A congenital disorder of the intrahepatic bile ducts
characterized by intrahepatic dilatation of the biliary tree, which may
result in cholangitis, cholelithiasis, sepsis, hepatic failure, and portal
Congenital Dilatation of Intrahepatic Bile Ducts;
Communicating Cavernous Ectasia of Intrahepatic Bile Ducts; Choledochal
Cysts Type V (Todani classification).
The exact incidence is not known but is considered to be
very low (probably fewer than 200 cases described in the literature). Caroli syndrome occurs more frequently than Caroli disease (see
Clinical Aspects for differentiation). Both forms are more common in females.
Not precisely known. Autosomal recessive has
been suggested for both Caroli disease and Caroli syndrome.
In Caroli disease, polycystic segmentation of the
larger intrahepatic bile ducts (segmental, left and right) occurs, whereas
in Caroli syndrome the ductal abnormalities are more widespread. Both forms
are characterized by fibrosis of the portal tracts. Both Caroli disease and
Caroli syndrome are thought to originate from a pathologic development in
the formation of the ductal plate. The ductal plate originates from
hepatocytes surrounding the intrahepatic portal vein branches. Further
differentiation during fetal life results in the formation of small tubules,
which coalesce to form the intrahepatic biliary tree. Failure of the ductal
plate to differentiate are summarized as ductal plate malformations. The
anomalous structure of the intrahepatic bile ducts leads to saccular or
fusiform dilatation and ectasia with biliary stasis, cholelithiasis,
cholangitis with intrahepatic abscesses, and recurrent sepsis.
Diagnosis of exclusion. Fetal ultrasound examination of liver
and kidneys during pregnancy has resulted in prenatal diagnosis of Caroli
disease/syndrome. However, further radiologic investigations (computed
tomography scanning, magnetic resonance imaging, cholangiography),
endoscopic retrograde cholangiopancreatography, and liver biopsy may be
required to confirm the diagnosis. Approximately half of the patients also have
extrahepatic fusiform enlargement of the common hepatic and common bile duct.
The findings in Caroli disease are limited to
ectasia or segmental dilatation of the larger intrahepatic ducts. In Caroli
syndrome, which is more common than Caroli disease, the pathologic findings
include smaller bile ducts and congenital hepatic fibrosis. Caroli disease
frequently presents with complications as a result of cholangitis (fever,
right upper quadrant pain). The first presentation of Caroli syndrome may
result from complications of portal hypertension, most often upper
gastrointestinal bleeding. Liver cirrhosis has been described. Overwhelming
sepsis with death is not a rare complication for these patients. On
examination, jaundice hepatomegaly, splenomegaly, and renal masses associated with
renal disease may be found. Although presentation is most frequently in
adulthood, childhood and neonatal cases have been described. Patients are at
risk for progressive hepatic failure. Caroli disease/syndrome can coexist
with medullary sponge kidney, medullary cystic kidney disease, and autosomal
recessive polycystic kidney disease (renal cysts, interstitial fibrosis,
potential for renal insufficiency). Occasionally, the disorder is limited to
one liver lobe (commonly the left) or segment only, and hepatic lobectomy has been used to treat
these cases. Liver transplantation has been used for ...