The Role of EBUS-TBNA for the Diagnosis of Sarcoidosis

Abstract

PURPOSE: Transbronchial and endobronchial biopsies are recommended as initial procedures for the diagnosis of pulmonary sarcoidosis. After emerging EBUS-TBNA, the diagnosis of indeterminate mediastinal lymph nodes with clinical suspicious of sarcoidosis might be challenging. In this report, we analyze the accuracy of EBUS-TBNA in the diagnosis of sarcoidosis and the influence of different factors in the diagnostic yield. METHODS: We reviewed the cytopathologic reports of a series of 49 cases of benign Lymph nodes in which diagnosis was performed by EBUS. All patients had enlarged hilar and/or mediastinal LN in chest CT. We performed EBUS-TBNA under conscious sedation with 21 or 22 G needle and with or without ROSE. The gold standard was the histological study of lymph nodes made by mediastinoscopy if the results of EBUS-TBNA were negative. RESULTS: EBUS-TBNA confirmed a diagnosis of sarcoidosis in 28 of the 49 patients (57%) by identifying non-caseating epitheliod cell granulomas. The remaining 21 patients were diagnosed by mediastinoscopy, 10 patients as sarcoidosis and 9 patients as non-specific benign LN. None of these patients had a high clinical suspicion of sarcoidosis. So, the diagnostic yield in patients with clinical suspicious of sarcoidosis was higher than in patients without it (66% vs 27%). The sensitivity of EBUS-TBNA was 74% and the diagnostic accuracy was 79%. ROSE did not improve the diagnostic yield but the results were better with 21G needle than with 22G needle (75% vs 54%). The mean size of the enlarged LN, as measured by EBUS, was 12.8 mm, and higher in sarcoidosis LN than non-sarcoidosis LN (15.3 mm vs 11.5 mm). CONCLUSIONS: EBUS-TBNA is a useful tool for diagnosis of sarcoidosis and might be the first step in the diagnosis of sarcoidosis if hilar LN are present. The pre-test probability is an important influence in the diagnostic yield of EBUS for the diagnosis of sarcoidosis.