Amina Salim Mohammed (1), Hatem Abdulmajeed Al-Nuaimi (2)
Background: Brain tumors constitute 1–2% of adult tumors, with glioblastoma (GBM) and meningioma being the most frequent subtypes. Mutations in the isocitrate dehydrogenase (IDH) gene are associated with gliomas and have prognostic significance. Specific Background: Although IDH mutation is well-documented in secondary glioblastoma and diffuse gliomas, data remain scarce in Iraqi populations. Knowledge Gap: Limited studies exist on the prevalence and diagnostic role of IDH mutations in primary brain tumors in Mosul, Iraq. Aim: This study investigates the frequency, histopathological characteristics, and immunohistochemical expression of IDH mutations in primary brain tumors. Results: Among 41 cases (mean age 36.6 years), GBM (26.8%) and meningioma (22%) were predominant. Supratentorial tumors accounted for 75.6%. IDH immunohistochemistry in 10 cases revealed four positive results: medulloblastoma (25%), GBM (50%), atypical meningioma (100%), and gliosarcoma (100%). Meningioma grade I and anaplastic astrocytoma showed negative IDH expression. Novelty: This is the first documented case series in Mosul to highlight IDH expression patterns across multiple tumor subtypes, including rare positivity in atypical meningioma and gliosarcoma. Implications: Findings underscore IDH testing as a valuable diagnostic tool, supporting future integration into local neuropathological practice.
Highlights:
IDH mutation detected in multiple tumor subtypes.
GBM was the most frequent brain tumor.
Diagnostic role of IDH confirmed in local population.
Keywords: Glioblastoma, IDH Mutation, Gliosarcoma, Isocitrate Dehydrogenase, Brain Tumors
[1] J. Ferlay, I. Soerjomataram, R. Dikshit, S. Eser, C. Mathers, M. Rebelo, et al., “Cancer Incidence and Mortality Worldwide: Sources, Methods and Major Patterns in GLOBOCAN 2012,” Int. J. Cancer, vol. 136, no. 5, pp. E359–E386, 2014.
[2] I. Khan, M. Bangash, S. Baeesa, A. Jamal, A. Carracedo, F. Alghamdi, et al., “Epidemiological Trends of Histopathologically WHO Classified CNS Tumours in Developing Countries: Systematic Review,” Asian Pac. J. Cancer Prev., vol. 16, no. 1, pp. 205–216, 2015.
[3] N. Manoharan, P. K. Julka, and G. K. Rath, “Descriptive Epidemiology of Primary Brain and CNS Tumours in Delhi, 2003–2007,” Asian Pac. J. Cancer Prev., vol. 13, pp. 637–640, 2012.
[4] P. L. Lantos, D. N. Louis, M. F. Rosenblum, and P. Kleihues, “Tumours of the Nervous System,” in Greenfield’s Neuropathology, 7th ed., D. I. Graham and P. L. Lantos, Eds. London, U.K.: Arnold, 2002, pp. 707–872.
[5] H. Scherer, “Cerebral Astrocytoma and Their Derivatives,” Am. J. Cancer, vol. 40, pp. 159–198, 1940.
[6] P. Kleihues and H. Ohgaki, “Primary and Secondary Glioblastomas: From Concept to Clinical Diagnosis,” Neuro Oncol., vol. 1, no. 1, pp. 44–51, 1999.
[7] H. Ohgaki and P. Kleihues, “Genetic Pathways to Primary and Secondary Glioblastoma,” Am. J. Pathol., vol. 170, no. 5, pp. 1445–1453, 2007.
[8] H. Ohgaki, P. Dessen, B. Jourde, S. Horstmann, T. Nishikawa, P. L. Di Patre, et al., “Genetic Pathways to Glioblastoma: A Population-Based Study,” Cancer Res., vol. 64, no. 19, pp. 6892–6899, 2004.
[9] D. N. Louis, H. Ohgaki, O. D. Wiestler, W. K. Cavenee, P. C. Burger, A. Jouvet, et al., “The 2007 WHO Classification of Tumours of the Central Nervous System,” Acta Neuropathol., vol. 114, no. 2, pp. 97–109, 2007.
[10] S. Khan, M. E. Kambris, and E. T. AlShamsi, “Epidemiology of Brain Tumors in the United Arab Emirates: A National Registry Cross-Sectional Study,” BMC Neurol., vol. 20, no. 301, pp. 1–8, Aug. 2020.
[11] R. S. Arora, R. D. Alston, T. O. Eden, E. J. Estlin, A. Moran, and J. M. Birch, “Age–Incidence Patterns of Primary CNS Tumors in Children, Adolescents, and Adults in England,” Neuro Oncol., vol. 11, no. 4, pp. 403–413, 2009.
[12] G.-M. Wang, K. Nabors, M. R. Barnholtz-Sloan, Y. E. Jenkins, J. Gittleman, J. Ostrom, et al., “Importance of the Intersection of Age and Sex to Understand Variation in Incidence and Survival for Primary Malignant Gliomas,” Neuro Oncol., vol. 24, no. 2, pp. 302–310, 2022.
[13] B. Holleczek, D. Zampella, S. Urbschat, F. Sahm, A. von Deimling, J. Oertel, et al., “Incidence, Mortality and Outcome of Meningiomas: A Population-Based Study from Germany,” Clin. Neurol. Neurosurg., vol. 186, p. 101562, Oct. 2019.
[14] H. A. Wanis, H. Møller, K. Ashkan, and E. A. Davies, “The Incidence of Major Subtypes of Primary Brain Tumors in Adults in England 1995–2017,” Neuro Oncol., vol. 23, no. 8, pp. 1371–1382, Aug. 2021.
[15] O. D. Sabunga, M. R. Arsyad, A. R. Rivai, and M. H. Nasrum, “Analysis of Isocitrate Dehydrogenase (IDH) Expression in Astrocytoma Patients: Cases of South Sulawesi, Indonesia,” Bali Med. J., vol. 11, no. 1, pp. 184–188, 2022.
[16] N. S. Omer, J. A. Jalal, and A. T. Ismael, “IDH1 (R132H) Immunoexpression in Glioma,” J. Kurdistan Board Med. Specialties, vol. 4, no. 1, pp. 57–63, 2018.
[17] Z. M. Shaban, S. R. Al-Aubaidy, and A. D. Hameedi, “IDH1 Mutation in Gliomas in Baghdad by Immunohistochemical Study,” Int. J. Genet. Genomics, vol. 6, no. 1, pp. 1–7, 2018.