HISTOPATHOLOGICAL PATTERN AND EXPRESSION OF Ki-67, EGFR IN CENTRAL NERVOUS SYSTEM TUMOURS
Journal of Evolution of Medical and Dental Sciences
BACKGROUND Central Nervous system (CNS) tumours constitute only about 1-2% of all neoplasms, but they show a varied histopathological spectrum. A WHO grading scheme is followed in the reporting of these tumours which play a key role in deciding the choice of therapies. Immunohistochemical markers like Ki-67 and EGFR are found to have a significant role in predicting the behaviour of these tumours. Hence in tumours where proper grading becomes difficult, the usage of these markers will be
... kers will be extremely helpful. In this study, the histopathological pattern, grading and expression of Ki-67 and EGFR in CNS tumours, received during the stu dy period of 18 months, are described. Thereafter the relationship between the expression of these markers and the WHO grades is also evaluated. MATERIALS AND METHODS A descriptive study was conducted to describe the histopathological pattern and the expression of Ki-67 and EGFR in CNS tumours received in the Department of Pathology, Government Medical College, Kottayam for a period of 18 months (June 2017 -November 2018). The relationship between the expression of these markers and the histological grades was also evaluated. Statistical analysis was done with available software. RESULTS Among the 80 cases of CNS tumours studied, 48 cases (60%) were Meningiomas. Most of the cases had a Ki 67 value between 0-5 % (50 cases, 62.5%). It was found that in all types of CNS tumours studied, Ki-67 increased with increase in WHO grade. Among the glioma cases studied, 70.8% of them had an EGFR score of 3+ and among meningiomas, 62.5% had an EGFR Immunoreactive score (IRS) between 11 and 15. By statistical analysis, it was found that both WHO grade and EGFR expression in these tumours are associated. But in case of gliomas, increase in WHO grade improves our prediction for EGFR to be high (3+) and among meningiomas, increase in WHO grade improves our prediction for EGFR to be low (0-5). In case of remaining CNS tumours, majority of them showed EGFR negativity. CONCLUSION In our study, Meningiomas were the most common histological type. Ki-67 values in all types of CNS tumours increased with increase in WHO grades. All gliomas and meningiomas showed expression of EGFR. A significant association exists between WHO grades and EGFR expression of these tumours.