twenty gallbladders obtained during operations for cholelithiasis , large portions of three common bile ducts obtained during whipple 's procedure for carcinoma of the head of the pancreas , and 155 endoscopic transpapillary biopsy specimens taken during control endoscopy from patients who had had a previous endoscopic sphincterotomy were examined .
C0016976
gallbladders
C0008350
cholelithiasis