Background: CT guided percutaneous transthoracic fine needle aspiration (FNA) and core biopsy (CB) are commonly used to characterise lung lesions. There is conflicting information on which method is superior and wide variation in reported complication rates.

Objectives: Our objectives were to establish the efficacy and safety of percutaneous CT guided FNA and CB in the diagnosis of malignant lung lesions.

Methods: This retrospective study included patients who underwent CT guided percutaneous FNA and/or CB for lung parenchymal lesions at Kasturba Medical College Mangalore from January 2013 to December 2020. Ethical clearance was obtained from the Institutional Ethics Committee. Efficacy was determined by the adequacy of samples, sensitivity, specificity and diagnostic accuracy. Safety was assessed using the incidence of complications.

Results: 326 patients underwent both FNA and CB, and 49 underwent FNA alone. Adequate samples were obtained in 82.9% of FNA cases and 95.7% of CB cases. Considering biopsy as the gold standard, the sensitivity, specificity and diagnostic accuracy of FNA for malignancy were 95.19%, 80% and 91.27%, respectively. Kappa agreement between the two methods was substantial (0.767). Pneumothorax was the only complication observed, and was seen in 31 patients (8.2%), of which only one required chest tube drainage. The incidence of pneumothorax was significantly higher in patients with pre-existing lung disease such as COPD/emphysema (p value 0.000), patients with smaller lesions (p = 0.009), and deeper lesions from the pleura (p <0.0001).

Conclusions: FNA and CB are both safe and effective procedures. In the absence of an onsite cytopathologist, we recommend a combination of both techniques.

Hospital based retrospective record review.