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:
- 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.