Objective: To analyze the cytological findings of CT-guided percutaneous fine-needle aspiration biopsies of the lung, to demonstrate the diagnostic feasibility of the method in the investigation of pulmonary lesions, and to determine the complications of the procedure, evaluating its safety. Methods: A retrospective analysis of 89 patients with various types of pulmonary lesions who underwent 97 procedures over a period of five years. The patients were divided into groups regarding the indication for the procedure: suspicion of primary lung cancer (stages IIIB or IV); suspicion of lung cancer (stages I, II, or IIIA) and clinical contraindications for surgery; suspicion of pulmonary metastasis from other organs; and pulmonary lesions with benign radiological aspect. All of the procedures were performed with 25-gauge needles and were guided by spiral CT. The final diagnosis was confirmed by surgical biopsy and clinical/oncological follow-up. For the analysis of complications, the total number of procedures was considered. Results: The main indication for the procedure was suspicion of advanced-stage primary lung cancer. The accuracy of the method for malignant lesions was 91.5%. The lesion was confirmed as cancer in 73% of the patients. The major complication was pneumothorax (27.8%), which required chest tube drainage in 12.4% of the procedures. Conclusions: The principal indication for CT-guided fine-needle biopsy was suspicion of primary lung cancer in patients who were not surgical candidates. The procedure has high diagnostic feasibility for malignant pulmonary diseases. The most prevalent complication was pneumothorax. However, in most cases, chest tube drainage was unnecessary. No deaths were related to the procedure.

Keywords: Biopsy, fine-needle; Tomography, spiral computed; Lung neoplasms; Pneumothorax.