Fibrolamellar hepatocellular carcinoma--an atypical MR manifestation

We report the imaging findings, specifically magnetic resonance pictures of a non-cirrhotic case of fibrolamellar hepatocellular carcinoma in an older patient (60 years). Computed tomography revealed non-enhanced hypodense central scar without notable intratumoral calcification. MR imaging revealed a mass, which was homogeneously hypointense on T1-weighted images (T1WI) and turned hyperintense on T2-weighted images (T2WI). Stellate central scar was depicted with more hypointensity on T1WI, however, it became markedly hyperintense on T2WI. This manifestation is very different from the typical pattern reported in the literature. In gadolinium enhanced T1WI, the mass other than the central scar got enhanced. Fibronodular hyperplasia and fibrolamellar hepatocellular carcinoma should be differentiated with reference to the clinical and imaging findings. Collagenous central scar was described pathologically within the latter. However, a discrepancy between the pathological and magnetic resonance pattern concerning the central scar which was collagenous and corresponding to hyperintensity on T2WI was found. To our knowledge no similar entity has been described in the literatures so far.