Background: Diagnosis of intrathoracic masses is a difficult challenge for clinicians. The compact anatomical arrangement of the mediastinum with diverse pathologies is usually encountered. The present study was done to determine the efficiency of computed tomography (CT) guided Fine-Needle Aspiration Cytology (FNAC) in the evaluation of various thoracic mass lesions

Methods: A total of n=46 patients presenting as intrathoracic mass lesions, confirmed on contrast-enhanced CT, were included in the study. A commercially available CT (Ingenuity 128 slices, Philips) was used for biopsy. All patients were subjected to detailed clinical history and physical examination. Investigations: Complete blood count, Erythrocyte sedimentation rate, bleeding time, clotting time, Prothrombin time, Activated partial thromboplastin time, HIV and HbsAg, Chest X-ray postero Anterior view, and Lateral view done in all cases. Chest X-ray AP view and Ultrasound was done wherever needed. Plain and contrast CT was done in all cases before FNAC.

Results: The positive diagnostic yield in our study is noted in 45 of the 46 patients(97.82%); the positive yield for malignancy was 89.13% (41 of 46 patients), benign in8.69 % (4/46), and undiagnosed in 1/46 (2.17%). Out of 46, 40(86.96%) were parenchymal lesions and 6(13.04%) were mediastinal lesions. Out of 40 parenchymal lesions, 38/40(95%) were malignant, which consisted of 55.3% Squamous cell carcinoma, 28.9% Adenocarcinoma.

Conclusion: FNAC is useful for obtaining samples for the diagnosis of focal pulmonary infections, even in immunocompromised patients, and planning appropriate chemotherapy options in lung cancer and metastatic lesions.CT-guided FNAC is an initial approach for the diagnosis of small pulmonary nodules of less than 20mm, aiding in early diagnosis and treatment interventions improving prognosis.