An epithelial, usually multiloculated neoplasm arising from the intrahepatic or extrahepatic bile ducts. It occurs predominantly in females. Signs and symptoms include abdominal mass, abdominal pain, and jaundice. Morphologically, the cystic spaces are lined by columnar epithelium and contain mucinous or serous fluid. The disease is bile duct cystadenoma (Monarch Disease Ontology entry MONDO_0003420). Also known as: bile duct cystadenoma (morphologic abnormality), bile duct mucinous cystic neoplasm, cystadenoma of bile duct, cystadenoma of the bile duct.