Background: The diagnosis of the central intrapulmonary lesion is technically challenge. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is useful for diagnosis of mediastinal lesion and staging before lung cancer surgery. The usefulness of EBUS-TBNA for central intrapulmonary lesion will be evaluated.

Objective: To evaluate the diagnostic performance and safety of convex probe endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of central intrapulmonary lesion and the usefulness of rapid on-site evaluation for samples taken during EBUS-TBNA.

Materials and Methods: The present prospective cross-sectional study was conducted to enroll 175 patients with central intrapulmonary lesions underwent EBUS-TBNA at Vachira Phuket Hospital from June 2013 to May 2017. The diagnostic yield, sensitivity, specificity, PPV, NPV, diagnostic accuracy and associated factors were analyzed.

Results: EBUS-TBNA was performed to 175 patients with central intrapulmonary lesion. The overall diagnostic yield of EBUS-TBNA was 90.3%. The diagnostic yield in the benign lesion was 82.1% and malignant lesion was 91.8%. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy for detecting intrapulmonary lesion were 91.8%, 100%, 100%, 70%, and 91.4%, respectively. Rapid on-site evaluation (ROSE) was available in 52 patients. ROSE was the most important factor that helped enhance EBUS-TBNA diagnostic accuracy (p = 0.005). A logistic regression analysis revealed that heterogenous echogenicity and ill-defined margin from EBUS image were predictive factors for malignant lung lesion with the hazard ratio of 26.136 (p<0.001) and 3.947 (p = 0.001), respectively. The availability of ROSE resulted in a significant reduction in the number of passes per lesion (mean: 3.40±0.66 vs 6.07±1.34, p<0.001) and the duration of procedure (mean: 32.33±6.50 vs 50.32±4.99, p<0.001). The cytologic result from ROSE was false negative in 2 samples with the sensitivity and specificity were 92% and 100%, respectively.

Conclusion: EBUS-TBNA is an effective and safe procedure for the diagnosis of central intrapulmonary lesion not visible by conventional bronchoscopy. It is minimally invasive and improves the diagnostic performance.

Keywords: Endobronchial ultrasound-guided transbronchial needle aspiration, Central intrapulmonary lesion, Rapid on-site evaluation, Convex probe endobronchial ultrasound