However, they may be useful in conjunction with imaging methods in supporting a suspected diagnosis of cholangiocarcinoma. Abdominal imaging
Ultrasound of the liver and biliary tree is often used as the initial imaging modality in people with suspected obstructive jaundice. Ultrasound can identify obstruction and ductal dilatation and, in some cases, may be sufficient to diagnose cholangiocarcinoma. Computed tomography (CT) scanning may also play an important role in the diagnosis of cholangiocarcinoma. Imaging of the biliary tree
While abdominal imaging can be useful in the diagnosis of cholangiocarcinoma, direct imaging of the bile ducts is often necessary. Endoscopic retrograde cholangiopancreatography (ERCP), an endoscopic procedure performed by a gastroenterologist or specially trained surgeon, has been widely used for this purpose. Although ERCP is an invasive procedure with attendant risks, its advantages include the ability to obtain biopsies and to place stents or perform other interventions to relieve biliary obstruction. Endoscopic ultrasound can also be performed at the time of ERCP and may increase the accuracy of the biopsy and yield information on lymph node invasion and operability. As an alternative to ERCP, percutaneous transhepatic cholangiography (PTC) may be utilized. Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive alternative to ERCP. Some authors have suggested that MRCP should supplant ERCP in the diagnosis of biliary cancers, as it may more accurately define the tumor and avoids the risks of ERCP. Surgery
Surgical exploration may be necessary to obtain a suitable biopsy and to accurately stage a person with cholangiocarcinoma.
The prevalence of cholangiocarcinoma in people with primary sclerosing cholangitis may be as high as 30%, based on autopsy studies.Multiple studies have documented a steady increase in the incidence of intrahepatic cholangiocarcinoma; increases have been seen in North America, Europe, Asia, and Australia. The reasons for the increasing occurrence of cholangiocarcinoma are unclear; improved diagnostic methods may be partially responsible, but the prevalence of potential risk factors for cholangiocarcinoma, such as HIV infection, has also been increasing during this time frame. References
External links

American Cancer Society Detailed Guide to Bile Duct Cancer. Patient information on extrahepatic bile duct tumors, from the National Cancer Institute. Cancer.Net: Bile Duct Cancer
Cholangiocarcinoma Foundation
World Cholangiocarcinoma Day