RESULTS: A total of 86 patients (53 males and 33 females; average age, 52.4±4.8 years) with UPE were enrolled. 90.7% and 94.2% procedures of CNB and SPB provided adequate material for histological analysis. The sensitivity, specificity, PPV, NPV and diagnostic accuracy of US-guided CNB were 70.7%, 100%, 100%, 75.5%, 84.6%, respectively; the corresponding values for SPB were 68.3%, 100%, 100%, 75.5%, 84.0%, respectively; while the values for combination of CNB and SPB were 92.7%, 100%, 100%, 93.6% and 96.5%, respectively. Combination of CNB and SPB significantly improves sensitivity, specificity and diagnostic accuracy when compared to each individual technique (P < 0.001). An asymptomatic pneumothorax was present in one patient with no chest tube placement required.