Laparoscopic Resection of a Giant Completely Isolated Intestinal Duplication Cyst in a Child.

Introduction: Completely isolated intestinal duplication cysts are rare congenital lesions that lack continuity with the gastrointestinal tract and have an independent vascular pedicle. Their presentation beyond infancy and distinction from mesenteric or omental cysts can be challenging, particularly when only noncontrast imaging is available. Case Description: We report the laparoscopic resection of a giant isolated intestinal duplication cyst in a 10-year-old boy who presented with abdominal distension and pain. Noncontrast computed tomography demonstrated a large cystic lesion occupying the pelvis and lower abdomen, initially interpreted as a mesenteric cyst. Laparoscopic exploration revealed a giant unilocular cyst without macroscopic communication with the bowel, supplied by a single vascular pedicle traversing the diaphragm from the thoracic cavity. The pedicle was clipped and divided, and the cyst wall was completely excised and retrieved in an endoscopic specimen bag without intestinal resection. Histopathologic examination showed a fibrous cyst wall with a well-organized double layer of smooth muscle and complete mucosal ulceration replaced by chronic inflammatory granulation tissue with multinucleated giant cells and cholesterol clefts, consistent with an enteric inclusion (duplication) cyst. The postoperative course was uneventful, and the patient remained asymptomatic at two months of follow-up. Discussion: This case illustrates that completely isolated intestinal duplication cysts may present in older children and mimic mesenteric cysts, and that laparoscopic resection allows definitive diagnosis while preserving intestinal continuity.