BACKGROUND: In patients with intestinal malrotation, the diagnosis of acute appendicitis can be difficult due to atypical presentation. Duodenal obstruction caused by acute appendicitis with the presence of malrotation has rarely been reported in children.

CASE REPORT: We report the case of a 14-year-old male patient with bilious vomiting and abdominal distension. A diagnosis could not be made by computed tomography, ultrasonography, or endoscopy. We observed a dilated stomach and malrotation in laparotomy. The caecum was in the right upper quadrant, and an inflamed appendix was located in the subhepatic region. After the appendectomy, the cecum was mobilized and fixed in the right lower quadrant.

CONCLUSIONS: In children with intestinal malrotation, acute appendicitis can present as duodenal obstruction without abdominal pain, and standard imaging methods can miss the correct diagnosis.

Keywords: Adolescent, Appendicitis - complications, Duodenal Obstruction - surgery, Intestinal Volvulus - surgery