GI Radiology > Liver > Masses > Hepatocellular Carcinoma


Hepatic Masses

Hepatocellular Carcinoma
  1. Pathogenesis:
  • Incidence of HCC has doubled during the past 20 years.
     
  • Typically, occurs in an abnormal liver. Rare de novo development of HCC.
     
  • Risk factors include:
  1. Cirrhosis of any cause. 80 % of HCC arise in cirrhosis. Cirrhosis from hepatitis B and/or C has the highest risk for HCC.
  2. Hemochromatosis
  3. Steroid use
  4. Hepatitis B or C infection
  5. Liver fluke infestation (especially in southeast asia)
  • A typical progression: Cirrhosis--Regenerating nodules--Dysplasia--HCC.
     
  • HCC can be single (50%), multiple (40%), or diffuse (10%). Often accompanied by hemorrhage and necrosis.
     
  • HCC tends to invade the portal and hepatic veins and may cause thrombosis.
  • HCC can also calcify.  Three other causes of a calcified liver mass include: (1) granulomatous disease, (2) Metastasis from the colon or stomach, (3) hematoma.
     
  • 85% 4 yr survival if limited disease.
     
  • 25% eligible for surgery provided that the size of the lesion and its vascular involvement, possible mets, and advanced cirrhosis are all considered.
     
  • Resection has 5 yr recurrence rate of 80% and 5 yr survival of 30-60%.
  1. Radiographic findings:
  • Noncontrast CT: hypodense; calcification may be seen.
     
  • Contrast CT: dense, diffuse non-uniform enhancement in arterial phase; some lesions are hypervascular.


  • T1-weighted MRI: usually hypointense to normal liver. When fatty change, fibrosis, or copper is present, variable signal can be seen. With Gd-DTPA, hypervascular lesions enhance early in the arterial phase. (Noncontrast on left; arterial phase middle; late venous phase on right.)

               

  • T2-weighted MRI: typically hyperintense to liver but can be variable. If hemochromatosis is present, the lesion may appear hypointense. A pseudocapsule may be seen.
  • MRA: can be used to assess the patency of the portal vein and IVC.
  1. Screening for HCC in cirrhotic patients:
  • Triphasic CT shows 82% of lesions > 2 cm  in diameter and 60% of lesions < 2 cm in diameter (Lim et al AJR 2000).
     
  • Ultrasound can detect 67% of HCC > 3cm and 12% of HCCs < 3 cm (Bennett et al AJR 2002).
     
  • MRI can detect 80% of lesions >2 cm and 47% of lesions < 2 cm (Krinsky et al Radiology 2001).