Hereditary hemorrhagic telangiectasia (liver manifestations)

Hepatic manifestations of Hereditary hemorrhagic telangiectasia (HHT), which is also known as Osler-Weber-Rendu syndrome, are typically seen on imaging as multiple telangiectasias and arteriovenous malformations (i.e. arteriovenous and portovenous shunts). These multiple shunts lead to a hyperdynamic circulation and therefore, possible high-output cardiac failure.

For a general discussion of the underlying condition, please refer to the article on hereditary hemorrhagic telangiectasia (HHT). 

Epidemiology

Although it has been historically estimated in about 30% ^4,5, new reports of the hepatic involvement in hereditary hemorrhagic telangiectasia indicate a higher incidence, on the order of ~80% ³. 

Clinical presentation

Slightly over half of the patients are asymptomatic. Symptoms tend to develop when there are extensive vascular shunts causing a hyperdynamic circulation; these may include symptoms due to secondary ⁴:

• high-output cardiac failure
• portal hypertension
• portosystemic encephalopathy 
• cirrhosis

Radiographic features

Liver involvement in hereditary hemorrhagic telangiectasia is best assessed with multiphase CT images. 

• telangiectasis
  • most commonly found hepatic lesion ³
  • sub centimeter hypervascular focal lesions resembling an asterisk 
  • MIP reformats from CT arterial phase images are extremely helpful in demonstrating them  
  • large confluent vascular masses: term described to refer to multiple coalescing telangiectases that form vascular mass-like lesions ³
• hepatic perfusion abnormalities
  • heterogeneous attenuation enhancement pattern of the liver parenchyma, which tends to be more diffuse (nonfocal) and ill-defined ³
  • transient hepatic attenuation differences (THAD) may be present
• arteriovenous shunts: communication between the hepatic artery and hepatic vein
  • hepatic vein filling with contrast on arterial phase
  • enlarged hepatic artery and hepatic veins due to high-output shunting
  • associated with telangiectasis ³
• arterioportal shunts: communication between the hepatic artery and portal vein 
  • portal vein opacification on arterial phase 
  • associated with THAD
• portovenous shunts: communication between the portal and hepatic veins
  • rarely seen in HHT ³
  • dilated portal vein branch bridging to a hepatic vein
  • best seen on portal venous phase 
  • occult at angiography ³