Liver and Biliary Tract Tumors for USMLE Step 3
Liver and Biliary Tract Tumors for the USMLE Step 3 Exam
Liver Tumors
- Hepatocellular Carcinoma (HCC):
- Epidemiology:
- The most common primary liver malignancy, constituting 80-90% of liver cancers.
- Associated with cirrhosis due to chronic hepatitis B, hepatitis C, alcoholic liver disease, and nonalcoholic steatohepatitis (NASH).
- Risk Factors:
- Chronic hepatitis infections, cirrhosis, alcohol use, aflatoxin exposure, and hereditary hemochromatosis.
- Clinical Presentation:
- Often asymptomatic in early stages.
- Symptoms include weight loss, abdominal pain, jaundice, and ascites in more advanced disease.
- Diagnosis:
- Multiphasic CT or MRI with arterial enhancement and venous washout is diagnostic.
- Elevated alpha-fetoprotein (AFP) is a tumor marker.
- Treatment:
- Surgical resection or liver transplantation for early-stage disease.
- Transarterial chemoembolization (TACE) for intermediate-stage and sorafenib for advanced disease.
- Hepatic Adenoma:
- Epidemiology:
- Benign liver tumor often related to oral contraceptive use.
- Primarily occurs in young women.
- Clinical Presentation:
- Often asymptomatic but may present with abdominal pain or hemorrhage if large.
- Diagnosis:
- MRI with gadolinium shows hypervascular lesions.
- Treatment:
- Discontinuation of oral contraceptives and surgical resection if >5 cm or symptomatic, to prevent rupture or malignancy.
- Focal Nodular Hyperplasia (FNH):
- Epidemiology:
- Benign liver lesion commonly found in women, often incidentally.
- Clinical Presentation:
- Usually asymptomatic.
- Diagnosis:
- MRI showing a central scar with arterial enhancement.
- Treatment:
- No treatment required unless symptomatic.
Biliary Tract Tumors
- Cholangiocarcinoma:
- Epidemiology:
- A malignancy of the bile ducts; can be intrahepatic or extrahepatic.
- Associated with primary sclerosing cholangitis (PSC), choledochal cysts, and liver fluke infections.
- Clinical Presentation:
- Painless jaundice, pruritus, and dark urine are common with extrahepatic disease.
- Abdominal pain is more common in intrahepatic disease.
- Diagnosis:
- MRI/MRCP or CT reveals bile duct obstruction.
- CA 19-9 is elevated but not specific.
- Treatment:
- Surgical resection is the only curative option for early disease.
- Adjuvant chemotherapy (gemcitabine, cisplatin) is often used.
- Gallbladder Cancer:
- Epidemiology:
- A rare but aggressive biliary malignancy.
- Associated with chronic gallstone disease, porcelain gallbladder, and chronic cholecystitis.
- Clinical Presentation:
- Often asymptomatic until late, presenting with right upper quadrant pain, jaundice, and weight loss.
- Courvoisier sign (palpable, painless gallbladder) indicates obstruction.
- Diagnosis:
- Ultrasound or CT detects gallbladder masses.
- Treatment:
- Surgical resection for localized disease.
- Chemotherapy or radiation for advanced or unresectable cases.
Key Points
- Hepatocellular carcinoma (HCC) is the most common liver cancer, associated with cirrhosis from chronic liver disease. Imaging and AFP levels are used for diagnosis, with treatment depending on the stage, including resection, transplantation, and systemic therapies.
- Hepatic adenoma is linked to oral contraceptive use and may require surgical resection if large or symptomatic due to the risk of hemorrhage or malignant transformation.
- Cholangiocarcinoma often presents with painless jaundice and is associated with conditions like PSC. Surgical resection offers the best chance for cure.
- Gallbladder cancer is rare and linked to chronic gallstone disease, presenting with right upper quadrant pain and jaundice in advanced stages.