accordingly, the treatment approach is tailored according to the presence of 1p19q co-deletion, which characterizes oligodendrogliomas. J. Neurooncol. Maruno, M., Yoshimine, T., Muhammad, A. G., Tokiyoshi, K., and Hayakawa, T. (1996). doi: 10.1200/jco.2003.06.023. Stephen A Berman, MD, PhD, MBA Professor of Neurology, University of Central Florida College of Medicine Targeting the RTK-PI3K-mTOR axis in malignant glioma: overcoming resistance. xref (2006). 2005 Jun. doi: 10.1227/neu.0b013e31820c3419, Soffietti, R., Rud, R., Bradac, G. B., and Schiffer, D. (1998). Mod. Oncol. Computed tomography scan of a low-grade oligodendroglioma. Afterward in 2001, Chinot et al. 112, 801809. UpToDate This content does not have an Arabic version. (2013b). Suzuki SO, Kitai R, Llena J, Lee SC, Goldman JE, Shafit-Zagardo B (May 2002). Patients with low-grade gliomas can be conventionally stratified into high risk and low risk categories, with risk referring to risk of tumor progression or recurrence. Cancer 91, 417422. (2012). Oligodendrogliomas occur more often in males and are rare in children. Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. PLoS One 11:e0163067. Roger E McLendon, MD Professor, Director of Surgical Pathology, Chief of Neuropathology, Department of Pathology, Duke University Medical Center About 1,000 oligodendrogliomas are diagnosed per year in the United States. The growth of cells, called a tumor, begins in cells called oligodendrocytes. (2019). 0000230580 00000 n Jorge C Kattah, MD is a member of the following medical societies: American Academy of Neurology, American Neurological Association, New York Academy of SciencesDisclosure: Nothing to disclose. (2017). Oligodendroglioma with ganglioglioma-like maturation: the histopathological diagnostic challenge of a brain neoplasm with aberrant neuronal component - A case report and review of the literature. Each stratum has different combination treatments and targeted patient populations. %PDF-1.4 % 61(9):1862-6. 0000245213 00000 n doi: 10.1212/wnl.51.4.1140, van den Bent, M., Taphoorn, M., Brandes, A., Menten, J., Stupp, R., Frenay, M., et al. A feature of oligodendroglioma that can be assessed on CT, as well as on MRI, is the typical location of the lesion. Appropriate design of future clinical trials can help in determining better correlations with molecular subclasses. Phase III trial of chemoradiotherapy for anaplastic oligodendroglioma: long-term results of RTOG 9402. NOA-04 randomized phase III trial of sequential radiochemotherapy of anaplastic glioma with procarbazine, lomustine, and vincristine or temozolomide. Few neural tumours have round nuclei - DDx in intraoperative specimen: High mitotic rate (6 or more mitoses/10 HPF of 0.55mm). 123, 853860. Neurology 51, 11401145. MB drafted the manuscript and contributed to the discussion section. However, in those groups with IDH mutations, including AO, TERT promoter mutation status was not a statistically significant prognostic factor (Dahlin et al., 2016). [QxMD MEDLINE Link]. Insulator dysfunction and oncogene activation in IDH mutant gliomas. Correlations Between O6-Methylguanine DNA Methyltransferase Promoter Methylation Status, 1p and 19q Deletions, and Response to Temozolomide in Anaplastic and Recurrent Oligodendroglioma: A. J. Clin. One way to do this is called awake brain surgery. With almost 12 years of follow-up, patients harboring tumors with 1p19q co-deletions showed an improved survival when treated with PCV and RT as compared to RT alone (EORTC26951: 157 vs. 50 months; RTOG9402: 14.7 vs. 7.3 years). New York: Churchill Livingstone; 1995. Lastly, it is worth noting that there are approximately 230 other clinical trials which involve oligodendrogliomas but are not actively recruiting patients. 40, 205216. 2-HG can inhibit alpha-KG dependent dioxygenases and cause epigenetic alterations (Xu et al., 2011). "Oligodendroglial-specific transcriptional factor SOX10 is ubiquitously expressed in human gliomas.". Oncol. Molecular alterations associated with tumor progression: Glioma CpG island methylator phenotype (G CIMP) (. This previously diagnosed oligoastrocytoma,, For unequivocal assessment of 1p/19q codeletion in oligodendroglial tumors, detection of whole-arm losses, MeSH 10, 139144. However, a clear distinction of both grades is not always possible. 