Isolated duodenal duplication cyst presenting as a complex solid and cystic mass in the upper abdomen

Duodenal duplication cysts are a rare subtype of gastrointestinal duplications cysts. Approximately 5% of gastrointestinal duplication cysts occur in the duodenum. An 18-year-old woman presented with epigastric pain and a subjective abdominal bulge. A computed tomography scan was subsequently performed and showed a solid and cystic mass with wall calcifications in the lesser sac of the upper abdomen. A duodenal duplication cyst was found unexpectedly on histopathologic analysis. This was also an unusual case as there was no evidence of malignancy. Four years after surgery, the patient remains asymptomatic. We present a brief literature review on duodenal duplication cysts and discuss its differential diagnosis.