Perforated duodenal diverticulum successfully diagnosed preoperatively with abdominal CT scan associated with upper gastrointestinal series.

Although duodenal diverticulum is not uncommon, precise preoperative diagnosis is occasionally difficult. We report a patient with perforated duodenal diverticulum successfully diagnosed preoperatively by an upper gastrointestinal series followed by abdominal computed tomography (CT) scanning. An 81-year-old Japanese woman visited a local hospital because of right-sided abdominal pain. Physical examination revealed diffuse muscle guarding localized in the entire right-side of the abdomen indicative of peritonitis. While plain abdominal X-ray film revealed no free air, abdominal ultrasound and abdominal CT scanning revealed fluid collection and gas in the anterior perirenal space. An emergency upper gastrointestinal series, using water-soluble contrast media, demonstrated multiple diverticula in the descending portion and the horizontal portion of the duodenum. Leakage of the contrast material was found by the upper gastrointestinal series followed by the abdominal CT scanning, suggesting that the peritonitis was caused by the perforated duodenal diverticulum, and an emergency laparotomy was performed. The diverticulum in the descending portion of the duodenum was mobilized from the retroperitoneum and complete resection and peritoneal drainage were performed. The resected specimen showed that the diverticulum was 42 x 23 mm in size, and two separate sites of perforation were identified. The present case suggests that upper gastrointestinal series followed by CT scan is useful for the preoperative diagnosis of perforated duodenal diverticulum.