• Two subtypes of Caroli’s disease have been described:

• Simple type

• As classically described, without cirrhosis or portal hypertension
• 60-80% associated with medullary sponge kidney

:* Periportal fibrosis type

• Also associated with:

• Congenital hepatic fibrosis – bland portal fibrosis, hyperproliferation of interlobular bile ducts within the portal areas, with variable shapes and size of bile ducts, and preservation of normal lobular architecture.
• Cirrhosis
• Portal hypertension (HTN)
• Esophageal varices
• Renal cystic lesions also often occur

• Hepatic function is preserved in most, but many patients have recurrent cholangitis, liver abscesses and portal hypertension.

• The cysts are nonobstructive saccular or fusiform dilatations of the intrahepatic ducts.
• The disease may be unilobed or bilobed. Unilobed disease is most commonly localized to the left lobe of the liver.
• Some reviews have reported that pure Caroli’s disease is not that common, and more patients actually have Type IVA disease, with both intra- and extra-hepatic cysts.
• Intrahepatic biliary cystic disease should be differentiated from polycystic liver disease, an autosomal dominant disorder characterized by cystic collections of serous fluid not in communication with the biliary tree.
• The incidence of malignant transformation in intrahepatic cysts is ~7% in Caroli’s disease.