CAROLIS DISEASE CLINICAL RADIOLOGY

Carolis disease (congenital intrahepatic biliary dilatation)
This is a rare, congenital condition in which the bile ducts are irregularly dilated with diverticulalike projections. These diverticula may become infected and may separate off from the biliary duct, forming choledochal cysts. In most cases, the entire hepatobiliary system is affected to some degree. Sufferers may present in early childhood, with symptoms of portal hypertension, or may remain well until adulthood, presenting with cholangitis. It is generally thought to be an autosomal recessive inherited condition and the prognosis is poor. Medical control of associated portal hypertension with varices can improve the quality of life.

In a few cases, the disease is confined to one or two segments of the liver, in which case a cure can be effected with hepatic resection. The extrahepatic biliary tree is often unaffected. The ultrasound appearances are usually of widespread intrahepatic duct dilatation, with both saccular and fusiform biliary ectasia. Because it is also associated with biliary stone formation, the diagnosis is often not clear. The dilatation is also associated with cholangitis and signs of infection may be present in the form of debris within the ducts. Sometimes, frank choledocal cysts can be located. Advanced disease is associated with portal hypertension and, in some cases, cholangiocarcinoma.

Parasites
Parasitic organisms, such as the Ascaris worm and liver fluke, are extremely rare in the UK. However, they are a common cause of biliary colic in Africa, the Far East and South America. The hyperechoic linear structures in the gallbladder lumen should raise the sonographers suspicion in patients native to, or who have visited these countries. Impacted worms in the biliary ducts may mimic other ductal masses. They are a rare cause of obstructive biliary dilatation. Patients may present with acute cholangitis or abdominal pain and vomiting. Endoscopic management is frequently highly effective.