Ultrathin needle (25 G) aspiration lung biopsy: diagnostic accuracy and complication rates.

The aim of this study was to evaluate the diagnostic accuracy and complication rate of 25-G fine-needle aspiration biopsy (FNAB) of the lung in patients with suspected malignant focal lesions and abnormal lung function. The 25-G FNAB was performed in 123 patients who underwent prebiopsy CT and pulmonary function tests. Retrospective evaluation included pulmonary function, cytology, size of the lesion, depth of location, presence of emphysema on CT, needle passes, pneumothorax and drainage. The final diagnosis (gold standard) was based on histopathology after surgical resection or follow-up and response to treatment. Sixty-one patients had normal lung function or mild impairment (group 1) and 62 had moderate or severe impairment (group 2). Pneumothorax occurred in 26 of 126 procedures (20.6%) with drainage needed in 11 (8.7%). In group 2 pneumothorax occurred in 19 of 63 procedures (30.15%) with drainage needed in 11 (17.5%). The sensitivity, specificity and diagnostic accuracy of cytology results were 93.6, 100 and 94.4%, respectively. FEV1 ( p=0.014), FEV1/FVC ( p=0.005), FEF25-75 ( p=0.001), DLCO ( p=0.013) and presence of emphysema on CT ( p<0.001) correlated with pneumothorax (Student's t test). The 25-G lung FNAB is accurate and safe in diagnosing malignancy in patients with severe lung functional abnormality. Patients with moderate to severe airway obstruction have a higher prevalence of pneumothorax than patients with mild or no functional impairment.