Hepatocellular carcinoma is a malignant tumor of the liver, which can be divided into primary liver cancer and metastatic liver cancer.
- Primary liver cancer refers to the liver as the primary site of the tumor and includes hepatocellular carcinoma, cholangiocellular carcinoma, mixed cell hepatocellular carcinoma, and other rare types of liver cancer.
- Metastatic liver cancer usually refers to a history of malignant tumors elsewhere in the body in addition to the liver lesion, or a concurrent malignant tumor elsewhere.
Imaging
In terms of diagnostic imaging, to confirm the presence of a malignant tumor in the liver, imaging is required. The most commonly used imaging tests are enhanced MRI or CT scan, and ultrasonography, with enhanced MRI being preferred.
In patients with primary hepatocellular carcinoma, the imaging has a typical “fast-in-fast-out enhancement pattern,” which is characterized by significant enhancement in the arterial phase and decreased enhancement in the portal and or equilibrium phases, with lower density or signal intensity than in the surrounding liver tissue.
If this typical presentation is found on imaging in a high-risk population (chronic liver disease and/or cirrhosis), the diagnosis of primary hepatocellular carcinoma is clear and histopathologic evidence is not required.
If the tumor is less than 2 cm in diameter, two imaging studies are required for confirmation (enhanced MRI, enhanced CT, ultrasonography); if the tumor is not less than 2 cm in diameter, a typical presentation on one of these imaging studies is sufficient to confirm the diagnosis.
Puncture biopsy
All diagnoses of hepatocellular carcinoma, except for hepatocellular carcinoma with typical imaging, require pathologic confirmation by puncture biopsy on the basis of imaging. Therefore, for this group of patients, liver aspiration biopsy is the gold standard for confirming the diagnosis of hepatocellular carcinoma.
The most important pathological factors affecting the outcome and survival of patients with liver cancer are the biological behavior of liver cancer and the current popular targeted therapies that require genetic testing of the tumor, which must be based on the puncture biopsy of the tumor.
Before puncture biopsy, the diagnosis of malignancy in the liver needs to be confirmed by the usual imaging tests (enhanced MRI or CT scan), of which enhanced MRI is preferred; followed by ultrasound to localize and, if necessary, ultrasonography to localize; and finally by puncture to obtain tumor tissue and obtain a pathological diagnosis.
Laboratory tests
Blood tests can also be used to aid in the diagnosis. For example, elevation of alpha fetoprotein (AFP) is helpful in the diagnosis of primary liver cancer, but it still has a false-negative rate of about 30%, as well as the potential for false positives.
There are many other tumor markers, such as abnormal prothrombin, carcinoembryonic antigen, and CA99, but all of them can only be used as an aid to diagnosis.
In addition, patients are usually checked for hepatitis B and C infection, liver function, and cirrhosis.