A distinction must first be made between Caroli disease and Caroli syndrome. They have a dilation of the large bile ducts within the liver (intra-hepatic) in common. However, while Caroli disease "only" involves an enlargement of the bile ducts, Caroli syndrome is characterised by liver fibrosis or even cirrhosis with portal hypertension (=high blood pressure in front of the liver). In addition, Caroli syndrome is often associated with cystic kidney disease (autosomal recessive polycystic kidney disease, ARPKD).

Causes of Caroli syndrome

The exact cause of the disease is unclear. Both Caroli disease and Caroli syndrome are caused by a hereditary mutation of the PKHD1 gene. Men and women are affected in approximately 1 in 10,000 births at roughly the same rate. In over 80% of patients, the disease occurs before the age of 30. The gene mutation leads to defective protein formation (fibrocystin), which is important for the composition of bile and for cell division in the liver and kidneys.

Symptoms

Patients are often asymptomatic for a long time. The non-specific complaints of fever, colic, vomiting, weight loss, itching, jaundice, and abdominal pain occur due to bile stasis. Inflammation of the bile ducts (cholangitis) and gallstones are frequent complications. In the late stages, the consequences of liver cirrhosis (e.g. haematemesis, ascites) as well as bile duct tumours can be observed.

Diagnosis

Imaging procedures such as ultrasound, CT and MRI are used for diagnosis. The bile ducts are best visualised by magnetic resonance cholangiography, which shows dilated bile ducts in the case of Caroli disease / Caroli syndrome. Other diseases such as PSC should be excluded.

Treatment

There is no causal therapy available. Antibiotics are used in the case of a bacterial infection of the bile ducts. Interventional or surgical drainage of the bile ducts may be indicated in cases of bile stasis. Ursodeoxycholic acid is also used to dilute the bile. This reduces the likelihood of stone formation and/or inflammation. If only a small part of the liver is diseased, the affected tissue can be removed by surgery. If the entire liver is affected, a liver transplant should also be considered.