Value of endobronchial ultrasound-guided transbronchial needle aspiration in diagnosis of the mediastinal enlarged lymph nodes

Abstract

Objective: To investigate the value of the endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in diagnosing mediastinal enlarged lymph nodes. Methods: A total of 210 patients with mediastinal enlarged lymph nodes from the First Affiliated Hospital of Zhengzhou University from 2014 July to 2015 October were enrolled for EBUS-TBNA. Endobronchial ultrasound (EBUS) imaging features, including lymph node short diameter, the ratio of longitudinal to transverse diameter, the blood flow and morphology destroy, in benign and malignant lymph nodes were evaluated separately and their relationships with the rate of malignant lymph nodes were also analyzed. The significant variables according to single factor analysis were brought into the Logistic multivariate analysis, which investigated the risk factors of malignant lymph nodes. The best cut-off point of the short diameter of lymph nodes was analyzed by receiver operating characteristic curve (ROC). The sensitivity, specificity and accuracy of EBUS-TBNA in the diagnosis of malignant lymph nodes were analyzed by the standard calculation formula. Results: The sensitivity, specificity, accuracy rate of EBUS-TBNA diagnosing lung cancer and other tumor with mediastinal lymph node metastasis were 91.2%, 100%, 93.8%. The rates of malignant in lymph node with short diameter ≥1.0 cm, ratio of longitudinal to transverse diameter<1.5, blood flow distribution Ⅱ-Ⅲ, morphology destroy by the EBUS measurement were higher than those in the lymph node with short diameter<1.0 cm, ratio of longitudinal to transverse diameter ≥ 1.5, the blood flow distribution 0-Ⅰ, without morphology destroy (79.8%, 77.8%, 84.7%, 76.7% vs 37.7%, 44.6%, 42.9%, 42.9%), and the four factors were independent risk factors for malignant lymph nodes (all P<0.001). The ROC curve indicated the optimal cut-off point of short diameter was 8.2 mm. The accuracy of diagnosis by the combination of the above 4 ultrasound features, those were the lymph node short diameter not less than 1 cm, the ratio of longitudinal to transverse diameter less than 1.5, the blood flow distribution Ⅱ-Ⅲ and morphology destroy, was higher than those of the single factor (89.3% vs 74.7%, 67.9%, 67.8%, 67.5%) (all P<0.001). Conclusion: EBUS-TBNA has satisfying value in diagnosing malignant mediastinal enlarged lymph nodes.