Reproducibility of “the Papanicolaou Society of Cytopathology system for reporting respiratory cytology” – A retrospective analysis of 101 cases of CT ‐guided FNAC

INTRODUCTION: Guided fine-needle aspiration cytology is a popular investigative procedure in diagnosing pulmonary lesions. The Papanicolaou Society of Cytopathology (PSC) has already outlined a categorical system for reporting respiratory cytology. Though each category has a known malignancy risk, their inter observer reproducibility have not been well documented. This study was directed towards establishing the reproducibility of this categorical system in diagnosing pulmonary lesions. METHOD: One hundred and one consecutive cytology specimens obtained by CT-guided FNA from lung lesions were independently reviewed by 3 experienced cytopathologists, who allotted each case to 1 of 6 PSC categories. Statistical analysis for percent overall agreement was done using Fleiss' Kappa. RESULT: Percent overall agreement was 71.29% and free marginal kappa was 0.66. On combining categories "suspicious" and "malignant" percent overall agreement was 79.54% and free marginal kappa was 0.74. CONCLUSION: There was substantial agreement among the observers as regards reproducibility of categories which can improve if we combine certain categories, especially "suspicious" and "malignant."