Intramural pseudocyst of the duodenum caused by pancreatic head cancer: report of a case.

An intramural pseudocyst in the alimentary tract develops as a rare complication of acute pancreatitis or trauma. A 60-year-old woman with pancreatic head cancer underwent preoperative radiological examinations, which revealed a 45-mm cystic mass around the second portion of the duodenum. Endoscopic ultrasonography confirmed a cystic lesion in the submucosal layer of the duodenum and fine needle aspiration cytology of the cystic contents suggested adenocarcinoma. The cystic fluid was amylase-rich, at 17040 U/l. We performed pancreaticoduodenectomy for the pancreatic head cancer. Pancreatography of the resected specimen showed a communication between the main pancreatic duct and the cystic lesion. The cut surface of the resected specimen revealed a cystic lesion, which surrounded the duodenum. Pathologically, the cystic lesion was diagnosed as a pseudocyst, located between the dissociated smooth muscle layers of the duodenum.