Definition:

Variant of HCC with permeative growth pattern

Comments:

• Features suggestive of infiltrative HCC include (partial list):
• Heterogeneous attenuation/signal intensity
• Mild to moderate T1 hypointensity not attributable to edema
• Mild to moderate T2 hyperintensity not attributable to edema or, on non-fat-suppressed T2w images, hepatic fat deposition
• Mild to moderate restricted diffusion
• Heterogeneous enhancement in one or more phases
• Obscured or non-visualized veins not attributable to chronic benign occlusion
• Architectural distortion
• Tumor in vein

• At imaging, infiltrative HCC may manifest as a diffuse ill-defined mass, often involving more than one segment.
• Infiltrative HCCs may be difficult to detect in the cirrhotic liver at CT and MRI. Pre-contrast imaging may be helpful. Careful analysis of all available images frequently is necessary.