Duplication cysts of the alimentary tract usually occur in communication with the gastrointestinal tract and typically share a common wall and blood supply. They are tubular or spherical structures with an epithelium similar to the intestinal tract. Rarely, they occur completely isolated from the gastrointestinal tract with an independent blood supply. That later are referred to as either non-communicating or isolated enteric duplication cysts (IEDC). Here presents the case of a previously healthy eight years old male child, presented to the paediatric surgical clinic with a recent history of severe abdominal pain and vomiting for eleven days. According to the child and his parents, the abdominal pain started insidiously two weeks prior, which was then accompanied by vomiting. The vomiting was initially non-bilious, but later progressed to bilious. Ultrasound of the abdomen showed a cystic abdominal mass. The child was treated conservatively with bowel rest, analgesia and antibiotics. He subsequently opened his bowels and was discharged home. However, he continued to have abdominal pain. On examination the child was able to point at the sight of his pain in the right upper quadrant of the abdomen. A repeat ultrasound scan confirmed a poorly defined, 3.7 cm multiloculated cyst, which was retroperitoneal and abutting on the duodenum superiorly and the inferior vena cava medially. A contrast enhanced CT scan of the abdomen was done. A 2.2 × 3.9 × 2.7 cm (AP x Trans x CC) cyst with contrast enhancing walls was seen closely abutting the inferior vena cava and the junction of the second and third part of the duodenum in the retroperitoneum. However, it did not seem to have any communication with the gastrointestinal tract. At laparotomy, findings included a palpable cystic mass in the root of the mesentery with multiple enlarged lymph nodes. The mesentery however, was freely mobile over the cyst. Therefore, an incision was made lateral to the reflection of the ascending colon and the colon was reflected medially. The cyst was then separated meticulously from the Inferior vena cava medially, the psoas muscle posteriorly and the third part of the duodenum superiorly The specimen was then submitted for histology. Gross examination revealed a cystic mass measuring 3.5 × 2.6 × 2.3 cm, which was multiloculated on cut surface and filled with mucoid fluid. On microscopy, the cyst wall showed organized smooth muscle and a surface simple mucinous columnar epithelium , without goblet cells, suggestive of gastric epithelium. Post operatively, the patient had a smooth recovery. He was discharged the next day and has been asymptomatic for over six months of follow up. This case is to bring attention to this growing number of isolated enteric duplication cysts in the literature. This will help promote the recognition of this pathology as a separate entity in literature as well as research into the etiology, possible early diagnosis and treatment in the future to avoid the probable complications Source: https://www.sciencedirect.com/science/article/pii/S2213576620300415.