PED17

 Caroli disease and caroli syndrome are congenital disorders to the intarhepatic bile ducts. They are both characterized by dilatation of the intrahepatic biliary tree.  The term Caroli disease is limited to ectasia or segmental dilatation of the large intrahepatic ducts. This form is less common than caroli syndrome, in which malformations of small bile ducts and congenital hepatic fibrosis are also present. This process can be either diffuse or segmental and may be limited to one lobe of the liver.

 Data on five patients with the diagnosis of Caroli’s syndrome were entered into the archives of our institution from Junuary 1990 to December  It was composed of three girls and two boys. CasesexAge of diagnosis Cosanguineo us marriage 1F3 yearsNo 2F9 monthsFirst degree 3F8 yearsFirst degree 4M17 monthsNo 5M2 yearsFirst degree

 In our cases, childs were diagnosed at a relatively young age  The physical examination findings of hard hepatomegaly and firm splenomegaly made us suspect the diagnosis which was then confirmed by ultrasound abdomen or liver biopsy.  Patients with caroli syndrome may have recurrent episodes of cholangitis and are also at risk for associated bacteremia and sepsis (4M/5).  They may also have complications of portal hypertension as is observed in congenital hepatic fibrosis ( hematemesis or melena secondary to bleedingvarices and ascites 3M/5 )  Associated cystic dilatation of kidneys was seen in 4 cases of our 5 patients ( renal tubular ectasia, medullary sponge kidney, cortical cyst, recessive polycystic kidney disease or rarely autosomal dominant polycystic kidney disease was discrebed ). These patients are usually asymptomatic but may develop renal stone disease and infections.  It is also associated with a risk of cholangiocarcinoma at a rate of 100 times that of the general population.

 Ultrasonography is the initial investigation of choice ; the pure form shows diverticulum like sacculi of intrahepatic biliary tree, more pronounced towards the center and can be segmental or generalized. It consists of portal vein radicles surrounded by the dilated bile ducts.  Kidney may be normal or of variable echogenicity.

Hepatomegaly with bile ducts

Polycystic kidney

Polycystic kidney disease associated to Caroli’s syndrome

 Scan is an invaluable adjunct that complements ultrasound. It can identify cholangiocarcinoma and hepatic masses not identified by ultrasound.  In the diagnosis of Caroli syndrome, the liver biopsy is not conclusive in all cases ; therefore the rapports of radiology above all the ultrasound scan.  The diagnosis is more difficult to establish in the case of fusiform dilatations of the biliary tracts and endoscopic retrograde cholangiopancreatography is the gold standard in this situation. In our cases, this investigation was not required.

Multiple hypodense rounded areas Dilated intrahepatic bile ducts

Saccular bile duct dilatation in caroli disease

Contrast-enhanced CT scan shows marked intrahepatic ductal dilatation Involving entire liver. Enhancing central fibrovascular buddles are identified in many of dilated ducts ( central dot sign ) Enlarged spleen is partially visible

Contrast –enhanced CT scan shows intra and extrahepatic bile duct dilatation. Many intrahepatic ducts contain peripherally enhancing fibrovascular bundles.

Varices in caroli’s syndrome associated to ARPKD Axial contrast-enhanced CT scan shows enlarged and tortuous splenic veins, indicating portal hypertension

MRI : Caroli disease and autosomal polycystic kidney disease ( T2 )

 Ultrasonography is widely available and is often used first in the diagnosis.  CT imaging is excellent for screening patients.  MRI can aid in the diagnosis. Also magnetic resonance cholangiopancreatography can be performed, and images show ductal anatomy well.  ERCP can be also performed in patients with Caroli disease.

 Congenital fibrosis is a histopathological diagnosis  Histopathological intrahepatic bile duct ectasia and proliferation are associated with severe periportal fibrosis and confirm the congenital hepatic fibrosis componenet of Caroli’s syndrome.  Periductal fibrosis and stones were visible macroscopically in 3 patients.

Portal bile duct surrounded by chronic inflammation Fibrous portal expansion with bile ductules along septa is consistent with congenital hepatic fibrosis

 The cause appears to be genetic. The simple form in an autosomal dominant trait while the complex form is an autosomal recessive trait.  Females are more prone to caroli disease than males.  Family history may include kidney and liver disease due to the link between caroli disease and ARPKD ( autosomal recessive polycystic kidney disease ).

 PKHD 1, the gene linked to ARPKD, has been found mutated in patients with Caroli syndrome.  The genetic basis for the difference between Caroli disease and Caroli’s syndrome has not be defined. Location of the PKHD 1 gene on chromosome 6

 The treatment depends on clinical features and the location of the biliary abnormality.  Antibiotics are used to treat the inflammation of the bile duct and ursoeoxycholic acid for hepatolithiasis (Ursodiol ).  In diffuse cases of Caroli disease, treatment options include conservative or endoscopic therapy, internal biliary bypass procedures and liver transplantation in carefully selected cases.

 Caroli’s syndrome is a rare congenital anomaly, it should be included in differential diagnosis in children presenting with abdominal pain and hepatomegaly.  Caroli’s syndrome and its complications have overlapping radiologic appearances that reflect the underlying pathology of fibrosis, ductal dilatation, cholangitis, stone formation, malignancy and renal cysts when they are associated.  In a genetic level, unbalanced translocation between the chromosome 3 and 8 seems to be responsible. This explains the familial clustering and its association with polycystic kidney disease. The natural history of caroli’s disease diagnosed antenatally is unclear.

Thank you Rdte Inès Selmi