Authors: Mahvish Hussain , Laeeq ur Rahman , Shazia Riaz , Samina Zaman , Alia Ahmad , Amber Goraya , Rabia Aqeel , Abeera Assad Rasool , Masood Sadiq

Abstract

Background and Objective:
Evaluation of intraoperative frozen section (FS) in central nervous system (CNS) lesions  is an invaluable tool to ensure adequacy of tissue obtained to establish the diagnosis and is consistently practiced for rapid assessment and ancillary studies. The objective of this study was to determine the diagnostic concordance between frozen section for the pediatric CNS lesions considering Histopathology as a gold standard in the local pediatric population with respect to age and gender.
Methods:
This cross-sectional study was conducted at the Department of Histopathology, University of Child Health Sciences & The Children’s Hospital, Lahore, Pakistan. The biopsy specimens from 35 pediatric patients with CNS tumors were sent fresh frozen and in formalin, both, for analysis of the diagnostic accuracy of FS while taking formalin fixed paraffin embedded (FFPE) tissues as gold standard. 
The data was analyzed by using statistical tests of significance.
Results:
Comparing FS with FFPE tissues,  77.1 % cases showed complete concordance,  17% were partially concordant while only 5.7% cases were discordant.  Male patients demonstrated higher (10.5%) discordance as compared to females (0%) (p= 0.251). Across age groups, concordance rates vary with no statistically significant differences.
Conclusion:
 The diagnostic concordance of frozen sections  is quite higher in CNS lesions in comparison to formalin fixed paraffin embedded tissues with certain limitations occurring in different tumors. Histopathological review and clinical correlation is mandatory for reaching a conclusive diagnosis in challenging cases. 

Keywords: frozen section, histopathological diagnosis, concordance