Hepatocellular Carcinoma

• The 1st image is CT of liver during arterial phase. The 2nd image is during the portal venous phase and the third is during the delayed phase. This lesion is in a patient with Hepatitis B. With this enhancement pattern, the most likely diagnosis is hepatocellular carcinoma.
  
  
• Hepatocellular Carcinoma - malignant tumor of hepatocellular origin (duh)


• Most common primary malignancy of the liver


• Most commonly found in diseased livers - cirrhosis of any cause (such as alcohol), viral hepatitis, and metabolic liver disease (America - alcohol, steroid use, hemochromatosis)


• Commonly invade vascular system - especially the portal vein


• No fibrous stroma - hemorrhage and necrosis - can rupture and cause hemoperitoneum


• 3 common growth patterns - solitary, multiple nodules, diffuse infiltrative


• Presentation - fever of unknown origin, abdominal pain, malaise, hepatomegaly


• AFP can be elevated (and often is - 70-80% or so); like to see >400; >1000 can be presumptive in correct clinical setting


• Can produce paraneoplastic syndromes - erythrocytosis, hypoglycemia, hypercalcemia, hirsutism


• CT - look for signs of cirrhosis, hemochromatosis etc; arterial - hyper enhancing; PV - iso to hypodense; delayed - often iso maybe hypo - sometimes a capsule is shown


• MRI - considered the favored study - T1 - iso, hyper, hypo to liver; T2 - usually hyper; superparagmagnetic iron - may help because no or few kupffer cells;


• US - variable appearance and small ones can look like hemangioma (bright/echogenic) - larger are usually heterogenous in echogenicity
• Rare associations - thorotrast, primary sclerosing cholangitis, primary biliary cirrhosis, OCP's, 1-antitrypsin deficiency, porphyria cutanea tarda

Treatment - Percutaneous alcohol, RF ablation, TACE but definitive is transplant

Differentials - dysplastic nodules and regenerative nodules. Also consider Hemangioma and focal confluent fibrosis.

Regenerative - rarely 2cm or greater. Can be siderotic or nonsiderotic. Siderotic nodules if large enough are hyperdense nodules in the liver on noncontrast and enhance like normal liver. Siderotic may be dark on T1 and T2 (esp T2). Nonsiderotic might be bright on T1.

Dysplastic nodules - precursor to HCC. Can enhance similar to HCC but don't usually. Often bright on T1 and dark on T2.

references - emedicine.com and Radiographics. 2001;21:S117-S132. Images from Rob's Radiology collection. Please do not copy without permission.