Superior herniation of the mediastinum presenting as an anterior neck mass on straining.

We report an infant with an anterior neck mass present only on straining. Airway fluoroscopy revealed this to be due to superior mediastinal herniation. Neck masses apparent only during Valsalva maneuver are rare and awareness of the differential diagnosis is important to avoid unnecessary investigation or surgery. Pediatr Pulmonol. 2012; 47:710–712. © 2012 Wiley Periodicals, Inc.