Unusual duplication of appendix and cecum: extension of the Cave-Wallbridge classification.

Duplicated appendix has, to date, been classified into 3 types. The authors present a type of duplicated appendix not previously described. Surgical exploration was done in a 14-year-old girl who had an acute abdomen. Surgical exploration showed a duplicated appendix that arose from the normal appendix and ended in a thick-walled, inflamed, perforated muscular pouch. Duplicated appendix is a treatable condition that rarely occurs with colonic duplication and which should be considered in the differential diagnosis of lower abdominal pain.