Fairly specific and important duodenoscopic findings for diagnosing mucinous ductal ectasia (MDE) of pancreas include a prominant ampulla, patulous ampullary orifice and extrusion of mucin through the ampulla. However, we have experienced two cases of mucinous ductal ectasia without these pathognomonic appearance of ampulla. Initially, two cases were admitted for evaluation of pancreatic multicystic lesions, and MDE was incidentally found. Their pancreatographic findings showed normal main duct and cystic dilatation confined to the branch ducts. On gross findings of surgical specimens, a duct dilatation with gelatinous mucin was localized at the uncinate process of the pancreas. Microscopically, the ductal epithelia containing mucin were lined with well-differentiated tall columnar cells showing focal hyperplastic change. We report these unusual cases of MDE with review of the literatures. (Korean J Gastrointest Endosc 19: 843∼847, 1999)