A Comparative Study of Histopathology of Astrocytomas with Intraoperative Cytology with Special Reference to MIB-1 Labelling Index

Abstract

Background: Although radiological imaging and surgical techniques have substantially improved, assessment of prognosis by grading astrocytoma has been challenging task for pathologists. We have tried to assess these tumours intraoperatively for rapid diagnosis. Also MIB-1Labelling index (MIB-1 LI) was done to study their proliferative activity. Aims: To compare and grade squash smear technique with histopathology to study its utility in diagnosis of astrocytomas. Further, to study correlation of various grades with their MIB-1 labelling index. Setting and Designs: This study was carried out in the Department of Pathology, SMS Medical College, Jaipur over a period of one year. Materials and Methods: Forty five cases of radiologically suspected astrocytomas were submitted for intraoperative cytology and later for histopathology. Two techniques were compared for ability to diagnose as well as grade the tumour. Also, MIB-1 LI were performed in biopsy tissue. Histopathological and immunological grades were compared. Results: Out of 45 cases 44(97.7%) correctly diagnosed by squash smear technique. Further significant differences seen in values of MIB-1 LI of high-grade and low-grade astrocytomas. A progressive increase in the MIB-1 LI was observed with increasing grades. In grade I astrocytoma MIB-1 LI was <0.05%. In grade II astrocytoma it varied from 0.8-2.6% except in one case where it was 3.2% who presented with a recurrent mass. In grade III, MIB-1 LI was 3.5% to 7.5%. In grade IV was 10-20%. Conclusion: Intraoperative cytology is fairly accurate and useful in intraoperative consultation. Also, MIB-1 LI can be a useful adjunct for grading particularly in small biopsies.

Keywords

• astrocytoma grading
• squash smear cytology
• proliferative index