Transthoracic needle biopsy of the hilum and mediastinum.

TNB of hilar and mediastinal masses is both safe and useful. It has a high diagnostic yield, can be performed in practically all areas of the mediastinum, and appears to be no more hazardous than needle biopsy of the lung. In healthy patients, it can be performed as an outpatient procedure. TNB makes it possible to avoid surgery and mediastinoscopy in patients with unresectable malignant neoplasms and in many patients with innocuous benign mediastinal lesions. The ease and safety of TNB may make it the preferred initial procedure for diagnosing and staging patients with mediastinal masses of unknown etiology.