Intrahepatic cystic biliary dilatation constitutes a significant prognostic factor in patients with primary sclerosing cholangitis.

• Cystic dilatation of the intrahepatic biliary ducts affects young patients with primary sclerosing cholangitis and is characterized by a markedly variable radiological evolution. • Biliary wall inflammation, found in explanted livers, could be a key feature in the pathogenesis of cystic dilatation. • Cystic dilatation of the intrahepatic biliary ducts is characterized by an unfavorable course and constitutes a significant prognostic factor of primary sclerosing cholangitis.