Abstract: Objective To investigate the value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in early diagnosis of patients with mediastinal tuberculous lymphadenopathy. Methods Eighty-seven patients, who were considered to have mediastinal tuberculous lymphadenopathy based on clinical indications and imaging, but with normal fiber bronchoscope examination results, were recruited in Shanghai Pulmonary Hospital from Jan 2010 to Dec 2012. All enrolled patients underwent EBUS-TBNA, and then samples obtained by EBUS-TBNA were performed pathological examination, smear, culture and PCR, drug susceptibility testing (DST) was performed for all patients with culture-positive. Patients who had negative results with all above mentioned examinations, a standardized diagnostic chemotherapy with 4 first-line anti-TB drugs was given for 3 months; if no improvement on imaging during 3 months, mediastinoscopy was carried out. Software SPSS 13.0 was used for data analysis. Results Sixty-six patients were diagnosed with TB using the samples obtained by EBUS-TBNA: pathological findings were consistent with TB in 38 patients (57.58%, 38/66), microbiological investigations yielded a positive culture of TB and/or positive smear in 21 patients (31.82%, 21/66; identified 3 drug-resistant cases), as well as a positive PCR in 40 patients (60.61%, 40/66); 1 patients was identified as non-tuberculosis mycobacteria (NTM); 5 patients were diagnosed with cancer; 2 patients were diagnosed with sarcoidosis. Thirteen patients did not have a specific diagnosis following EBUS-TBNA: 7 patients underwent mediastinoscopy and TB was confirmed in one, lymphoma was confirmed in 3 and cancer was confirmed in 3; 6 patients who responded to empirical anti-TB treatment were diagnosed with TB. A total of 73 patients were diagnosed as TB in this research and 66 of them (90.41%, 66/73) were diagnosed by EBUS-TBNA. Conclusion EBUS-TBNA may be useful in early diagnosis of mediastinal tuberculous lymphadenopathy, especially to drug-resistant TB. The use of PCR can be helpful for the diagnosis of TB.

Key words: Tuberculosis,lymph node/diagnosis, Mediastinal diseases, Biopsy, Bronchoscopy