Use of Intraoperative Squash Smear in Diagnosis of Central Nervous System Tumors with its Histopathological Correlation

Abstract

Introduction: Squash smear preparation is a simple and rapid methodology for fairly accurate
intraoperative diagnosis of CNS space occupying lesions. It has emerged as an important indispensible
intraoperative diagnostic aid guiding the neurosurgeon and helping in better management of patients.
The current study was undertaken to study CNS tumors by squash cytology and correlating them with
histological diagnosis.
Aims: To evaluate the accuracy and utility of intraoperative squash smear cytology in the evaluation
of CNS tumors.
Materials and Methods: A retrospective study was conducted in the Department of Pathology in a
tertiary care hospital from November 2019 to November 2020. A total of 74 consecutive cases were
included. Squash smears were prepared from the intraoperative samples and biopsy samples were
processed regularly. Hematoxylin and eosin staining was done and squash smear cytology results were
correlated with the final histopathological diagnosis.
Results: Out of the 74 cases studied, histopathological diagnosis was compatible with the cytological
diagnosis in 56 cases, pertaining to 75.67% accuracy. Remaining 18 cases showed partial discrepancy
as in tumor grading or complete discrepancy.
Conclusion: This study shows a high degree of cytohistological correlation. With clinicoradiological
correlation, squash smear cytology could be the preferred method for intraoperative diagnosis of CNS
tumors.