9, 314318. Special tests can show detailed information about the tumor cells. 2006. Cancer-associated IDH1 mutations produce 2-hydroxyglutarate Dang L, White DW, Gross S, et al. J. Clin. In a recent case report by Yu et al. "ATRX and IDH1-R132H immunohistochemistry with subsequent copy number analysis and IDH sequencing as a basis for an "integrated" diagnostic approach for adult astrocytoma, oligodendroglioma and glioblastoma.". Some oligodendrogliomas have eosinophilic cytoplasm with focal perinuclear clearing. (2013). Variation in Olig2 gene is associated with psychosis in Alzheimer's disease ( Neurosci Lett 2009;461:54) Uses by pathologists May differentiate oligodendroglioma (Olig2+) from extraventricular neurocytoma (Olig2-, Brain Tumor Pathol 2011;28:157) Microscopic (histologic) images Images hosted on other servers: Pediatric glioblastoma 479-91. This in turn provides evidence that IDH mutations could allow cells to remain in a vulnerable state, and prone to additional DNA alterations. 19, 55135522. Brain, frontal lobe, left, tumor, resection. Grade III oligodendroglioma show a worse prognosis than grade II tumors due to the presence of anaplastic features such as nuclear atypia, necrosis, microvascular proliferation, high cell density and number of mitotic figures. 131, 803820. 2008 May. Intravenous carboplatin for recurrent malignant glioma: a phase II study. We welcome suggestions or questions about using the website. have a. Cairncross, G., Macdonald, D., Ludwin, S., Lee, D., Cascino, T., Buckner, J., et al. Epilepsia 44, 822830. 2003 Jul 1. Analysis from the initial study design. 0000003153 00000 n Tambi Jarmi, MD Resident Physician, Department of Internal Medicine, Carraway Methodist Medical Center 0000013354 00000 n Oligodendrogliomas are usually tumors of middle-aged adults, occurring most commonly in the 4 th and 5 th decades of life, somewhat older for grade 3 tumors 10,11. 0000014853 00000 n Brown R, Zlatescu M, Sijben A, Roldan G, Easaw J, Forsyth P. The use of magnetic resonance imaging to noninvasively detect genetic signatures in oligodendroglioma. Glioma-derived mutations in IDH1 dominantly inhibit IDH1 catalytic activity and induce HIF-1. For nearly a century, the diagnosis and grading of oligodendrogliomas and oligoastrocytomas has been based on histopathology alone. However, we cannot answer medical or research questions or give advice. Treatment of recurrent malignant supratentorial gliomas with carboplatin (CBDCA). 20 (8):2076-84. Neurology 46, 203207. Neuro Oncol. Accessed Sept. 26, 2022. Contributed by Jared T. Ahrendsen, M.D., Ph.D. and John DeWitt, M.D., Ph.D. Dubbink HJ, Atmodimedjo PN, Kros JM, French PJ, Sanson M, Idbaih A, Wesseling P, Enting R, Spliet W, Tijssen C, Dinjens WN, Gorlia T, van den Bent MJ. 0000392498 00000 n Missing chromosomes (parts of your genes) can cause cells to grow into a tumor. The p16INK4a/CDKN2A tumor suppressor and its relatives. Here are some possible symptoms that can occur. Oligodendrogliomas. CODEL: phase III study of RT, RT+ TMZ, or TMZ for newly diagnosed 1p/19q codeleted oligodendroglioma. (Mar 2001). 0000003918 00000 n "[Diagnostic and prognostic values of 1p and 19q deletions in adult gliomas: critical review of the literature and implications in daily clinical practice]" (in French). Oligodendroglioma - Overview - Mayo Clinic There are several different types of gliomas. Roughly 20 years ago, the first glioma-associated molecular signature was found with complete chromosome 1p and 19q codeletion being particularly common in histologically classic oligodendrogliomas. Oncol. Oligodendrogliomas are primary glial brain tumors that are divided into grade 2 and grade 3 tumors, with grade 3 tumors showing anaplastic features such as microvascular proliferation, necrosis, and increased mitotic rate; distinction between the two grades can be pathologically difficult. 