CT presentation of ruptured appendicitis in an adult with incomplete intestinal malrotation.

Intestinal malrotation is defined anatomically as a developmental anomaly. It may cause atypical clinical symptoms in relatively common intestinal disorders because of the altered anatomy. A 64-year-old man presented with acute mid-abdominal pain. Underlying incomplete malrotation prevented the correct clinical diagnosis of ruptured appendicitis. Computer tomography demonstrated typical signs of malrotation, i.e., right-sided duodenojejunal junction, left position of cecum, inverted position of the superior mesenteric vessels, and pathology revealed a ruptured appendix with an abscess and a coincident mucinous cystadenoma.