Monarch Disease Ontology id MONDO_0021321 (malignant tumor of extrahepatic bile duct) is a cancer that involves the extrahepatic bile duct. Also known as: cancer of extrahepatic bile duct, malignant extrahepatic bile duct neoplasm, malignant extrahepatic bile duct tumor, malignant extrahepatic bile duct tumour, malignant neoplasm of extrahepatic bile duct, malignant neoplasm of the extrahepatic bile duct, malignant tumor of the extrahepatic bile duct, malignant tumour of the extrahepatic bile duct.