This is an observational prospective study. Role of EBUS-TBNA (endobronchial ultrasound transbronchial needle aspiration) is evaluated to diagnose tuberculosis in mediastinal and/or hilar lymph nodes.

The investigators analyse the specificity and sensibility of this technique to diagnose tuberculosis in mediastinal and/or hilar lymph nodes.

Patients with mediastinal and/or hilar lymph nodes on X-ray or CT thorax where a tuberculosis is the most probable cause and who have no parenchymal lesions suspected for tuberculosis and without other lymph nodes that are more easily accessible or palpable will be included in this study.

Inclusion Criteria:

• patients with enlarged mediastinal and/or hilar lymph nodes on chest CT highly suspicious of tuberculosis (suggestive clinical history, suggestive echographic findings ...) without pulmonary lesions suspicious for tuberculosis or in whom the first evaluation with sputum examination, classical bronchoscopy, induced sputum didn't result in any diagnosis.
• patients aged 18 years or older
• patients need to sign the consent form after reading the information form

Exclusion Criteria:

• synchronic pulmonary lesions suspicious for tuberculosis or already proven tuberculosis by microscopic exam, PCR-technique and/or culture
• other affected ganglionary sites more easily accessible (cervical, supraclavicular, axillary ... region)