Rapid Diagnosis of Mediastinal Tuberculosis with Polymerase Chain Reaction Evaluation of Aspirated Material Taken by Endobronchial Ultrasound–Guided Transbronchial Needle Aspiration

Abstract

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a diagnostic method for tuberculosis (TB). This study was conducted to determine the efficiency of polymerase chain reaction (PCR) testing for detecting TB lymphadenitis in samples obtained by EBUS-TBNA. MATERIALS AND METHODS: A total of 93 consecutive patients with hilar/mediastinal lymphadenopathies and diagnosed with granulomatous diseases through histopathological evaluation were included in the study. The specimens provided by EBUS-TBNA were evaluated through pathological, microbiological, and molecular tests. RESULTS: Eighty-nine (95.7%) of the 93 patients had histopathologically granulomatous diseases by EBUS-TBNA. Tuberculosis was diagnosed in 27 (30.3%) patients and sarcoidosis was diagnosed in 62 (69.7%) patients. Four (4.3%) patients were diagnosed through mediastinoscopy. Endobronchial ultrasound-guided transbronchial needle aspiration had an overall diagnostic efficiency in TB of 96.9%, a sensitivity of 90.9%, and a specificity of 100%. Mycobacterium tuberculosis PCR was positive in 17 of the 30 patients. The sensitivity of PCR was 56.7%, the specificity was 100%, and the general efficiency of the test was 96.4%. CONCLUSIONS: As a result, the use of M. tuberculosis PCR in the EBUS-TBNA specimens provides a rapid and an accurate diagnosis of TB. Therefore, we recommend the use of M. tuberculosis PCR in the EBUS-TBNA specimens as a rapid diagnostic method for mediastinal lymphadenopathies in patients with suspected TB.