not specified as primary or sec C23 Malignant neoplasm of gallbladder C240 Malignant neoplasm of extrahepatic bile duct C241 Malignant neoplasm of ampulla of Vater C249 Malignant neoplasm of biliary tract, unspecified C250 Malignant neoplasm of head of pancreas C251 Malignant neoplasm of body of panc...