Choledochocele associated with superficial spreading cancer with cholesterolosis of the bile duct.

A 74-year-old woman, who had suffered from acute cholangitis, was referred to our department for further evaluation of the biliary tree. A diagnosis of choledochocele was made by endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography. A small flat elevation with cholesterolosis was observed in the lower bile duct, and circumferential wall thickening was apparent in some parts of the upper and middle bile duct by intraductal ultrasonography and peroral cholangioscopy. With the diagnosis of choledochocele associated with superficial spreading cancer and cholesterolosis of the bile duct, pylorus-preserving pancreaticoduodenectomy was carried out. Microscopically, the tumor had spread extensively from the lower to the upper bile duct. Its invasion was limited to the mucosa for the most part, with microinvasion of the subserosa in the upper bile duct. In the lower bile duct, foamy cells were located beneath the neoplastic epithelium of the elevation. The number of cases of choledochocele associated with biliary cancer is becoming higher than previously reported. This anomaly may play some role in the development of biliary malignancy. Histological examination seems to be mandatory before making a diagnosis of cholesterolosis of the bile duct, since this condition may occasionally accompany cancer.