Caroli Disease is a rare inherited disorder characterized by abnormal widening (dilatation) of the ducts that carry bile from the liver (intrahepatic bile ducts). According to the medical literature, there are two forms of Caroli Disease. In most cases, the isolated or simple form Caroli Disease, affected individuals experience recurrent episodes of inflammation of the bile ducts (cholangitis) and unusual accumulation of pus (abscesses) on the liver. A second form of Caroli Disease is associated with abnormal formation of bands of fibrous tissue in the portal area of the liver (congenital hepatic fibrosis). The portal area of the liver is a groove (fissure) where the portal vein and the hepatic artery enter the liver. The portal vein is the blood vessel that carries blood from the stomach, intestine, and spleen to the liver and the hepatic artery is the blood vessel that carries blood from the aorta. This form of Caroli Disease is also often associated with high blood pressure of the portal vein (portal hypertension), polycystic kidney disease, and, in severe cases, liver failure. Caroli Disease is thought to be inherited as either an autosomal dominant or recessive genetic trait.