Visual Assessment and Rapid On-Site Evaluation for Touch Imprints From Biopsy Tissue in Diagnosing Pleural Effusion Using Medical Thoracoscopy

Pleural effusion is a common clinical problem, and distinguishing malignant from benign causes is crucial for guiding treatment. Medical thoracoscopy allows direct visualization of the pleural surfaces and enables targeted biopsies. Although experienced clinicians often rely on the gross appearance of pleural abnormalities, visual assessment alone can be limited by overlap between malignant and benign features. Rapid On-Site Evaluation (ROSE) of touch-imprint cytology has emerged as a technique that may provide immediate microscopic information during the procedure, potentially improving diagnostic accuracy and reducing the need for repeat procedures.

This observational study prospectively evaluated the diagnostic performance of thoracoscopic visual inspection compared with ROSE during medical thoracoscopy. Thirty-three adult patients undergoing thoracoscopy for undiagnosed pleural effusion or suspected pleural disease were included. During the procedure, the thoracoscopist recorded a visual impression of whether pleural findings appeared malignant or benign. Touch-imprint slides were prepared from pleural biopsy specimens and assessed immediately by a trained cytopathologist using ROSE. All biopsy samples were subsequently analyzed by formal histopathology, which served as the reference standard.

The study measured sensitivity, specificity, accuracy, predictive values, receiver operating characteristic (ROC) curves, and agreement using Cohen's kappa. Visual assessment showed high sensitivity but limited specificity. ROSE demonstrated high overall accuracy and strong agreement with final histopathology, suggesting it may substantially improve real-time diagnostic confidence. By integrating both visual inspection and ROSE, clinicians may achieve more reliable intraoperative decision-making and potentially streamline patient management during thoracoscopy.