2023 Feb 28;13(5):914. doi: 10.3390/diagnostics13050914. 2017 Nov 6. official website and that any information you provide is encrypted CDKN2A inhibits the interaction between the cyclin dependent-kinases CDK4 or CDK6 and D-type cyclins, preventing both the phosphorylation of the retinoblastoma (RB1) protein and the release of the elongation factor (EF2) (Weinberg, 1995; Sherr and Roberts, 1999). Daumas-Duport C, Scheithauer BW, Chodkiewicz JP, et al. The retinoblastoma protein and cell cycle control. National Comprehensive Cancer Network. 36:294-295. For example, a test may look at the changes in the tumor cells' genetic material, called DNA. Oligodendroglioma is most common in adults, but it can happen at any age. Brandes, A. While usually unexpressed in mature cells, cancer cells make use of this enzyme to promote their survival and increase proliferation. Oligodendroglioma, Brain Tumor: Causes, Symptoms & Treatments Molecular classification of anaplastic oligodendroglioma using next-generation sequencing: a report of the prospective randomized EORTC Brain Tumor Group 26951 phase III trial. Int. (2003). Finally, even though PTEN gene alterations have an unclear association with AO, their function in the control of cellular proliferation could explain their role in pathogenesis of AO. Bettegowda, C. (2000). doi: 10.1101/gad.13.12.1501. Mayo Clinic College of Medicine and Science, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic School of Graduate Medical Education, Mayo Clinic School of Continuous Professional Development, Mayo Clinic on Incontinence - Mayo Clinic Press, NEW Mayo Clinic on High Blood Pressure - Mayo Clinic Press, Mayo Clinic on Hearing and Balance - Mayo Clinic Press, FREE Mayo Clinic Diet Assessment - Mayo Clinic Press, Mayo Clinic Health Letter - FREE book - Mayo Clinic Press, Financial Assistance Documents Minnesota, Infographic: Molecular Classification of Gliomas, Intraoperative magnetic resonance imaging (iMRI), Research provides critical information about the size and growth speed of gliomas, Book: Mayo Clinic Family Health Book, 5th Edition, Newsletter: Mayo Clinic Health Letter Digital Edition. 0000245612 00000 n High-dose chemotherapy with stem cell rescue as initial therapy for anaplastic oligodendroglioma: long-term follow-up. Boston: Butterworth Heinemann; 1997. 0000225968 00000 n Lancet. The cause of most oligodendrogliomas is not known. Which of the following is a common genetic alteration in oligodendroglioma, Copyright PathologyOutlines.com, Inc. Click, 30150 Telegraph Road, Suite 119, Bingham Farms, Michigan 48025 (USA). 59(7):1345-52. 23 (3):457-467. PMC In a subgroup analysis, oligodendroglioma diagnosis was a favorable prognostic factor resulting in increased overall and progression-free survival; however, oligodendrogliomas were classified histologically in this study, not by 1p/19q status. van den Bent MJ, Taphoorn MJ, Brandes AA, et al. FOIA 0000008234 00000 n [QxMD MEDLINE Link]. (WC/jensflorian), Combined losses of 1p and 19q both and presence of IDH1 mutation in codon 132 or IDH2 mutation in codon 172 is required for final diagnosis and is prognostic and therapeutic relevant:[15][16][17]. Share cases and questions with Physicians on Medscape consult. Oligodendroglioma, IDH-mutant and 1p/19q-codeleted, WHO CNS Grade 2 (ICD-O: 9450/3). (2014). These tumors are called oligodendrogliomas because the cells resemble oligodendrocytes, a type of brain cell that supports and insulates nerve fibers in the CNS. 0000018524 00000 n Patients in arm A received RT with concomitant TMZ followed by adjuvant TMZ. 0000225852 00000 n 27, 332342. Curr. They occur primarily in adults (9.4% of all primary brain and central nervous system tumors) but are also found in children (4% of all primary brain tumors). The energy can come from X-rays, protons and other sources. doi: 10.1007/BF00177439, Mason, W. P., Krol, G. S., and DeAngelis, L. M. (1996). Cancer Res 2006; 66:9852. doi: 10.1200/JCO.2001.19.9.2449, Cloughesy, T. F., Filka, E., Kuhn, J., Nelson, G., Kabbinavar, F., Friedman, H., et al. The most common sign of an oligodendroglioma is a seizure. ROS and brain gliomas: an overview of potential and innovative therapeutic strategies. 