Incidental mucocele of the appendix in a 15-year-old girl.

Mucocele of the appendix is an exceedingly uncommon pathology in the pediatric population that may present with abdominal pain or represent an incidental finding after routine abdominal imaging. Etiologies may be inflammatory or neoplastic, but all share the commonality of chronic appendiceal obstruction. Early diagnosis is critical for positive long-term outcomes because the operative management will differ from that of a dilated appendix secondary to acute appendicitis.