Identification of specific EBUS sonographic characteristics for predicting benign mediastinal lymph nodes.

Abstract

Reliable differentiation of benign from malignant mediastinal lymphadenopathy is important, especially in countries with a high tuberculosis burden. We hypothesized that specific sonographic features on endobronchial ultrasonography (EBUS) may differentiate benign from malignant nodes. In this study, the sonographic features of non-malignant and malignant nodes were compared. This was a retrospective analysis of patients with intrathoracic lymphadenopathy who underwent EBUS-guided transbronchial needle aspiration (TBNA). Sonographic features such as nodal size, margin (distinct or indistinct), echogenicity (heterogeneous or homogeneous), and presence or absence of calcification, a central hilar structure, coagulation necrosis sign, and nodal conglomeration were recorded and compared in the 2 groups. During the study period, a diagnosis of tuberculosis (n = 71), sarcoidosis (n = 63), and malignancy (n = 36) was made in 170 patients by EBUS-TBNA. A total of 312 lymph node stations were examined. Presence of central hilar structure (15.6% versus 4%, P = .03) and the presence of nodal conglomeration (27.5% versus 8%, P < .01) were significantly higher in benign nodes. Further, logistic regression analysis revealed that the presence of well-defined nodal margins, the presence of central hilar structure, and the presence of conglomeration of lymph nodes were independent predictive factors for the diagnosis of benign mediastinal lymphadenopathy. Sonographic features of well-defined margins, presence of central hilar structure, and presence of nodal conglomeration in the lymph nodes on EBUS are predictive of benign disease.