0000276475 00000 n Abrey, L. E., Louis, D. N., Paleologos, N., Lassman, A. Mur, P.; Mollejo, M.; Ruano, Y.; de Lope, R. https://www.cancer.gov/types/brain/patient/adult-brain-treatment-pdq. Development. Interestingly, an in vitro treatment of cells with D-2HG also induced a similar methylation pattern (Lu et al., 2012) which further supports the vital role of this metabolite in epigenetic alteration and tumor formation. The tumor may enhance with contrast and is most often seen in anaplastic oligodendrogliomas. Transformation by the (R)-enantiomer of 2-hydroxyglutarate linked to EGLN activation. Retrospective studies have revealed that the post-operative seizure-free rate is 6780% (Luyken et al., 2003; Zaatreh et al., 2003; Benifla et al., 2006; Chang et al., 2008; Englot et al., 2011). Primitive Neuro-Ectodermal Tumors (PNET) Diagnosis and Treatment Where this happens in the body depends on which parts of the brain are affected by the tumor. Consequences of IDH1/2 mutations in gliomas and an assessment of inhibitors targeting mutated IDH proteins. The HR was 3.12 with a 95% CI of 1.267.19 (P = 0.014) (Jaeckle et al., 2021). Sipayya, V.; Sharma, I.; Sharma, KC. N Engl J Med. Roger E McLendon, MD is a member of the following medical societies: American Association of Neuropathologists, College of American Pathologists, Society for Neuro-OncologyDisclosure: Nothing to disclose. Wiestler, B.; Capper, D.; Hovestadt, V.; Sill, M.; Jones, DT. doi: 10.1074/jbc.M111.258947, Louis, D., Perry, A., Reifenberger, G., von, D. A., Figarella-Branger, D., Cavenee, W. K., et al. Neurosurgery 59, 12031214. 1987 Apr 1. 6, 2127. Aldape, K.; Burger, PC. doi:10.1043/1543-2165(2007)131[242:CAOQLA], Appin CL, Brat DJ. Phase II study of prolonged oral therapy with etoposide (VP16) for patients with recurrent malignant glioma. [QxMD MEDLINE Link]. J. Neurosurg. (2012). 0000230615 00000 n Oligodendrogliomas rarely spread outside of the CNS to other organs. Phase II study of first-line chemotherapy with temozolomide in recurrent oligodendroglial tumors: the European Organization for Research and Treatment of Cancer Brain Tumor Group Study 26971. This image reveals a calcified hypoattenuating lesion that is invading the corpus callosum. 0000015277 00000 n Retrospective studies have clearly defined the most common presenting symptoms and tumor locations. Phase III trial of chemotherapy plus radiotherapy compared with radiotherapy alone for pure and mixed anaplastic oligodendroglioma: Intergroup Radiation Therapy Oncology Group Trial 9402. Such tumors may demonstrate necrosis among its diagnostic features. 110, 60216026. This tumor exhibits oligodendroglial-type nuclei and scanty eosinophilic fibrillar cytoplasm amidst a mucinous background. doi: 10.3171/JNS/2008/109/11/0835, Sherr, C. J., and Roberts, J. M. (1999). (2012) showed that an IDH1 mutation can induce a methylation profile known as the G-CIMP signature, which is a glioma specific methylation pattern at CpG islands. Molecular analysis of chromosome 1 abnormalities in human gliomas reveals frequent loss of 1p in oligodendroglial tumors. Genes Dev. ; Burger, PC. Brain Pathol. Sahm F, Koelsche C, Meyer J, Pusch S, Lindenberg K, Mueller W, Herold-Mende C, von Deimling A, Hartmann C. Acta Neuropathol. They're the third most-common glioma, accounting for 2-5% of all primary brain tumours and 5-18% of gliomas. J. Neurooncol. Latini, A., Scussiato, K., Rosa, R. B., Llesuy, S., Bell-Klein, A., Dutra-Filho, C. S., et al. Shaw EG, Wang M, Coons SW, Brachman DG, Buckner JC, Stelzer KJ, et al. Ryskalin, L., Lazzeri, G., Flaibani, M., Biagioni, F., Gambardella, S., Frati, A., et al. 0000230464 00000 n Irinotecan therapy in adults with recurrent or progressive malignant glioma. 