Comparison between crush/squash cytology and frozen section preparation in intraoperative diagnosis of central nervous system lesions

Aim: The aim of this study is to analyze the correlation/diagnostic accuracy of cytology and frozen section (FS) preparations in the intraoperative diagnoses of central nervous system (CNS) lesions. Materials and Methods: A total of 63 cases of CNS lesions were included in the study from July 2012 to January 2015 at a tertiary care referral hospital. Intraoperative specimens were used for crush/squash smears and FS and correlated with the final histopathological diagnosis. Results: Majority of the patients (73.02%) were presenting in the age range of 21–50 years. There was a slight female preponderance with male-to-female ratio of 1:1.1. Two out of 63 cases were excluded from the cytology correlation analysis due to inadequate materials and 3 out of 63 cases were excluded from the FS correlation analysis due to freezing artifacts. The diagnostic accuracy of cytological preparation was 80.33% for complete correlation with histopathology and was increased to 93.44% for adding the partial correlations. The corresponding figures for FS were 81.67% and 93.33%, respectively, and the difference was insignificant (P = 0.971). The sensitivity, specificity, positive predictive value, and negative predictive value in detecting neoplastic condition on cytology were 94.4%, 85.7%, 98.07%, and 66.67%, respectively, and that of FS were 96.15%, 75%, 96.15%, and 75%, respectively. The corresponding P = 0.872, 0.652, 0.986, and 0.561, respectively. Conclusion: Crush and FS preparation are considered as effective diagnostic procedures for rapid intraoperative diagnosis in CNS lesions without any significant difference in results and when applied simultaneously can produce a higher diagnostic accuracy complementing each other's results.