Liver Tumors

LIVER TUMORS

Hemangioma is the most common primary tumor of the liver, mostly affecting women. It is a benign vascular tumor that typically forms a subcapsular, red, spongy mass. It is often asymptomatic and detected incidentally on CT or MRI. Resection is rarely indicated, and liver biopsy carries the risk of bleeding.

Hepatocellular adenoma (HCA) affects young women and is related to oral contra-ceptive use. Half of cases are asymptomatic. Symptoms include abdominal pain or spontaneous intraperitoneal hemorrhage (25% of cases). Due to the risk of transfor-mation to HCC, resection is often recommended.

There are 3 subtypes of HCA:

o   H-HCA is a solitary or multiple tan steatotic nodule with rare transformation into HCC

Mutation of hepatocyte nuclear factor 1

o   b-HCA can resemble HCC histologically and transforms to HCC in some cases

Was named for the associated beta-catenin mutations

o   I-HCA shows inflammatory infiltrates, sinusoidal dilatation, and thick-walled arteries

Acute inflammatory markers are elevated; malignant transformation occurs less frequently

Focal nodular hyperplasia is subcapsular lesion often discovered incidentally by the radiologist. Laboratory values are generally normal. It is a nodular proliferation in response to a vascular anomaly. There is a central, stellate scar. Excision is generally not required due to the characteristic appearance on imaging.

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver in adults. The incidence is higher in Asia and Japan than in the United States. Risk factors include cirrhosis, hepatitis B and C viruses, alcohol, aflatoxin B1.

HCC has a tendency for hematogenous spread and invasion of portal and hepatic veins. The tumor marker is α-fetoprotein (AFP).

The fibrolamellar variant affects younger age, has fibrous bands, and has a better prognosis.

Angiosarcoma is a rare, fatal tumor associated with exposure to vinyl chloride.

Hepatoblastoma is the most common hepatic malignancy in infants and children.

Lobectomy is the standard of care. Histology shows immature precursor cells.

Metastatic tumors are the most common tumors found within the liver. Common primary sites include the colon, breast, and lung. Metastatic tumors tend to occur as multiple well-circumscribed masses.