RESUMEN
Primary retroperitoneal mucinous cystadenoma is an extremely uncommon tumor, even though mucinous cystadenoma often develops in the ovary and less frequently in the pancreas. A 21-year-old female was admitted to our hospital due to severe abdominal pain. A well-demarcated, oval shaped cystic tumor at the retropancreatic area with displacement of the pancreas and surrounding major vessels was observed on CT and MRI. Exploratory laparotomy was performed, and complete excision of the entire cyst was performed without complication. The pathologic finding was consistent with primary retropancreatic mucinous cystadenoma. To the best of our knowledge, this report is the first to describe a case of retropancreatic mucinous cystadenoma arising from the retropancreatic area in Korea.