Real-time prediction of mediastinal lymph node malignancy by endobronchial ultrasound

Abstract

ObjectiveTo evaluate the utility of different ultrasonographic (US) features in differentiating benign and malignant lymph node (LN) by endobronchial ultrasound (EBUS) and validate a score for real-time clinical application. MethodsA total of 208 mediastinal LNs acquired from 141patients were analyzed. Six different US criteria were evaluated (short axis ≥10mm, shape, margin, echogenicity, central hilar structure [CHS], and presence of hyperechoic density) by two observers independently. A simplified score was generated where the presence of margin distinction, round shape and short axis ≥10mm were scored as 1, and heterogeneous echogenicity and absence of CHS were scored as 1.5. The score was evaluated prospectively for real-time clinical application in 65 LNs during EBUS procedure in 39patients undertaken by two experienced operators. These criteria were correlated with the histopathological results and the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. ResultsBoth heterogenicity and absence of CHS had the highest sensitivity and NPV (≥90%) for predicting LN malignancy with acceptable inter-observer agreement (92% and 87% respectively). On real-time application, the sensitivity and specificity of the score >5 were 78% and 86% respectively; only the absence of CHS, round shape and size of LN were significantly associated with malignant LN. ConclusionsA combination of different US criteria can be useful for the prediction of mediastinal LN malignancy and valid for real-time clinical application.