摘要
Annular pancreas is a congenital anomaly which .consists of a ring of pancreatic tissue partially or completely encircling the descending portion of the duodenum. It was first described by Tiedemann in 1818 and named ＂annular pancreas＂ by Ecker in 1862. The first surgical treatment of obstructive annular pancreas was performed on a neonate by Vidal et al in 1905. In the past, the diagnosis of this anomaly was usually made by surgery or autopsy. With the widespread use of endoscopic retrograde cholangiopancreatography （ERCP） and magnetic resonance cholangiopancreatography （MRCP）, more cases are diagnosed preoperatively. We reported two adult cases of annular pancreas with unsuccessful ERCP because of obstruction above the Vater＇s papilla and undefinitive diagnostic MRCP, and discussed its clinical characteristics of this anomaly.
Annular pancreas is a congenital anomaly which .consists of a ring of pancreatic tissue partially or completely encircling the descending portion of the duodenum. It was first described by Tiedemann in 1818 and named ＂annular pancreas＂ by Ecker in 1862. The first surgical treatment of obstructive annular pancreas was performed on a neonate by Vidal et al in 1905. In the past, the diagnosis of this anomaly was usually made by surgery or autopsy. With the widespread use of endoscopic retrograde cholangiopancreatography （ERCP） and magnetic resonance cholangiopancreatography （MRCP）, more cases are diagnosed preoperatively. We reported two adult cases of annular pancreas with unsuccessful ERCP because of obstruction above the Vater＇s papilla and undefinitive diagnostic MRCP, and discussed its clinical characteristics of this anomaly.
