Adult intussusception caused by an appendiceal mucocele and reduced by colonoscopy.

Appendiceal intussusception is a very rare disease that is found in only 0.01% of patients who have undergone an appendectomy. Clinical symptoms vary but include acute appendicitis symptoms such as right lower quadrant abdominal pain or repetitive right lower quadrant crampy pain. Some patients are asymptomatic. Operative treatment is necessary to reduce an appendiceal intussusception in adults, but there is a debate about how to perform the reduction. Successful colonoscopic reductions have been recently reported for some cases. We report a case of appendiceal intussusception that was diagnosed, reduced by colonoscopy, and histologically confirmed as a mucinous cystadenoma after the operation.