Background: Squash smears play a major role in intraoperative cytological diagnosis of central nervous system (CNS) lesions operated by open craniotomy, as it not only reveals the nature of the lesion and also helps to monitor and modify the approach of surgery. Inherent soft nature of the CNS lesions yields good quality material on squash smears.
Aim of the study
1. To evaluate the role of imaging techniques, squash smears and histopathology in diagnosing various lesions of central nervous system.
2. To evaluate the overall accuracy, sensitivity and specificity of imaging techniques and squash smears in diagnosing high grade and low grade tumours in central nervous system
Material and Methods: This is prospective study for a period of two years from 2008 to 2010 at the department of Pathology Andhra Medical College, Visakhapatnam .In all the 81 cases the squash smear results were correlated with the preoperative radiological findings and final histopathology report.
Results: Out of 81 cases, 78 (96.29%) cases were correlated with the final histopathological diagnosis. Diagnostic accuracy of squash smears in differentiating high grade tumours in CNS from low grade tumours was 97.1% and that of radiology in our study was 83.82%. Sensitivity of squash smears was 90.9% and specificity was 100%. Sensitivity of imaging methods was 57.14% and specificity was 95.74%.Overall correlation with histopathological diagnosis on squash smears was 96.29% (n=78) and radiology was 83.9% (n=68). High percentage of correlation in our study was due to prior recording of clinical and radiological findings along with neurosurgeon's intraoperative opinion.
Conclusion: Squash smears play a major role in diagnosing central nervous system lesions intraoperatively.
Intraoperative diagnosis by squash smears can be done with high accuracy when correlated with clinical, radiological and surgeon's intraoperative findings.
