Recurrent chemical pancreatitis complicating choledochal cystic disease

Abstract

A seventeen year old lady presented with a twelve year history of self-limiting attacks of severe epigastric pain, associated with occasional fever, normal total white cell count (WCC), normal or mildly elevated serum alanine transaminase (ALT) (13-200iu/l) and variable hyperamylasaemia (127-460iu/l). At age 5 years, abdominal ultrasonography had shown non-cystic dilatation of the intrahepatic and extrahepatic biliary system without choledocholithiasis. Despite endoscopic sphincterotomy of a normal ampulla with extraction of bile duct stones at age eleven years, followed by laparoscopic resection of a dilated gall bladder, the attacks increased in frequency. Subsequent endoscopic retrograde cholangio pancreatography (ERCP) confirmed biliary dilatation in the absence of stones but the pancreatic duct was poorly outlined. At age 15 years a magnetic resonance cholangiopancreatogram (MRCP) showed generalised dilatation of the extrahepatic biliary tree involving the common hepatic duct and the porta hepatis with a large elongated choledochal cyst arising out of the lateral wall of the common bile duct (CBD). These findings are best seen in a coronal view (Figure 1) which also shows a normal pancreatic duct joining the CBD about 15mm proximal to the level of the ampulla. This suggests a long common pancreatobiliary channel running through the pancreatic head before entering the duodenal wall (Figure 2). The patient underwent excision of the dilated biliary tract above the anomalous pancreaticobiliary junction with Roux en Y hepatico-jejunostomy. A small cystic lesion in the jejunal wall was also excised. Histology of the resected specimens showed mildly inflamed choledochal malformations with no dysplasia. Postoperative recovery was uneventful. Follow up MRCP surveillance for neoplasia at six month intervals showed a patent hepatico-jejunostomy and an unchanging filling defect in the intapancreatic bile duct stump remnant with anterior meniscal indentation typical of a trapped air bubble (Figure 3).