Retroperitoneal abscess associated with a perforated duodenal ulcer.

Retroperitoneal abscess after duodenal ulcer perforation is a rare condition. A 71-year-old woman was admitted with 1 month of appetite loss and back pain. Abdominal computed tomography scan showed a retroperitoneal mass behind the third and fourth portions of the duodenum. Single-balloon enteroscopy revealed erosion of the third portion of the duodenum with leakage of contrast agent into the retroperitoneal space. Based on a preoperative diagnosis of retroperitoneal abscess after duodenal perforation, laparotomy was performed. Partial duodenectomy with a duodeno-jejunal anastomosis was performed, and her postoperative course was uneventful. Pathology showed an ulcer with no specific findings.