A comparative study of conventional cytology and cell block in the diagnosis of pleural effusion with special reference to immunohistochemistry

Background: Body cavity fluids are evaluated by cell block (CB) technique. In conventional cytological smears (CS), appropriate identification of the cells as either reactive mesothelial cells or malignant cells is a diagnostic problem. In CB method, there is increase in cellularity, so it gives more morphological details of cells and improving the sensitivity of diagnosis. Sections obtained by CB method are also can be stored for future study like immunohistochemistry (IHC).

Aims and Objectives: The aim of the study was to determine the diagnostic efficacy of CB technique over conventional CS and to study of IHC in CB of malignant pleural effusion. 

Materials and Methods: This will be institution-based, cross-sectional, and observational study. The pleural fluid (except blood and pus) obtained by thoracocentesis from both male and female patient (>18 years of age) 100 cases was included in the study. Pleural fluid mixed with blood/pus, fluid from cystic lesion, and inadequate sample (<15 ml vol.) were excluded in the study. 

Results: Association between architectural pattern in CB versus architectural pattern in cytology smear showed statistically significant value Chi-square: 201.7417, P < 0.0001.

Conclusion: We may conclude that CB technique is better than conventional cytology smear technique especially in case of malignant pleural effusion. It increases true positive cases and decreases false negative cases. It also increases cellularity, maintain architectural pattern, and cellular morphology.