Evaluating the role of cytology in diagnosing primary lung carcinoma with special reference to the 2023 WHO lung cytology reporting categories

Abstract

Diagnosing lung carcinoma in cytology specimens is notably challenging. In response, the World Health Organization (WHO) introduced reformulated categories in 2023 that reflect varying malignancy risks. To evaluate this revised classification, it is vital to correlate cytological results with biopsy findings. In this study, we reclassified previously diagnosed cases based on the new WHO cytological categories. Prospective cross-sectional study evaluated cytology samples from lung carcinoma patients at AIIMS Raipur (2019–2021) and, in 2024, reclassified them according to updated WHO categories, facilitating a new assessment of cytology sensitivity through descriptive statistics and calculations. In this study, 116 biopsy-confirmed primary lung carcinoma cases underwent cytological evaluation, with cell blocks prepared for 70 cases. Sample types included bronchoalveolar lavage (BAL) fluid (68 cases, 58.6 %), sputum (4 cases, 3.4 %), and fine needle aspiration cytology (4 cases, 3.4 %); remaining samples were pleural fluid, which were subsequently excluded. Following the adoption of new WHO classification categories in 2024, a retrospective analysis demonstrated a significant improvement in sensitivity, increasing from 36.8 % (28/76) to 65.8 % (50/76), which enhanced the detection of atypical, suspicious, or malignant cases. This study underscores the effectiveness and limitations of cytological examination in diagnosing primary lung carcinoma, demonstrating that many cases can be accurately identified. The new WHO cytology categories improve diagnostic accuracy, but sensitivity results suggest room for precision enhancement. BAL fluid's low sensitivity for peripheral lesions underscores the need for alternative sampling methods.