Cytomorphological comparison of alcohol–formalin cell-block technique with conventional cytology in serous effusions in a low-resource setting

Abstract

Our study compared the diagnostic accuracy of the 10% alcohol–formalin cell-block (CB) technique against traditional smears (CS) in serous effusions over 1 year. CB outperformed CS by detecting 7 missed cases and diagnosing 177 benign, 5 suspicious and 26 malignant cases compared to CS's 180 benign, 9 suspicious and 19 malignant cases. Using histopathology as a gold standard, CB showed a sensitivity of 96.4%, specificity of 98.3% and diagnostic accuracy of 98.1%, significantly higher than CS's 79.3% sensitivity, specificity of 97.7% and 95.2% accuracy. Using a 10% alcohol–formalin method, CB also excelled in cytomorphological characterization, especially in background elements, cellularity and cellular architecture. CB offered improved diagnostic accuracy and allowed extra sections for additional tests. In resource-constrained settings, combining CS and CB enhances cytological assessment.