Liver & Biliary Tumors

Liver & Biliary Tumors

Benign:

Hepatic hemangiomas
Focal nodular hyperplasia
Hepatic adenoma.

Malignant:

Hepatocellular carcinoma
Hepatic angiosarcoma
Cholangiocarcinoma.
Metastasize include the breast, lung, and gastrointestinal tract.

Signs/Symptoms:

Liver and biliary tumors are usually asymptomatic, until they become advanced or too large.
Advanced/large: patients may report right upper quadrant discomfort, nausea, bloating, and signs or symptoms of liver disfunction.
Treatment, when necessary, includes resection or transplant; chemotherapy or other treatments may also be necessary.

Benign Tumors - Details

Hepatic hemangiomas are the most common benign liver tumors; that they are mesoderm-derived lesions that comprise malformed blood vessels.
"Cavernous" is the most common subtype, so be aware that these are sometimes called "cavernous hemangiomas."
They can be found as solitary or multiple lesions, and range in size from 1 mm to 50 cm.
Tumors smaller than 5 cm are typically asymptomatic; however, larger tumors can cause discomfort, nausea, and bloating.
Kasbach-Merrit syndrome: "Giant" hemangiomas, those that are 5 cm or greater, are associated with Kasbach-Merrit syndrome.

A life-threatening disorder marked by:

Hemangioma Thrombocytopenia (low platelet count) Disseminated intravascular coagulation (abnormal clotting in vessels depletes clotting factors and causes excessive bleeding).

This is most often due to congenital defects and found in infants.

Focal nodular hyperplasia comprises densely packed hepatocytes fed by an enlarged artery and surrounded by fibrous tissue (note that the nodules are similar to cirrhotic nodules).
These solid tumors are caused by vascular abnormalities; hyper- or hypo-perfusion can induce a regenerative response leading to hyperplasia.
Lesions are usually solitary, and range 4-8 cm in size.
They are more common in women aged 20-50.

Hepatic adenomas (aka, hepatocellular adenomas) are rare epithelial tumors (there are three molecular subtypes).
These tumors are usually solitary, light brown or yellow in color, and soft without a capsule.
They are more commonly found in the right lobe.
These tumors are associated with elevated estrogens (as in oral contraceptive users), anabolic androgens, glycogen storage diseases, and metabolic syndrome.
Although usually asymptomatic, these tumors can rupture and cause acute hemoperitoneum, with severe abdominal pain, hypotension, and shock.

Treat this with transarterial embolization and, if needed, resection.

Malignant tumors - Details

Hepatocellular cancer is in the top ten most common cancers worldwide.
Associated with chronic liver disease, and specifically cirrhosis.

Historically, Hepatitis B and C infections were the most common precursors, but, in western countries, fatty liver disease is a growing cause.

Thus, in patients with chronic liver disease, we do routine surveillance via ultrasound to look for signs of hepatocellular carcinoma – early diagnosis leads to better prognosis:
Early stage 5-year survival rate is about 35%, whereas late stage with metastasis has a 5-year survival rate of only 3%.
Radiological hallmark: wash-in"/"wash-out" with dynamic CT or MRI: during the arterial phase, we see the "wash-in" contrast effect; in the venous phase, we see the "wash-out" effect.

Hepatic angiosarcomas are rare, but aggressive mesenchymal tumors that metastasize to the lungs, spleen, and bone.
They have a high recurrence rate and poor prognosis.
Comprise enlarged anastomosing vascular channels with overgrown endothelial cells.
They are more common in males, and are associated with exposure to environmental toxins, such as vinyl chloride, arsenic, radiation, etc.
They are known to cause spontaneous hemoperitoneum.

Cholangiocarcinomas are biliary tract tumors that are named for their location:

Intrahepatic cholangiocarcinomas are located proximal to the second-order bile ducts.
Perihilar cholangiocarcinomas are located between the second-order bile ducts and the opening of the cystic duct.
Distal cholangiocarcinomas are in the common bile duct distal to the cystic duct opening.

These tumor types have their own unique features, but all are the result of chronic bile duct inflammation that transforms the cholangiocytes.
Common causes of cholangiocarcinoma vary by location:

In Western countries, many cases are caused by primary sclerosing cholangitis.
In Southeast Asia, many cases are caused by flatworm infection.

As we might expect, later stages of cholangiocarcinoma are characterized by jaundice due to biliary tract obstruction.

For references, please see the full tutorial.

Liver & Biliary Tumors

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