Pneumothorax: a complication of percutaneous aspiration of upper pole renal masses.

Pneumothorax is a rare complication of percutaneous needle aspiration of suspected upper pole renal cysts. This complication is of particular concern in elderly patients with compromised cardiopulmonary reserve who undergo this procedure on an outpatient basis. An upright expiratory chest film is recommended following needle aspiration of upper pole lesions for detection of asymptomatic pneumothorax.