Also known as a cholangiocarcinoma. It originates from the epithelium (inner lining) of the bile duct, which is a tube that carries bile from the liver to the duodenum. The gallbladder is portion of the bile duct. A cancer of the bile duct will typically obstruct the bile duct, resulting in jaundice. Other non-malignant diseases can cause jaundice as well, and must be distinguished. These include liver dysfunction, gallstones, and problems with the pancreas. Bile duct cancers can be difficult to diagnose, and frequently the decision to operate depends on the whole clinical spectrum, rather than a specific tissue diagnosis.  Pre-op evaluation includes ERCP, CT scan, possibly PTC (percutaneous transhepatic cholangiopancreatography).  Unfortunately, adequate tissue prior to surgery for diagnosis may be obtained in only 50 to 75% of patients.