Introduction

There is a wide spectrum of etiologically obscure inflammatory disorders of the biliary tract, including the obstructive cholangiopathies that occur in infancy (biliary atresia and related entities), primary biliary cirrhosis, which is noted in adults, and primary sclerosing cholangitis (PSC), which may affect patients of all age groups, particularly those with chronic inflammatory bowel disease (IBD). These hepatobiliary disorders differ markedly in clinical expression but display substantial overlap in morphologic features, suggesting that their pathogenesis may be shared. Because the intra- and extrahepatic biliary tree may be assumed to possess a limited repertoire of reactions to injury caused by various inflammatory mechanisms, the association of PSC and IBD may provide insight into other forms of “cholangitis.” The frequency of this association also presents an opportunity to trace the evolution of PSC. This chapter focuses on idiopathic forms of sclerosing cholangitis in children, the PSC–IBD complex, and related disorders.

Definition

Sclerosing cholangitis is a chronic hepatobiliary disorder characterized by inflammation of the intra- and/or extrahepatic ducts, leading to focal dilatation, narrowing, or obliteration accompanied by local periductular fibrosis. Progressive, obliterative fibrosis usually leads to biliary cirrhosis and end-stage liver disease. The structural abnormalities of larger bile ducts are best appreciated by cholangiography, which in most cases is essential in establishing the diagnosis. However, careful delineation of the histology of the hepatic parenchyma and smaller intrahepatic ducts may also suggest the diagnosis.