RESUMEN
Duplication cysts are rare congenital abnormalities of the alimentary tract, typically manifesting symptoms in the first 2 years but uncommon in adults. Medical data on duplication cysts is scarce in Vietnam's Mekong Delta region. These two adult cases aim to provide fundamental knowledge, clinical characteristics, diagnosis, risks, complications, surgical and observational treatment methods, and future bilateral tumor research. Case 1: A 21-year-old male with intestinal obstruction symptoms. Computed tomography (CT)-scan revealed a strangulated small bowel obstruction with ischemia. Laparotomy discovered a twisted ileal duplication cyst causing necrosis in ~30 cm of the small intestine. Case 2: A 34-year-old woman hospitalized for right lower quadrant pain. CT-scan showed a cystic structure protruding into the ascending colon lumen. She underwent a laparoscopic right hemicolectomy, and an ascending colonic cyst was found in the specimen. Conclusions: Duplication cysts are rare anomalies, especially in adults. Comprehending and acquiring knowledge ensures prompt diagnosis and appropriate treatment.