Etiology of mediastinal lymph node enlargement in patients who underwent EBUS-TBNA

Introduction: Mediastinal lymphadenopathy (ML), may be caused either by malignant or benign diseases. It usually is diagnosed by chest computed tomography and bronchoscopy with endobronchial ultrasound guided TBNA (EBUS-TBNA). Aim: The aim of the study was to analyze causes of ML in patients, in whom bronchoscopy with EBUS-TBNA was performed. Patients and Methods: A retrospective analysis of all patients, who had ML and underwent bronchoscopy with EBUS-TBNA between 2009 and 2017 was performed. Results: 1075 (596 M, 479 F) patients who underwent EBUS-TBNA were included in the analysis. The most common cause of ML were malignant diseases (n=662, 61.6%). Lung cancer was diagnosed in 572 (53%) patients, while 90 (8.4%) patients had other malignancies. Non-malignant diseases were diagnosed in 356 (33.1%) patients. In this group the most common diagnosis was sarcoidosis -250 patients (23.3%). Infectious diseases were documented in 32 cases (3%) and included: tuberculosis (17), MOTT (2), pneumoniae (10), pulmonary invasive mycosis (2) and mononucleosis (1). In 51 (4.7%) patients ML was associated with heart failure. 23 patients (2.1%) had other diseases that could have explained ML (among them interstitial lung diseases were the most common). In 57 (5.3%) etiology of ML could not have been determined due to lack of pathologic diagnosis or follow-up. Conclusions: The most common cause of ML were malignant diseases. Sarcoidosis and HF accounted for the majority of benign ML causes, while infections only occasionally were diagnosed as the cause of ML.