Which type of carcinoma is known to arise at the union of the right and left hepatic ducts?

The carcinoma that arises at the union of the right and left hepatic ducts is known as a Klatskin tumor, which is a type of cholangiocarcinoma. Specifically, Klatskin tumors develop at the hepatic duct bifurcation, where the right and left hepatic ducts converge before they enter the common hepatic duct. This region is particularly susceptible to the development of tumors because of the unique anatomy and flow of bile from both lobes of the liver.

Klatskin tumors are significant not only due to their location but also because they can obstruct bile flow, leading to significant clinical consequences such as jaundice and cholangitis. The distinction is critical as this anatomical site requires specific management strategies and has different prognostic implications compared to other types of carcinomas, such as hepatocellular carcinoma or pancreatic adenocarcinoma.

While cholangiocarcinoma broadly refers to cancers that originate in the bile ducts, Klatskin tumors specifically denote those that occur at the junction of the hepatic ducts, making the identification of this condition essential in clinical practice and imaging evaluations. This specificity underscores the importance of recognizing anatomical details in conjunction with pathological types of carcinomas in the abdomen.