2010 Mar 1;16(5):1597-604. doi: 10.1158/1078-0432.CCR-09-2902. Oligodendrogliomas have a fried egg appearance under the microscope with sheets of round nuclei surrounded by clear cytoplasm. Accounting to up to 5% of all neuroepithelial tumors (Ostrom et al., 2017), oligodendroglial tumors have an incidence rate of around 1,000 new cases per year in the United States. ABM Salah Uddin, MD Private Practice, Norwood Neurology; Consulting Staff, Department of Neurology, St Vincent's Hospital Investigat. Oligodendroglial tumors are rare tumors that constitute part of the neuro epithelial tumors of the central nervous system. Ann. Oligodendroglioma. Oligodendrogliomas are commonly found in the white matter and the outer layer of the brain, called the cortex, but can form anywhere in the CNS. Youmans and Winn Neurological Surgery. The role of IDH2, on the other hand, is limited to the mitochondria where it catalyzes the same reaction as part of the tricarboxylic acid cycle (TCA). 0000127170 00000 n J. Pathol. (2016). J. Pathol. Clear cytoplasm - useful feature (if present). Alattar et al. Both authors have read and approved the final manuscript. No use, distribution or reproduction is permitted which does not comply with these terms. Polymorphous low-grade neuroepithelial tumor of the young: case report In addition to being a surrogate for oligodendroglial lineage, TERT mutations seem to have some prognostic significance (Dahlin et al., 2016). PLoS One 8:e68782. Curr Opin Neurol. The platelet-derived growth factor (PDGF) signaling system has been associated with the development and malignant progression of AO. J. Neurooncol. Upregulating mutations in the TERT promoter commonly occur in adult malignant gliomas and are strongly associated with total 1p19q loss. IDH1 and IDH2 mutations are prognostic but not predictive for outcome in anaplastic oligodendroglial tumors: a report of the European Organization for Research and Treatment of Cancer Brain Tumor Group. J Clin Oncol. (Feb 2007). 0000017251 00000 n Acad. Prospective studies are required to better . (2013). 6, 19. Recently, 1p/19q codeletion was independently validated as a favorable prognostic factor in low grade glioma.{ref35. Although these tumors were not examined for correspondence between PDGFR expression and PDGFR gene amplification, application of the same methodology on studies involving EGFR indicate that a high level of protein expression is to be expected in the future (Smith et al., 2000b). -. 29, 1139911408. As expected, patients with an IDH mutation and 1p19q co-deletion showed significant benefit in OS. doi: 10.1126/science.1239947, Kaloshi, G., Benouaich-Amiel, A., Diakite, F., Taillibert, S., Lejeune, J., Laigle-Donadey, F., et al. Cancer Interdiscipl. In the cytosol, the product of the reaction catalyzed by IDH1, alpha-KG, has been reported to be involved in multiple cellular pathways including hypoxia sensing, lipogenesis and epigenetic modification through its action on alpha-KG dependent dioxygenases such as TET and JmjC and other enzymes (Mason et al., 1996; Buckner et al., 2003; Abrey et al., 2006; Taliansky-Aronov et al., 2006). If you log out, you will be required to enter your username and password the next time you visit. 60, 11811189. (2016). (2016). (2006). doi: 10.1073/pnas.1303607110, Koelsche, C., Sahm, F., Capper, D., Reuss, D., Sturm, D., Jones, D. T., et al. 0000276357 00000 n Advances in the biology and treatment of oligodendrogliomas. 2005 Feb 1;11(3):1119-28. IDH1 mutation is sufficient to establish the glioma hypermethylator phenotype. Oligodendroglioma | Radiology Reference Article | Radiopaedia.org Oncol. doi: 10.1074/jbc.RA117.001385, Johnson, B. E., Mazor, T., Hong, C., Barnes, M., Aihara, K., McLean, C. Y., et al. (1996). CIMP + and MGMT-STP27 methylated tumors had a clear benefit from adjuvant PCV; the median OS in the RT and RT-PCV arms was 3.27 vs. 9.51 years (P < 0.0033), respectively for CIMP + tumors and 1.98 vs. 8.65 years (P < 0.0001) for MGMT-STP27 methylated tumors (van den Bent et al., 2013b). Int. Oncol. [QxMD MEDLINE Link]. ; Tihan, T.; Lin, D.; McDonald, W.; Nigro, J.; Feuerstein, B.; Jackson, S.; Cohen, K. et al. (2013) was the first to conduct a meta-analysis on PFS and OS in gliomas based on IDH