Histological spectrum of ependymomas and correlation of p53 and Ki-67 expression with ependymoma grade and subtype.

BACKGROUND: Clinical and histological criteria for ependymoma prognosis are well recognized. Recently few studies have been done based on Immunohistochemistry for prognostication of these tumours. In this study we have correlated the histological spectrum with immmunoexpression of p53 and Ki67 in these tumors. AIMS: To know the incidence of ependymomas; study their morphological spectrum and to evaluate expression of P53 and Ki 67 in different morphological subtypes. MATERIAL AND METHOD: A retrospective study was preformed on 70 ependymomas received in a period between 1994 and 2001. Entire tissue received was processed for routine paraffin embedded H&E stained sections. Immunocytochemistry was performed using antibodies to GFAP, EMA, Pancytokeratin and synaptophysin, to differentiate papillary ependymoma from choroid plexus papilloma; clear cell ependymoma from oligodendroglioma and central neurocytoma; ependymoblastoma from other embryonal tumours. p53 and Ki-67 immunohistochemistry was performed to correlate their expression with various tumour grades and subtypes. RESULTS: There were 3 cases (4.2%) of Grade I ependymoma (2 cases of myxopapillary ependymoma and 1 case of subependymoma); 57 cases (81.5%) of ependymoma grade II (43 of these were of classical variety, 11 of clear cell ependymoma, 2 of papillary and 1 case of cellular ependymoma). There were 9 cases (12.8%) of anaplastic ependymoma (one of these was a clear cell ependymoma and 1 case (1.5%) of ependymoblastoma CONCLUSION: p53 and Ki67 indices can be used in routine diagnostic laboratories to supplement the tumor grade on histology and more studies with follow up should be performed to analyse the prognosis of different subtypes. The expression of Ki 67 and p53 was significantly higher in anaplastic ependymomas. 4 out of 11 cases of clear cell ependymomas showed higher Ki 67 indices as compared to classical grade II ependymomas, thus further highlighting the importance of differentiating the various subtypes.

Histological analysis of cystic tumour like lesions of central nervous system.

True cysts of the central nervous system (CNS) are rare lesions. A retrospective study of patients with symptomatic non-neoplastic cystic lesions of CNS operated in the Department of Neurosurgery, G.B. Pant Hospital, New Delhi between Jan 1994 and Feb 2001 was conducted. Parasitic cysts, cystic transformation of hemmorhages, vascular malformations and cystic tumours were excluded from the study. A total of 109 cases were reviewed. There were 34, 27, 17, 16, 8, 3 and 2 cases of epidermoid, arachnoid, dermoid, colloid, neurenteric, Rathke's and ependymal cysts and 1 case each of choroid plexus and glial cysts. The clinical presentations, locations, incidence and pathogenesis of these cysts is discussed.