Introduction

Fibrocystic liver disease refers to a heterogeneous group of disorders that share some pathophysiologic and clinical features but have important differences. Cystic dilatation of intrahepatic bile duct structures and variable degrees of portal fibrosis are the hallmarks of fibrocystic liver disease. In most instances, there are morphologic abnormalities in the kidneys and pancreas that parallel those of the liver. For this reason, and to appreciate more thoroughly the shared pathogenesis and implications for organogenesis, fibrocystic liver disease and corresponding renal counterparts are discussed together.

It has been recognized for centuries that hepatic and renal cysts are seen in the same individuals [1], although it has not always been accepted that they are manifestations of the same diseases. The older literature contains confusing descriptive classifications of fibrocystic diseases, with imprecise and overlapping definitions. Even now, attempts at describing clinical and radiographic features, prognosis, natural history, and treatment are somewhat hampered by reliance on these descriptive reports. However, much of the molecular basis for these disorders has been elucidated, and clinical diagnoses are being modified using more exact genetic criteria. The current consensus is that genetic determinants of differentiation and development of renal tubules and biliary structures result in a broad spectrum of congenital abnormalities grouped under the heading of fibrocystic liver and kidney disease.

Fibrocystic liver disease refers to a heterogeneous group of disorders that share some pathophysiologic and clinical features but have important differences. Cystic dilatation of intrahepatic bile duct structures and variable degrees of portal fibrosis are the hallmarks of fibrocystic liver disease. In most instances, there are morphologic abnormalities in the kidneys and pancreas that parallel those of the liver. For this reason, and to appreciate more thoroughly the shared pathogenesis and implications for organogenesis, fibrocystic liver disease and corresponding renal counterparts are discussed together.

It has been recognized for centuries that hepatic and renal cysts are seen in the same individuals [1], although it has not always been accepted that they are manifestations of the same diseases [2]. The older literature contains confusing descriptive classifications of fibrocystic diseases, with imprecise and overlapping definitions. Even now, attempts at describing clinical and radiographic features, prognosis, natural history, and treatment are somewhat hampered by reliance on these descriptive reports. However, much of the molecular basis for these disorders has been elucidated, and clinical diagnoses are being modified using more exact genetic criteria. The current consensus is that genetic determinants of differentiation and development of renal tubules and biliary structures result in a broad spectrum of congenital abnormalities grouped under the heading of fibrocystic liver and kidney disease [3].

Embryologic development of the liver has been discussed elsewhere (see Chapter 1) and will not be fully reviewed here.