Diagnostic Efficacy of Combined CT Guided Fine Needle Aspiration and Core Needle Biopsy Versus Either Technique Alone in Peripheral Lung Lesions

Background: Precise cytological and histological diagnosis is crucial in the era of targeted therapy for lung lesions. Both Fine Needle Aspiration Cytology (FNAC) and Core Needle Biopsy (CNB) are established diagnostic techniques, yet their individual and combined efficacy remains debated. Objective: To evaluate the diagnostic yield of combined CT-guided FNAC and CNB versus either technique alone in peripheral lung lesions. Methods: This prospective study enrolled 110 patients with undiagnosed peripheral lung lesions at the National Institute of Diseases of Chest and Hospital (NIDCH) during 2023. CT-guided FNAC was performed using a 22-gauge spinal needle, followed by CNB using an 18-gauge Trucut needle in the same setting. Six FNAC smears were prepared and stained with hematoxylin and eosin, while CNB specimens were processed as paraffin-embedded blocks. Results were classified into four categories: inadequate, negative, suspicious, and positive for malignancy. Results: The diagnostic yield of the combined approach was 99.1%, compared to 89.1% for FNAC alone and 98.2% for CNB alone. FNAC showed 85.1% sensitivity while CNB demonstrated 97.7% sensitivity. Both methods achieved 100% specificity and positive predictive value. The negative predictive value was 77.3% for FNAC versus 95.7% for CNB. Among malignant lesions (n=87), CNB provided definitive diagnosis in cases where FNAC showed suspicious findings (10 cases). For benign lesions (n=22), CNB showed superior diagnostic capability, particularly in granulomatous inflammation and chronic pneumonitis. Procedure-related complications were minimal (3.6%) with no major adverse events. Conclusion: Combined FNAC and CNB approach provides superior diagnostic yield compared to either technique alone. While CNB demonstrated higher individual diagnostic accuracy, the combined approach offered maximum diagnostic precision without significantly increasing complications. This strategy is particularly valuable for cases ...