The 'wandering appendicolith'.

Acute appendicitis is a common pediatric surgical emergency. Successful surgical appendectomy requires removal of the appendix and its contents. A retained appendicolith is a complication that occurs when the appendicolith is expulsed from the appendix as a result of perforation or failure of removal during surgery. An ectopic appendicolith can migrate to a variety of ectopic locations, acting as a nidus for abscess. Clinical presentation may be delayed by days, weeks or even months after surgery. We present and discuss an unusual case of empyema caused by migration of an appendicolith into the chest cavity. Management of these retained appendicoliths requires drainage of the abscess and extraction of the appendicolith.