Polycystic liver diseases

Polycystic liver diseases are inherited disorders of the biliary epithelium, caused by genetic defects in ciliary- or endoplasmic reticulum-associated proteins. They are characterized by the formation and progressive enlargement of multiple cysts scattered throughout the liver parenchyma. Polycystic liver diseases may be classified into three main different clinical entities, based on the inheritance pattern and involvement of the kidney. Caroli disease and congenital hepatic fibrosis (along with recessive polycystic kidney diseases or ARPKD) are discussed elsewhere in the book. This chapter reviews the autosomal dominant polycystic liver disease with kidney involvement (ADPKD) or limited to the liver (PCLD). Despite extensive cyst substitution of the hepatic parenchyma, liver function is generally well preserved and portal hypertension is rare. The patients are asymptomatic, unless acute and chronic complications (including cyst infections or bleeding) develop. Diagnosis is usually radiological. Medical therapy is not currently available, but interventional radiology and surgical approaches, and, eventually, liver transplantation may be used in selected cases.