Comparative Efficacy of Imprint and Squash Cytology in Diagnosing Lesions of the Central Nervous System

Introduction: Central nervous system lesions can be localized precisely with the help of computerizedtomography (CT). However, rapid cytological diagnosis of lesions by imprint and/or squash smear technique isuseful to assist the operating surgeon to avoid unnecessary craniotomy. The present study was conducted withthe aim to study the sensitivity, specificity and diagnostic accuracy of the two types of smears in central nervoussystem lesions while taking histology as gold standard. Materials and
Methods: In the present study 149 lesionsof the central nervous system were studied by squash and imprint smear techniques and results were comparedwith histology. Cytology smears were stained with May-Grunwald-Giemsa and Pap stain. Histopathology smearswere stained with haematoxylin and eosin stain.
Results: Out of 149 cases, 85 were malignant and 64 cases wereeither benign or non-neoplastic lesions. The sensitivity, specificity and diagnostic accuracy by squash smearwere 90.6%, 87.5% and 89.3% respectively and that of the imprint smears were found to be 92.9%, 90.6%and 92.0%. The combined sensitivity, specificity and diagnostic accuracy of both techniques were even greater(95.3%, 93.8% and 94.6%).
Conclusions: The present study showed that imprint smear examination is superiorto the squash smear for diagnosing lesions of the central nervous system.