Primary hepatolithiasis, recurrent pyogenic cholangitis, and oriental cholangiohepatitis: a tale of 3 countries

Primary hepatolithiasis (HL), recurrent pyogenic cholangitis, and oriental cholangiohepatitis are terms commonly used in Japan, Hong Kong, and Korea respectively, and describing the different aspects of the same disease, with "HL" indicating the pathologic changes, "recurrent pyogenic cholangitis" emphasizing the clinical presentation and suppurative inflammation, and "oriental cholangiohepatitis" highlighting its ethnic preference and mysterious nature. HL is predominantly a disease of the far east and shows great regional differences in the incidence and the type of intrahepatic stones. Pathologically, it is characterized by pigmented calcium bilirubinate stones within dilated intrahepatic bile ducts featuring chronic inflammation, mural fibrosis, and proliferation of peribiliary glands, without extrahepatic biliary obstruction. Episodes of suppurative inflammation cumulate in sclerosing cholangitis in peripheral ducts and parenchymal fibrosis from scarring and collapse. Mass-forming inflammatory pseudotumor and neoplasms-like intraductal papillary neoplasms and cholangiocarcinoma are increasingly recognized complications. Bacterial infection and dietary factors are believed to be important in the formation of pigment stones within intrahepatic bile ducts, whereas parasitic infestation is likely coincidental. With improvement of environmental conditions and westernization of diet, the incidence of pigment stones has decreased. At the same time, cholesterol stones with milder clinical manifestations and pathologic changes are increasingly recognized, and for which stone dissolution therapy can be considered. Understanding the underlying pathology avoids confusion with other diseases more prevalent in the western world, and allows correct selection of the appropriate treatment.