[Accurate, preoperative diagnosis of duodenal duplication based on its characteristic endoscopic findings and radiographic presentation].

An 18-year-old woman was admitted to our hospital with pain in the right upper quadrant of the abdomen and fever. Diagnostic imaging studies, namely, upper gastrointestinal roentogenography and endoscopy, were performed, and an oval cystic tumor was detected in the second part of the duodenum. On the basis of the characteristic findings of the imaging studies and blood tests, we established a definitive diagnosis of duodenal duplication complicated with acute pancreatitis, even before surgical exploration. On surgical examination, the main pancreatic duct appeared to communicate internally with the cystic lesion. The histopathological examination of the surgical specimen confirmed the accuracy of the preoperative diagnosis.