# Comparative Diagnostic Yield of Cytology, Imprint Cytology, and Histopathology in Medical Thoracoscopic Pleural Biopsies: A Prospective Observational Study

## TL;DR

This study compares the diagnostic accuracy of imprint cytology, brush cytology, and histopathology in pleural biopsies, finding that imprint cytology performs best.

## Contribution

The study provides a direct comparison of diagnostic techniques in thoracoscopic pleural biopsies using a range of statistical metrics.

## Key findings

- Imprint cytology had higher sensitivity and NPV than brush cytology.
- A positive imprint cytology result significantly predicts biopsy positivity.
- Imprint cytology's diagnostic performance is close to histopathology.

## Abstract

Background

Pleural effusion is a common clinical problem with varied etiologies. Timely diagnosis is essential for appropriate treatment. This study aimed to compare the diagnostic performance of brush cytology and imprint cytology, with histopathology, in pleural biopsy specimens obtained via thoracoscopy.

Methods

This prospective observational study included 96 patients with undiagnosed exudative pleural effusion undergoing medical thoracoscopy. Biopsy samples were analyzed by histopathology, brush cytology, and imprint cytology. Diagnostic metrics, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), McNemar’s test, receiver operating characteristic (ROC) analysis, and logistic regression, were computed.

Results

Imprint cytology demonstrated higher sensitivity (73.17%) and NPV (76.60%) compared to brush cytology (65.85% and 72.00%, respectively). Logistic regression showed that a positive imprint result predicted biopsy positivity with an odds ratio of 5.17. ROC analysis confirmed superior diagnostic performance for imprint cytology.

Conclusion

Imprint cytology is a reliable, rapid, and effective diagnostic tool in thoracoscopic pleural biopsy evaluation, with performance metrics approaching those of histopathology.