pancreatic duct blockagepancreatic duct carcinomaenlarged pancreatic duct causesmalignant neoplasm of pancreatic ductcholangiocarcinoma pancreatic cancerpancreatic cholangiocarcinomapancreatic ductaldilated biliary ductbreast cancer in ductliver duct cancerbiliary duct blockage symptomsbiliary duct carcinoma