Pathological Evaluation of Diffuse Gliomas Using IDH1 and ATRX in a Resource-Limited Setting

Introduction: Classification of gliomas based on tumor histology remains the gold standard in the diagnosis and prognosis of gliomas. However, the recent World Health Organization (WHO) classification has included molecular studies for diagnosis and prognostication. Immunohistochemical markers such as isocitrate dehydrogenase 1 (IDH1) and alpha thalassemia/mental retardation syndrome X-linked (ATRX) can be used for the diagnosis and prognosis of the majority of gliomas. Objectives: We aim to study the frequencies of IDH1 and ATRX mutations in diffuse gliomas using surrogate immunohistochemical markers and correlate histopathological findings of gliomas with immunohistochemical findings. Material and methods: This was a retrospective study of one-year duration from January 2022 to December 2022, conducted in the department of pathology. Relevant data was retrieved from medical records. Histopathology blocks were collected and sent for immunohistochemical studies using tissue microarray for IDH1 and ATRX. Statistical analysis: Qualitative data were expressed in percentages and proportions. The difference in proportion was calculated using the chi-square test, and a p-value of <0.005 was taken as significant. Results: A total of 51 cases of diffuse gliomas were included in the study. The frequency of IDH1-positive diffuse astrocytomas was 33 (64.7%), and loss of ATRX was seen in 12 (23.5%) cases. Conclusion: Immunohistochemistry serves as a surrogate marker to detect molecular alterations in diffuse gliomas.