Introduction: WT1 is a transcription factor related to growth and differentiation of cells. WT1 overexpression is observed in majority of primary glial tumours. However, it is differential expression of WT1 in different grades of tumour, that might influence the biological behavior of gliomas and thus prognosis. At present, as WT1 is regarded as a molecular target for immunotherapy for malignant gliomas, an appropriate evaluation of WT1 expression is essential. The present study was planned to assess the WT1 expression in various grades and types of glial neoplasm and correlate this with mean mitosis and tumour grade so as to exclude or include WT1 as a potential prognostic factor in patients with glial tumours.

Materials and Methods: A descriptive observational study was carried out in Department of Pathology, S.M.S. Medical College, Jaipur (Rajasthan). Total 50 cases of glioma were included in the study.These were stained with Hematoxylin and Eosin followed by Immunostaining with WT1. Clinical, histopathological and Immunohistochemical profile of glial tumours were recorded and analysed.

Results: Mean age of study subjects was 35.64±16.03 years (male 38.65±15.06 years and female 30.74±16.74 years). 62% were males and 38% were females. Glioblastoma was the most frequent neoplasm (40%). Highest number of Tumours belonged to Grade-IV (40%) followed by Grade-II (38%), Grade-I (12%) and Grade-III (10%) according to WHO grading system for glial tumours. Highest mean mitotic value was obtained in grade-IV tumours (7.80) while it was 0 in grade-I tumours (p<0.001). Positive staining for WT 1 immunoexpression was observed in 45 cases (90%) ranging from score 2 to score 6. Mean WT1 score for grade-I tumours was 2.50, for grade-II tumours 2.95, for grade-III tumours 2.60 and for grade-IV tumours 5.60 (p<0.001). There was a strong correlation between WHO grade, mitosis and WT1 Score. Also, WT1 showed a direct independent correlation with mitotic activity of tumours.

Conclusion: WT1 immuno-expression bears a direct relation to tumour grade as well as mitotic activity. Thus, it appears to be involved in tumour growth and bears a prognostic significance. This makes it a useful molecular target for immunotherapy.

Keywords: Glial Neoplasm, Histopathology, Immunohistochemical, WT1 immunoexpression.

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Vijay Ramita

Postgraduate Student, Department of Pathology, SMS Medical College, Jaipur, Rajasthan, India