Cell Block versus Cytospin in the Detection of Malignancy in Body Fluids: A Cross-sectional Study

Abstract

Introduction: Cytological examination of body fluids is a commonly performed investigation that provides information about inflammatory and malignant lesions, aiding in the diagnosis of effusion aetiology and potential differential diagnoses. The cell block technique, combined with cytospin study, offers an additional advantage in such cases. Aim: To compare the diagnostic utility of cell block method and cytospin method in detecting malignancy in body fluids. Materials and Methods: This cross-sectional observational study was conducted for a period of two years at Bharati Vidyapeeth (DTU) Medical College Hospital and Research Centre in Pune, Maharashtra, India. A total of 100 body fluid samples were analysed, including 73 pleural fluids, 24 ascitic fluids, and 3 pericardial fluids. Each fluid sample was divided into two equal parts: one processed for cytospin (CYTOTEK), and the other processed to create a cell block. Four Immunohistochemistry (IHC) markers (Thyroid Transcription Factor-1 (TTF-1), Cytokeratin 7 (CK7), Cytokeratin 20 (CK20), and Calretinin) were applied as needed. Data analysis was performed using the Statistical Package for Social Sciences (SPSS) version 25.0, and results were calculated using the Chi-square test. Results: Of the total 100 fluid samples, 65 were negative, 17 were positive, and 18 were suspicious for malignancy using the cytospin method. In comparison, the cell block method identified 63 samples as negative, 29 as positive, and 8 as suspicious for malignancy. The cell block method exhibited a higher sensitivity (100.00%) and specificity (94.03%) than the cytospin method (81.82% and 88.06%, respectively) in this study. Conclusion: Cell block method accurately diagnosed 10 cases as positive for malignancy that were initially deemed suspicious on cytospin smear. Therefore, the cell block method proved to be a superior diagnostic tool for malignancy compared to cytospin smear. Given that cell blocks allow for longer storage and additional analysis such as IHC and microarray, they should be adopted in addition to cytospin for effusion cytology

Keywords

• effusion
• immunohistochemistry
• malignant