Extraluminal appendicolith: an indication for interval appendectomy with intraoperative localization and removal of that potential cause of intra-abdominal abscess

Appendicoliths are formed by calcium salts and fecal debris layered and lodged within the appendix. They are detected on unenhanced X-rays in <10% of patients with appendicitis. When an appendicolith is found extraluminally, it is pathognomonic for perforation of the appendix. Moreover, retained appendicoliths are likely to be infected and to be the source of a postoperative intraperitoneal abscess, whereupon the only definitive treatment is surgical excision. In this paper, we describe an asymptomatic patient with evidence of an extraluminal appendicolith on computed tomography following successful conservative treatment for a periappendicular abscess. She underwent a laparoscopic interval appendectomy that included the removal of an extraluminal appendicolith and was released home on the following day. We advocate this approach in order to prevent the possible formation of an intra-abdominal abscess caused by an infected nidus.