Diagnostic Accuracy of Papanicolaou Society of Cytopathology System for Reporting Respiratory Cytology: A Systematic Review and Meta-Analysis.

Introduction: This study conducts the first meta-analysis to evaluate the diagnostic accuracy and the aggregated risk of malignancy associated with each category of the Papanicolaou Society of Cytopathology (PSC) system for reporting respiratory cytology.

Methods: A systematic search was conducted in PubMed, Scopus, and Web of Science using the keywords "(Lung, Respiratory specimens) AND (Papanicolaou Society of Cytopathology System)." Articles were assessed for risk of bias using the QUADAS-2 tool. After excluding inadequate samples, sensitivity and specificity for various cut-off points. Summary receiver operating characteristic curves and diagnostic odds ratios were pooled to assess diagnostic accuracy.

Results: Five studies, totaling 3,489 cases, were included. Sensitivity and specificity for the "Atypical and higher risk categories" considered positive were 60% (95% CI, 51-68%) and 87% (95% CI, 81-92%), respectively. For the "Suspicious for malignancy and higher risk categories" considered positive, sensitivity and specificity were 49% (95% CI, 40-58%) and 95% (95% CI, 92-97%), respectively. Sensitivity and specificity for the "Malignant" category considered positive for malignancy were 42% (95% CI, 33-52%) and 97% (95% CI, 92-99%), respectively. The pooled area under the curve ranged from 68 to 75% for each cut-off.

Conclusion: This meta-analysis underscores the PSC system's accuracy in reporting respiratory cytology. It highlights the diagnostic importance of the "Suspicious" and "Malignant" categories in identifying malignancy, and the utility of the "Atypical" category for initial screening. These findings support the PSC system's role in enhancing diagnostic accuracy and clinical decision-making in respiratory cytology.