Caroli’s Disease

Adrish Sarkar, Razia Rehmani, MD

Key Points:

  • Caroli disease and Caroli syndrome are both congenital disorders that involve nonobstructive saccular or fusiform segmental dilatation of the intrahepatic bile ducts.
  • Caroli syndrome is distinguished from Caroli disease due to accompanying hepatic fibrosis.
  • Caroli disease is a rare pathology with an estimated incidence of 1/1,000,000. Involvement of the left lobe of the liver is most typical.
  • There is an association with fibrocystic renal pathologies.
  • Clinically, patients are prone to biliary lithiasis, sludge formation, cholangitis, portal hypertension, and progressive hepatic dysfunction.
  • Imaging modalities are crucial for diagnosis. The “central dot sign” may be seen on MRI or CT scans. ERCP has the greatest sensitivity.
  • Surgery can be curative for focal involvement while diffuse presentations are managed supportively.

 

Discussion.

Caroli disease is a congenital disorder that was first described by Jaques Caroli in 1958 as multifocal, nonobstructive saccular or fusiform segmental dilatation of the intrahepatic bile ducts.(1) In contrast to Caroli syndrome which involves both bile duct dilation and hepatic fibrosis, Caroli disease is characterized by bile duct ectasia without additional hepatic abnormalities. Both conditions have an autosomal recessive inheritance and are associated with autosomal recessive polycystic kidney disease. Caroli disease is rare with an estimated incidence of 1/1,000,000. The prevalence is equal between men and women and most cases (more than 80%) present before age 30.(2)

The pathogenesis of Caroli disease, while incompletely understood, is tied to mutations on the PKHD1 gene which codes for fibrocystin. The resulting derangement of embryologic remodeling of bile ducts and destructive inflammatory processes are thought to underlie both Caroli disease and syndrome.(3) The dilated segments are continuous with the rest of the biliary tract and may be limited to a single lobe of the liver (most commonly the left lobe).

Clinically, the dilation of intrahepatic bile ducts predisposes patients to biliary sludge and stone formation. There is an additional risk for cholangitis, secondary biliary cirrhosis, abscess formation, and sepsis. Patients may present with abdominal pain, pruritus, or signs of portal hypertension. Hepatosplenomegaly may be appreciated on a physical exam. The extent of hepatic dysfunction will vary and can be worse due to concomitant fibrosis in those with Caroli syndrome.

Various imaging modalities can be used to identify the dilated intrahepatic bile ducts with a normal common bile duct. The central dot sign, a small foci of strong contrast enhancement within the dilated intrahepatic ducts, can be detected using CT or MRI scans.(4) Concomitant fibrocystic pathologies of the kidneys may also be seen. ERCP provides the greatest sensitivity for diagnosis of Caroli disease.(2) Imaging can help distinguish Caroli disease from primary sclerosing cholangitis in which ductal dilations are rarely saccular and from polycystic liver disease in which hepatic cysts rarely communicate with the bile ducts.

Treatment for Caroli disease is largely supportive and dependent on both the extent of disease involvement and associated pathological findings. Diseased localized to a single lobe of the liver can be cured by hemi-hepatectomy.(2) Associated cholangitis may require antibiotics and biliary stone extraction while a shunting procedure may be needed for portal hypertension. Prognosis will depend on the severity of liver dysfunction and patients may be prone to recurrent infections resulting from lithiasis. Co-existing renal pathology is an additional important consideration for prognosis.

 

References

  1. Miller WJ, Sechtin AG, Campbell WL, Pieters PC. Imaging findings in Caroli’s disease. AJR Am J Roentgenol. 1995;165(2):333-7.
  2. Yonem O, Bayraktar Y. Clinical characteristics of Caroli’s disease. World J Gastroenterol. 2007;13(13):1930-3.
  3. Ward CJ, Hogan MC, Rossetti S, Walker D, Sneddon T, Wang X, et al. The gene mutated in autosomal recessive polycystic kidney disease encodes a large, receptor-like protein. Nat Genet. 2002;30(3):259-69.
  4. Lefere M, Thijs M, De Hertogh G, Verslype C, Laleman W, Vanbeckevoort D, et al. Caroli disease: review of eight cases with emphasis on magnetic resonance imaging features. Eur J Gastroenterol Hepatol. 2011;23(7):578-85.
  5. B I Choi, K M Yeon, S H Kim, M C Han. Caroli disease: central dot sign in CT. (1990) Radiology. 174 (1): 161-3.
  6. R. Yashmita, Kyoto/JP. ECR 2015 / C-0722. Imaging features of ductal plate malformations: A case based review

Authors


Adrish Sarkar


Medical Student
Cuny School of Medicine
Bronx, NY


Razia Rehmani, MD


Chief of Neuroradiology & Musculoskeletal Imaging
Diagnostic Radiology
St Barnabas Health System
Bronx, New York