Diagnostic utility of intraoperative squash smear cytology of Intra-cranial lesions in a resource limited setup of central India.

Introduction: Intraoperative squash smear cytology is a useful diagnostic tool in case of CNS lesions. In resource poor countries where frozen section is unavailable, cytology is the mainstay method in giving a rapid intraoperative diagnosis which helps Surgeons regarding the extent of excision. The current study aims to assess the feasibility and accuracy of intraoperative squash cytology in evaluation of CNS tumors. Definitive diagnosis is confirmed by histopathological examination. Materials and methods: This retrospective observational study was carried out at Department of Neuropathology. All patients diagnosed with space occupying lesion (SOL) in CNS were enrolled in the study. Intra-operative cytological diagnosis was compared to histopathological diagnosis. WHO classification of CNS tumors 2021 was used to classify tumors. Results: Total seventy patients with intracranial SOLs were enrolled in this study who were operated for the same and their specimens were examined. Two samples were found to be inadequate and not included in final analysis. Mean age was 38.8 ± 17.85 (SD). Male-female ratio was 1.5:1 with 41 (60.3%) males and 27 (39.7%) females. 58 had neoplastic and rest 10 had non-neoplastic lesions. Complete concordance was achieved in 61 cases (Diagnostic Accuracy-88.2%). 3 (4.4%) cases showed partial concordance and 4 (5.9%) were discordant. For detection of malignant lesions through squash smear cytology overall Sensitivity was 73.9%, Specificity-97.8%, Positive Predictive Value-94.4% and Negative Predictive Value-88%. Conclusions: Squash smear cytology is a simple, rapid and cost-effective method relying solely on the expertise of pathologist. High diagnostic accuracy can be achieved with squash cytology by taking clinical and radiological findings into consideration.