Patients are often referred for E(B)US examination and sampling of enlarged mediastinal and/or hilar lymph nodes that are not visible on a standard chest X-ray but are discovered by accident on CT scan performed outside the context of lung cancer or extrathoracic malignancies. Since CT scan is largely used and E(B)US is a minimally invasive technique, these cases are explored more frequently but so far nothing is known, however, on the prevalence of abnormal findings in EBUS sampling in this particular population and on the clinical implications (mainly therapeutical implications) of E(B)US findings.

The primary aim is to assess the nature and prevalence of abnormal findings in samplings obtained during E(B)US-NA in the non-cancer patient with CT enlarged mediastinal/hilar lymph nodes that are not visible on chest X-ray. As secondary aims, the clinical implications of E(B)US-NA findings will be assessed, in particular the number of cases where a specific treatment is initiated.

Inclusion Criteria:

• Patient referred to bronchoscopy for tissue diagnosis of discrete enlarged (≥10mm short axis diameter) mediastinal/hilar lymph nodes on CT scan that can be sampled by E(B)US-NA.

Exclusion Criteria:

• Abnormal chest X-ray showing hilar/mediastinal lymph nodes
• Patients with suspected lung cancer
• Patients with previous malignancy diagnosed and definitely treated less than 5 years previously or, if treated more than five years before but with subsequent evidence of recurrence less than 5 years previously.
• Patient with concomitant (suspected or confirmed) bronchopulmonary infection or treated with antibiotics within the 4 previous weeks
• Patients with a contraindication for bronchoscopy and tissue sampling