Gangliogliomas are rare tumors of the Central Nervous System. Five Gangliogliomas were diagnosed out of 1560 brain tumours surgically resected out in a period of 5years accounting for 0. 32%. We have tried to discuss in detail the pathological features of these tumours and have mentioned the clinical and radiological features associated with them. All the slides, tissue blocks and pathology reports of the surgical specimens of gangliglioma were reviewed and the clinical and radiological data reviewed. The ages of the patients ranged from 7 -65 years with 4 males and 1 female. The tumors were located in the lateral ventricle (a rare site), temporal, parietal and the frontal lobes with duration of seizures varying from 1-9 years. The tumors were diagnosed by the presence of a dual population of neoplastic ganglionic and glial components. The glial components consisted of pilocytic astrocytes (l case), fibrillary astrocytes (2 cases), oligodendrocytes (1 case) and anaplastic astrocytes and oligodendrocytes (1 case). There was one-grade I GG, three-Grade II GGs and one-grade III GG. Astrocytes were the commonest glial component of GGs, either pilocytic or fibrillary. Oligodendrocytes as the glial component of GGs was seen in 2 cases one of which was anaplastic and this is a rare finding.

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 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 METHODSA 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. RESULTSAmong 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. CONCLUSIONIn 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.