MR Imaging Features: ICC vs. HCC vs. combined HCC-ICC

Combined HCC-ICC imaging features overlap with both HCC and ICC features. Overlaps with other malignant or benign lesions are additional pitfalls. Primovist^®-enhanced MRI can give distinctive clues to diagnosis.

Intrahepatic cholangiocarcinomas (ICC) have a worse outcome than HCC. Combined HCC-ICC are rare, and their diagnosis is challenging. Sara Lewis, Icahn School of Medicine at MountSinai, NYC, familiarized her audience with the contrast-enhanced MR imaging appearances of these tumor types.“Be aware that a wide variety of imaging features may occur,” she said.

Frequent Imaging Appearances on Dynamic MRI

• peripheral progressive enhancement: continuously increasing enhancement over time, from the arterial phase (AP) through to the late venous phase (LVP) Additionally, a peripheral biliary distention may appearnext to the lesion. In a cirrhotic liver, progressive-peripheral enhancement may confirm ICC diagnosis.
• solid whole lesion progressive: progressive enhancement on portal-venous phase
• wash-in and washout: arterial phase hyperenhancement and washout in the portal venous and late phase

When to Support Diagnosis of ICC, and When HCC or Combined HCC-ICC?

Additional Clues for Diagnosis

“Always consider additional, clinical and laboratory findings,” Lewis said. Consider combined tumor, if

• a lesion looks like HCC, but CA 19-9 is elevated
• a lesion looks like ICC, but AFP is elevated

Future Diagnosis

The standard of diagnosis is hepatobiliary contrast-enhanced MRI or multiphase CT plus LI-RADS criteria for evaluation. In the near future, quantitative methods and artificial intelligence will gain importance in determining ICC and combined HCC-ICC tumors. Molecular profiling is already an acknowledged method for differentiation.