Chylolymphatic mesenteric cyst with midgut volvulus in an adolescent: a peculiar presentation.

Mesenteric cysts are rare intra-abdominal masses in the pediatric population, with the chylolymphatic variant comprising only 7.3% of all abdominal cysts. These cysts can have a varied clinical presentation, ranging from asymptomatic cystic masses to intestinal obstruction. We report a 16-year-old female, who presented with acute abdominal pain and vomiting, and was diagnosed with an intra-abdominal cystic mass with midgut volvulus accompanied by the classical "whirlpool sign" on imaging. She underwent laparoscopic abdominal exploration, which revealed a large chylolymphatic mesenteric cyst associated with feeder lymph vessels. This cyst had resulted in volvulus of the small bowel. The bowel was detorsed and found to be viable, and the cyst was removed en bloc after suction evacuation with ligation of the lymphatic feeder vessels. Midgut volvulus in the pediatric population is usually secondary to malrotation, but in this case the patient's small intestine was not found to be malrotated, and hence we present this case and urge physicians to consider a diagnosis of midgut volvulus even in the absence of malrotation in a child with a cystic abdominal mass presenting as intestinal obstruction.