A study to determine etiological factors behind pulmonary mass lesions in patients attending Respiratory Medicine Department, RIMS, Imphal

Background: A Pulmonary mass lesion is a common finding on Chest X-ray and CT thorax scans. Theselesions can be benign or malignant. Early tissue diagnosis is crucial for the proper management of theselesions. The study aimed to determine the etiological profile of pulmonary mass lesions and compare thediagnostic yield of USG/CT-guided transthoracic FNAC and bronchoscopic procedures in a tertiary caresetting.Methods: This was a cross-sectional study carried out in the Department of Respiratory Medicine at aRIMS, Imphal, from March 2024 to February 2026. Fifty-eight consecutive patients with pulmonary masslesions underwent subsequent diagnostic modalities, including Transthoracic FNAC and/or bronchoscopicprocedures (BAL, EBB, TBNA, TBLB). Fisher’s exact test, Chi-square test, and descriptive statistics wereused to examine the data; p-values less than 0.05 were deemed statistically significant.Results: The mean age was 69.7 ± 11.6 years with female predominance (58.6%). Malignancy was themost common etiology (84.5%), while benign lesions accounted for 12.1% and 3.4% were inconclusive.Squamous cell carcinoma (42.9%) was the predominant malignancy, followed by adenocarcinoma (34.7%)and small cell carcinoma (18.4%). Tuberculosis was the leading benign cause. FNAC had a diagnostic yieldof 93.5%, and bronchoscopic procedures were successful in 94.3% of cases. Diagnostic yields werecomparable descriptively; however, the paired subgroup was too small (N =8) for formal comparativestatistical analysis.Conclusion: Pulmonary mass lesions are predominantly malignant, with tuberculosis being the leadingbenign etiology. Both FNAC and bronchoscopic procedures demonstrated high, complementary diagnosticyields, though the paired subgroup was too small for formal comparative statistical analysis.