Abstract
BACKGROUND: A combination of diseases is a rare phenomenon. Their clinical manifestations can vary, and the diagnosis can be challenging. Intestinal duplication is a rare congenital malformation, whereas retroperitoneal teratoma is a tumor in the retroperitoneal space, derived from the remaining embryonic tissue. There are relatively few clinical findings on adult retroperitoneal benign tumors. It is hard to believe that these two rare diseases can happen to the same person. CASE SUMMARY: A 19-year-old woman complaining of abdominal pain with nausea and vomiting was admitted. Abdominal computed tomography angiography was suggested for invasive teratoma. Intraoperative exploration revealed that the giant teratoma was connected to an isolated intestinal tract in the retroperitoneum. The postoperative pathological examination revealed that mature giant teratoma was present with intestinal duplication. This was a rare intraoperative finding that was successfully treated surgically. CONCLUSION: The clinical manifestations of intestinal duplication malformation are various, and difficult to diagnose before the operation. The possibility of intestinal replication should be considered when intraperitoneal cystic lesions are present.