Clinical aspects of congenital cystic dilatation of the common bile duct in adults

We reviewed the data for 155 patients with congenital cystic dilatation of the common bile duct (CCDB; Alonso-Lej Type I) treated at our institute in the past 12 years. Our definition of CCDB was segmental enlargement of the common bile duct or enlargement involving the proximal bile duct, visualized on cholangiograms. CCDB was subclassified as infant or adult type cyst, based on the extent of the enlargement and the clinicopathologic findings. The former is typically an enlargement of the common bile duct or an enlargement involving the common hepatic duct, while the latter is an enlargement of the entirety of the extrahepatic ducts or involves the intrahepatic bile ducts. Of the 155 patients, 5 (including 1 child) had infant type cysts and 150 (including 1 child) had adult type cysts; 125 patients had benign CCDB (3 with infant type cyst) and 30 exhibited CCDB biliary malignancy (2 with infant type). Anomalous arrangement of the pancreaticobiliary ductal system (AAPB) and congenital biliary stricture were frequently associated with CCDB and these features played an important role in the presenting symptoms of CCDB: AAPB was detected in 100 of the 155 patients, and stricture in 51. AAPB caused disturbance of the passage of bile from the terminal bile duct to the duodenum and cholestasis in the enlargement, with reciprocal regurgitation of bile into the pancreas and pancreatic juice into the bile duct, and the AAPB appeared to precede obstructive jaundice, acute pancreatitis, or biliary malignancies. Stricture was observed at one to all of six sites in the hepatic hilum. Intrahepatic stones were seen in 30 patients, and intrahepatic bile duct cancer was seen in 8 patients; in all these 8 patients, the cancer was associated with primary intrahepatic stones.