the necessity for making a distinction among tumors arising in the ampulla of vater , the intrapancreatic portion of the common bile duct , and the duodenum surrounding the papilla of vater and carcinomas arising in the head of the pancreas is the most important factor in the approach to periampullary malignant tumors .
C0013303
duodenum
C1335377
periampullary malignant tumors