Klatskin Tumor: Definition and Clinical Significance
A Klatskin tumor is a cholangiocarcinoma (bile duct cancer) specifically located at the bifurcation of the common hepatic duct where the right and left hepatic ducts join, representing 50-60% of all cholangiocarcinoma cases. 1, 2
Anatomical Location and Classification
Klatskin tumors arise at the hepatic duct bifurcation (perihilar region), distinguishing them from intrahepatic cholangiocarcinomas (within liver parenchyma) and distal extrahepatic tumors (in the common bile duct). 1, 2
Despite their proximity to the liver, these are classified as extrahepatic cholangiocarcinomas, not intrahepatic tumors, though coding errors have historically misclassified them. 1, 2
Perihilar tumors account for 50-60% of all cholangiocarcinomas, while intrahepatic tumors represent 20-25% and distal extrahepatic tumors 20-25%. 1
Bismuth Classification System
The extent of ductal involvement is classified using the Bismuth system, which is critical for surgical planning: 1, 3
- Type I: Tumors below the confluence of left and right hepatic ducts 1, 3
- Type II: Tumors reaching the confluence but not involving hepatic ducts 1, 3
- Type III: Tumors extending into either right or left hepatic duct 3
- Type IV: Tumors involving both hepatic ducts 3
Risk Factors in Older Adults
Primary sclerosing cholangitis (PSC) is the most common predisposing factor in the UK, with a lifetime risk of 5-15% for developing cholangiocarcinoma. 1 This risk is particularly relevant in older adults with inflammatory bowel disease.
Additional risk factors include: 1
- Age over 65 years (65% of patients are in this age group)
- Chronic intraductal gallstones
- Choledochal cysts (5% transformation risk, increasing with age)
- Caroli's disease (7% lifetime risk)
- History of chronic liver disease
Clinical Presentation and Prognosis
Progressive obstructive jaundice is the hallmark presentation, often accompanied by weight loss and pain. 4
The prognosis is poor, with cholangiocarcinoma mortality rates corresponding closely to incidence rates due to late diagnosis. 1
Only 25% of Klatskin tumors are resectable at diagnosis, and only half of these achieve complete resection. 4
Five-year survival rates after complete R0 resection with major hepatectomy range from 20-40%, making surgical resection the only potentially curative treatment. 3
Median survival for unresected patients is less than 6 months, with palliative procedures providing minimal survival benefit. 4
Critical Clinical Pitfall
The absence of early symptoms leads to diagnosis at advanced, incurable stages in most cases. 5 Therefore, elderly patients with abnormal liver function tests, particularly those with PSC or other risk factors, warrant screening for hepatobiliary malignancies even when asymptomatic. 5