mutations. Filipski, K.; Braun, Y.; Zinke, J.; Roller, B.; Baumgarten, P.; Wagner, M.; Senft, C.; Zeiner, PS. (1995). Major drugs utilized in the treatment of AO. doi: 10.1016/S0002-9440(10)61702-6, Shaw, E. G., Berkey, B., Coons, S. W., Bullard, D., Brachman, D., Buckner, J. C., et al. These alterations have correlated with a shorter event free survival (EFS; 29 vs. 53 months, p < 0.0001) and OS (48 vs. 83 months, p < 0.0001). [QxMD MEDLINE Link]. Burger PC, Rawlings CE, Cox EB, et al. doi: 10.1158/1078-0432.CCR-13-1157, van den Bent, M., Kros, J., Heimans, J., Pronk, L., Van Groeningen, C., Krouwer, H., et al. Fontaine D, Vandenbos F, Lebrun C, Paquis V, Frenay M (2008). (2001). The CODEL study is a phase 3 study whereby 36 patients with newly diagnosed grade III oligodendrogliomas were randomized to receive RT alone (Arm A), RT with concomitant and adjuvant TMZ (Arm B) or TMZ alone (Arm C) (Jaeckle et al., 2021). Interestingly, some tumors exhibited p16 hyperexpression without any chromosome 9p alterations and this was associated with a shorter EFS and OS. However, no results have proven enough benefit for treating patients with recurrent AO. ; Ohgaki, H.; Wiestler, OD. Medscape Education, Evolving Evidence on Human Papillomavirus Vaccination: Expert Updates on Head and Neck Cancer and the Role of Pharmacists, encoded search term (Oligodendroglioma) and Oligodendroglioma, Chemoprevention Strategies in Head and Neck Cancer, Head and Neck Cancer - Resection and Neck Dissection, Microarray Technologies in the Diagnosis and Treatment of Head and Neck Cancer, Cell Biology of Head and Neck Squamous Cell Carcinoma, Head and Neck Carcinoma in the Young Patient. 19, 6974. (2020). Gittleman H, Sloan AE, Barnholtz-Sloan JS. 0000255598 00000 n Oligodendroglioma Diagnosis and Treatment - NCI - National Cancer Institute Oligodendrogliomas account for approx 5% of all gliomas. Winn HR, ed. We Choose to Fight through Advocacy, Two-time Oligodendroglioma Survivor: Never Give Up Hope, NCI-CONNECT Rare Brain and Spine Tumor Network, U.S. Department of Health and Human Services. Central nervous system cancer. Typically, they have an indolent course, and patients may survive for many years after symptom onset. Cancer Sci. National Cancer Institute. Bannykh, SI. Anaplastic oligodendroglioma. 108, 227235. [4]. (2017). An estimated 11,757 people are living with this tumor in the United States. Clinical presentation of pediatric oligodendrogliomas - ScienceDirect ABM Salah Uddin, MD is a member of the following medical societies: American Academy of Neurology, American Epilepsy Society, American Medical AssociationDisclosure: Nothing to disclose. Oligodendrogliomas. Neuro Oncol. An independently validated survival nomogram for lower-grade glioma. (2012). The earliest reported results of the chemotherapy regimens, procarbazine, lomustine (CCNU), and vincristine (PCV), in AO were reported by Cairncross et al. Note: If molecular testing fails, cases should be classified as Oligodendroglioma, NOS. Therefore, PTEN is a target of 10q loss, and PTEN alterations are associated with aggressive tumor phenotypes regardless of chemosensitivity (Sasaki et al., 2001). Hence, cellular proliferation and dysregulation of pro-apoptotic pathways ensues (Ruas and Peters, 1998). Center for Cancer Research (2016). Neurosurg. Dysembryoplastic neuroepithelial tumor: a surgically curable tumor of young patients with intractable partial seizures. Primary Tumors of the Brain and Spinal Cord. "The 2016 World Health Organization Classification of Tumors of the Central Nervous System: a summary.". 2010, 111112. Oligodendroglial tumors are rare tumors, constituting approximately 5 percent of all neuroepithelial tumors of the central nervous system [ 2 ]. 17, 12481260. For unequivocal assessment of 1p/19q codeletion in oligodendroglial tumors, detection of whole-arm losses is key. 59, 495503. Am. 1994. Molecular subtypes of anaplastic oligodendroglioma: implications for patient management at diagnosis. Oncometabolite D-2-hydroxyglutarate inhibits ALKBH DNA repair enzymes and sensitizes IDH mutant cells to alkylating agents.