The application of probe-based confocal laser endomicroscopy in pleural diseases

Probe-based confocal laser endomicroscopy (pCLE) constitutes a cutting-edge in vivo imaging technology, yet its application within the realm of respiratory medicine, especially of pleural disease, is still in its incipient phase. This single-center, retrospective analysis encompassed patients admitted to our department between August 2023 and January 2024 for the investigation of "pleural effusion of unknown etiology," who subsequently underwent medical thoracoscopy augmented by pCLE examination. The study culminated in a comprehensive analysis of the pCLE imaging attributes of pleural lesions, integrating cytological and histopathological findings to delineate the characteristics of benign vs malignant pleural diseases. A total of 18 patients were included in the study (5 cases of lung adenocarcinoma, 10 cases of tuberculous pleuritis, and 3 cases of parapneumonic effusion), with 44 valid pCLE video recordings collected for final data analysis. The analysis of qualitative criteria for pCLE imaging revealed that the size, morphology, and fluorescence consistency of cells were effective in distinguishing between benign and malignant pleural diseases (P < .001). The quantitative criteria analysis indicated that the mean cell size in malignant pleural diseases was significantly larger than that in benign conditions, while the cell density was lower in malignant cases compared to benign ones. No significant difference was observed in the maximum vessel diameter between the 2. Additionally, differentiating pCLE images between tuberculous pleural effusion and parapneumonic effusion proved to be challenging. The findings indicate that pCLE is viable modality for the examination of the pleural space, with distinct imaging characteristics observed in benign vs malignant pleural diseases.