Endobronchial ultrasound diagnostic yield for sarcoidosis in hilar vs. mediastinal lymph nodes.

Background: Pulmonary sarcoidosis is diagnosed by endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA) of hilar and mediastinal lymph nodes and the finding of non-caseating granulomatous inflammation. There are currently no guidelines about which lymph node stations to sample to optimize the diagnostic yield and it is unclear if there is a difference in the yield between hilar and mediastinal lymph node stations. The objective of this study was to assess the difference in the diagnostic yield of EBUS-TBNA for non-caseating granulomas between hilar and mediastinal lymph nodes. Methods: A retrospective study was performed and medical records were reviewed of all patients at a single institution who underwent EBUS-TBNA of thoracic lymph nodes to evaluate for sarcoidosis. Results: Two hundred twenty-five patients with suspicion of sarcoidosis underwent EBUS-TBNA for evaluation of hilar and mediastinal lymphadenopathy. The yield of EBUS-TBNA for non-caseating granulomas was 61.8% vs. 65.5%, P=0.46, for hilar and mediastinal lymph nodes, respectively. The sensitivity for sarcoidosis of EBUS-TBNA of hilar vs. mediastinal nodes was 66.9% [95% confidence interval (CI): 58.9-74.9%] vs. 71.1% (95% CI: 65.3-76.9%). The specificity for sarcoidosis of EBUS-TBNA of both hilar and mediastinal nodes was 100%. The diagnostic yield for non-caseating granulomas in patients who underwent hilar nodes biopsy only, mediastinal nodes biopsy only, and both hilar and mediastinal nodes biopsy was 71.4%, 67%, and 73.1%, respectively (P=0.63). In multivariable logistic regression analysis, the diagnostic yield of EBUS-TBNA was only associated with age [odds ratio (OR) 0.96; 95% CI: 0.94-0.98; P<0.01]. Conclusions: The yield of EBUS-TBNA for non-caseating granulomas in patients with suspected sarcoidosis was similar between the hilar and mediastinal lymph nodes.