LI-RADS 5 lesion

Case contributed by Dr Matt A. Morgan


History of chronic hepatitis B. Lesion below detected on asymptomatic screening.

Patient Data

Age: 70 years
Gender: Male

LI-RADS 5B lesion

Classic imaging appearance of a LI-RADS 5 lesion (definitely hepatocellular carcinoma).  This lesion was not present on an MRI performed ~9 months earlier.

  • T2 fat sat : mild hyperintensity of the lesion
  • precontrast phase: mild hypointensity of a peripheral ovoid lesion in the right hepatic lobe
  • arterial phase: intense enhancement of the 2.6 cm lesion (late arterial phase)
  • portal venous phase: decreased enhancement of the lesion on the portal venous phase with a faint capsule remaining; the lesion now appears to be isointense to background liver

Case Discussion

LI-RADS is a classification system for communicating the likelihood of a hepatic lesion being hepatocellular carcinoma (HCC) in an at-risk liver. Like BI-RADS for breast imaging, the idea of the classification system is to take a wide variety of possible findings on CT or MRI and condense them into prognostic and treatment groups that will not vary from institution to institution.

The lesion in this case is classic for a LI-RADS 5 lesion, which is the most suspicious category and defined as "definitely HCC". The lesion fulfills three out of four major criteria to make it level 5:

  • non-rim arterial phase enhancement
  • presence of an enhancing "capsule" 
  • interval growth

The lesion demonstrates decreased enhancement on the postcontrast sequence, but there is not much "wash out" (hypoenhancement relative to background liver on portal venous and delayed postcontrast dynamic sequences).  Instead, the lesion shows signal isointensity to the background liver.  This may cause confusion in diagnosing the lesion because one may wonder if the lesion is really washing out and whether this should really definitely be called an HCC... but the LI-RADS classification only requires one of the major criteria ("wash out", capsule, interval growth) to be considered "definitely HCC" in this setting.  Thus, although "wash out" is slightly ambiguous, this is definitely an HCC.

Because it is a LI-RADS 5 lesion, biopsy is unnecessary. Radiologic T-staging should be pursued, with treatment, if possible.

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Case information

rID: 32877
Published: 19th Dec 2014
Last edited: 18th Aug 2020
Inclusion in quiz mode: Included

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