Annular pancreas associated with pancreatolithiasis: a case report

We present a case of annular pancreas associated with pancreatolithiasis. A 41 year-old Japanese man with epigastric pain was admitted to the surgical service at Miyazaki Medical College Hospital. Contrast duodenography revealed severe stenosis of the descending duodenum. Cholangiography showed a stenotic segment of the intrapancreatic common bile duct surrounded by calcifications. Computed tomography of the abdomen revealed calcifications in the posterior region of the pancreatic head. Percutaneous cannulation of the pancreatic ductal system, using ultrasonic guidance, demonstrated a slightly dilated pancreatic duct in the body, stenosis of the duct of Wirsung in the pancreatic head, a normal duct of Santorini, and calcifications in the duct of an annular pancreas which communicated with the duct of Wirsung. At surgery, the second portion of the duodenum was completely encircled by the annular pancreas, and a Whipple procedure was performed. Including this patient, 170 adult cases of annular pancreas have been reported in Japan since 1922. Surgery was performed on 122 patients; 106 of these procedures were well documented. A Whipple procedure was performed on 16 patients, including the present case. Nine of these 16 patients had associated malignant disease, while the others had benign pancreatic disease. This is the fifth reported case of pancreatolithiasis associated with an annular pancreas in Japan. This case emphasizes that an annular pancreas may predispose to localized chronic pancreatitis and pancreatolithiasis.