MUC5AC and pancreatic intraductal papillary-mucinous neoplasm: Similar to intraductal papillary mucinous neoplasm (IPMN) and intraductal papillary neoplasm of the bile duct (IPNB), IOPNs in these sites are characterized by intraductal papillae with delicate fibrovascular cores and frequent mucin hypersecretion.