Comparative Diagnostic Utility of Cell Cytology, Cell Block, Pleural Brushing, and Pleural Biopsy in Exudative...

Exudative pleural effusion is a common clinical problem with diverse etiologies, often requiring invasive procedures for definitive diagnosis. While conventional cytology is widely used, its diagnostic yield remains limited. Ancillary methods such as cell block (CB) preparation, pleural brushing, and thoracoscopic pleural biopsy may enhance diagnostic accuracy.

This study aimed to evaluate and compare the diagnostic utility of pleural fluid cell cytology (CC), CB, pleural brushing, and pleural biopsy in patients with exudative pleural effusion.

This prospective observational study was conducted at a tertiary care hospital and included 49 patients with exudative pleural effusion. All patients underwent pleural fluid analysis, cytology, CB preparation, and medical thoracoscopy with pleural brushing and biopsy. Diagnostic yields, sensitivity, specificity, positive predictive value, and negative predictive value of each modality were calculated using pleural biopsy as the reference standard.

The study population had a mean age of 52.4 ± 15.2 years, with 59% of male participants. Malignancy was the most frequent etiology (55%), followed by tuberculosis (28.5%) and nonspecific pleuritis (14.2%). Diagnostic yield was highest for pleural biopsy (83.6%), followed by pleural brushing (80.9%), CB (61.9%), and CC (38.1%). Sensitivity and specificity were 44.4% and 100% for cytology, 59.2% and 100% for CB, and 80.9% and 100% for pleural brushing, respectively. The combination of cytology and CB improved diagnostic yield compared to cytology alone.

Conventional cytology alone has limited sensitivity in diagnosing exudative pleural effusions. CB and pleural brushing significantly improve diagnostic yield, while pleural biopsy remains the gold standard. Incorporating CB and pleural brushing into routine practice may enable earlier and more accurate diagnosis, particularly in suspected malignant effusions.