Fluoroscopy
What is the differential diagnosis for this RLQ cystic structure?
Duplication cyst, mesenteric cyst, Meckle's diverticulum
What is the hypothesized embryological basis for a gastrointestinal duplication cyst?
Several hypotheses exist, but none can explain all duplication cysts. The aberrant luminal recanalization theory can potentially explain the eosophageal, small bowel and colonic duplication cysts, but not those in other locations. The intra-uterine vascular accident theory and the abortive twinning theory have also been proposed.
Fluoroscopy: Fluoroscopic air enema study demonstrating air within the small bowel loops in keeping with a successful reduction. There is a rounded density in the region of the ileocaecal valve, which can be seen in cases of ileocolic intussusception as the intussusceptum appears as a filling defect in this region. However, given that the presence of air in the small bowel loops suggests that the intussusceptum was reduced, this density is likely in keeping the cystic structure seen on ultrasound.