The disease was firstly described by Caroli et al. and has autosomal
recessive inheritance
3. Two types of the disease have
been identified, type 1 (Caroli's disease) and type 2 complex
form (Caroli's syndrome) which is associated with congenital
hepatic fibrosis, portal hypertension and cirrosis
6. Caroli's
disease may be localized to one lobe of liver or may be diffuse.
The clinical manifestations of Caroli's syndrome are related
to the biliary abnormalities and portal hypertension7.
There are several clinical presentations depending on the age of
onset and the predominance of hepatic or renal involvement. In
both Caroli's disease and syndrome, the saccular or fusiform
dilatation of bile ducts predisposes to stagnation of bile leading
to the formation of biliary sludge and intraductal lithiasis.
Bacterial cholangitis occurs frequently and may be complicated
by septicemia and hepatic abscess2. Patients with Caroli's
syndrome can present with portal hypertension and its squeal,
such as ascites and esophageal variceal hemorrhage. Other
patients present only with intermittent abdominal pain. Pruritus
is common.
On physical examination, the liver is frequently enlarged.
Patients with renal involvement may also have enlarged kidneys,
which may be palpable. Laboratory studies typically
show an elevation of serum alkaline phosphatase, direct billirubin,
and a leukocytosis with a predominance of neutrophils.
Hepatic synthetic function is well preserved initially, but may
be affected by progressive liver damage due to recurrent
cholangitis and biliary obstruction. Coagulopathy from vitamin
K malabsorption may occur in cholestatic patients8,9.
The diagnosis of Caroli's disease and Caroli's syndrome
is established by imaging studies that demonstrate bile duct
ectasia and irregular, cystic dilation of the large proximal
intrahepatic bile ducts with a normal common bile duct. These
findings can readily be identified with ultrasonography, endoscopic
retrograde cholangiopancreatography, or magnetic
resonance imaging which can also demonstrates the renal
features of cystic disease2,6. A liver biopsy is rarely required
for the diagnosis.
Renal lesions and choledocal cysts are the associated
conditions with Caroli's syndrome. Renal anomalies include
renal tubular ectasia (medullary sponge kidney, cortical cyst),
adult recessive polycystic kidney disease, and rarely autosomal
dominant polycystic kidney disease10,11. Medullary sponge
kidney is described by ectatic and cystic malformations of the
collecting ducts and tubules of one or more papillae of one or
both kidneys. These anatomic abnormalities produce no symptoms.
The morbidity of this disorder is the result from nephrolithiasis
and urinary tract infection, both of which are thought
to be secondary to the anatomic abnormalities12.
There is no curative treatment for Caroli's disease.
Treatment is mainly supportive and should be individualized.
Cholangitis and sepsis are treated with appropriate antibiotics
and biliary stone extraction whenever feasible5. Endoscopic
sphincterotomy and stone extraction can be used to remove
common duct stones. In contrast, the extraction of intrahepatic
stones is far more difficult5. Patients, who have recurrent
attacks of biliary infection, particulary those who also have
complications related to portal hypertension, may need liver
transplantation7. Patients who have developed esophageal
varices should receive prophylaxis with a non-selective beta
blocker13. A selective shunting procedure can provide relief
from portal hypertension if liver function may be well preserved14. Unexplained clinical deterioration or the appearance
of a new biliary stricture should raise a concern that
cholangiocarcinoma has developed15.
Asymptomatic patients with medullary sponge kidney require
no specific therapy except to maintain high fluid intake to
reduce the risk of nephrolithiasis. Infection should be treated
aggressively, and instrumentation of the urinary tract should be
minimized to avoid infection. The prognosis is variable depending
on the severity of liver disease and the presence of
coexisting renal dysfunction. Since the risk of cholangiocarcinoma
is increased up to 7 percent, screening for this complication
important16.
Our patient exhibited clinical and radiologic findings for
Caroli's syndrome with medullary sponge kidney. The absence
of symptom and laboratory finding of hepatic or renal dysfunction
enabled us to keep track progress and observe him until
the development of complication.