A duodenal duplication cyst communicated with an accessory pancreatic duct.

We treated a 49 year-old woman with acute pancreatitis, in whom there was an accessory pancreatic duct which opened into a duodenal duplication cyst. Epigastric pain associated with vomiting and fever were present. Laboratory data showed leukocytosis and hyperamylasemia. An upper G-I series revealed a stricture at the pyloric region. At operation a spherical mass of 6 cm in diameter was present between the greater curvature of the pyloric region and the head of the pancreas. The cyst was removed by hemigastrectomy and partial resection of the head of the pancreas. The accessory pancreatic duct opened into the cyst. Taking particular note of the communication with the pancreatic duct, this cyst was diagnosed as one of duodenal duplication. A duodenal duplication cyst communicating with the accessory pancreatic duct is rare and is dissimilar to any of the 20 cases of duodenal duplication reported in Japan since 1960.