Nonsurgical staging of the mediastinum: EBUS and EUS

A tissue diagnosis is frequently needed for accurate lung cancer staging of mediastinal nodes as well as the assessment of mediastinal masses. Noninvasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), positron-emission tomography (PET), and PET-CT provide some answers but no tissue diagnosis. Transbronchial needle aspiration (TBNA), a safe procedure that is performed during routine bronchoscopy, has a high impact on patient management. Unfortunately, TBNA remains underused in current daily practice, mainly due to the lack of real-time needle visualization. The introduction of echo-endoscopes has overcome this problem. Endobronchial ultrasound-guided TBNA (EBUS-TBNA) allows real-time controlled tissue sampling of paratracheal, subcarinal, and hilar lymph nodes. Mediastinal lymph nodes located adjacent to the esophagus can be assessed by esophageal ultrasound-guided fine needle aspiration (EUS-FNA). Owing to the complementary reach of EBUS-TBNA and EUS-FNA in assessing different regions of the mediastinum, recent studies suggest that complete and accurate mediastinal staging can be achieved by the combination of both procedures. It is expected that implementation of minimally invasive endoscopic methods of EBUS-TBNA and EUS-FNA will reduce the need for surgical staging of lung cancer significantly.