- Hepatocellular carcinoma (HCC) is the most common primary malignant hepatic neoplasm.
- Underlying cirrhosis from alcoholism, hepatitis (B and C), and toxin exposure are the predominant causal factors.
- The serum alpha-fetoprotein level is usually elevated in patients with HCC.
 Imaging Findings
- On T1-weighted MR images, HCC is most often hypointense relative to the liver, although hyperintense lesions or areas of hyperintensity within hypointense lesions may be seen.
- These hyperintense regions within the HCC reflect the presence of fat, copper, protein, or blood secondary to intralesional hemorrhage.
- On T2-weighted images, HCC is generally hyperintense, although well-differentiated lesions that are isointense relative to the liver parenchyma may be seen.
- Most HCCs show intense enhancement on arterial phase contrast-enhanced images.
- A large HCC (>5 cm) may have a number of characteristic features, such as a mosaic pattern, a tumor capsule, extracapsular extension with formation of satellite nodules, vascular invasion, and extrahepatic dissemination, including lymph node and distant metastases.
- The mosaic pattern is created by confluent small nodules separated by thin septa and necrotic areas within the tumor. This pattern is more often depicted on T2-weighted MR images than on T1-weighted images.
 See Also
 External Links
- Khaled M. Elsayes, Vamsidhar R. Narra, Yuming Yin, Govind Mukundan, Markus Lammle, and Jeffrey J. Brown. Focal Hepatic Lesions: Diagnostic Value of Enhancement Pattern Approach with Contrast-enhanced 3D Gradient-Echo MR Imaging. RadioGraphics 2005 25: 1299-1320.