Invasive staging of the mediastinum.

Staging of patients with lung cancer provides accurate information on the extent of disease and guides the choice of treatment. Non-invasive imaging techniques are safe, however these imaging techniques have limited accuracy in detection of mediastinal lymph node metastases. The American College of Chest Physicians guidelines for lung cancer staging recommend that patients with abnormal lymph nodes on CT or PET, or centrally located tumors without mediastinal LNs, should undergo invasive staging. Mediastinal nodal sampling has traditionally been performed by cervical mediastinoscopy. However, with the development of endoscopic needle aspiration techniques such as endobronchial ultrasound (EBUS) to guide transbronchial needle aspiration (TBNA) and endoscopic ultrasound (EUS), the diagnostic algorithm for lung cancer is changing.