Hepatocellular carcinoma may appear as a solitary mass, multiple masses, or a diffuse pattern. The diffuse pattern accounts for only 6% of all hepatocellular carcinomas and is almost always associated with cirrhosis. Solitary and multiple masses make up the rest of cases and occur at about an equal rate.
The appearance of hepatocellular carcinoma can vary greatly. If the tumor is less than 3 cm, the mass will usually appear hypoechoic. When the mass is greater than 5 cm, an inhomogeneous echo pattern is most common. Acoustic enhancement may be seen, as well as lateral acoustic shadows behind the outer edges of the tumor. Other possible findings include portal vein thrombosis, hepatic vein thrombosis, inferior vena caval, and occasional right atrium invasion. About 10% will show calcification and about 8% will have lymphadenopathy. Abscess formation has been reported.
Ultrasound underestimates the extent of the tumor about 1/3 of the time. About 1/4 of the tumors become visible or are better seen on a contrast-enhanced CT. This is shown in Patient C. Conversely, as shown in Patient A, contrast-enhanced CT may at times make a hepatocellular carcinoma isodense and invisible.
Hepatocellular carcinoma accounts for only 0.5% of all tumors at autopsy. They account for 80 to 90% of all primary liver tumors; however metastases are 20 times more common than a primary tumor. Hepatocellular carcinoma is 2 to 4 times more common in men than in women, believed to be related to testosterone. Sixty to 70% of all hepatocellular carcinoma are associated with cirrhosis.
Causes of hepatocellular carcinoma:
2. Chronic liver disease
A. Alcoholic and postnecrotic cirrhosis
B. Alpha 1 antitrypsin deficiency
D. Hereditary tyrosinosis
3. Mycotoxins (metabolites of Saprophytic fungi)
The clinical features include hepatomegaly, upper abdominal pain, bruit over the liver, hemoperitonium, anemia, elevated alkaline phosphatase, and elevated alpha fetoprotein. Patients with hepatocellular carcinoma have a one-year survival of 21.5% and a 5-year survival of 2.4%. Most die from GI bleeding. Hepatocellular carcinomas most commonly spread to the lungs, local lymph nodes, or, rarely, to the adrenal glands.