Case 200:   Focal Nodular Hyperplasia (FNH)

Diagnostic Category:

Clinical Presentation:

30 year old woman with incidentally found liver mass on CT of the abdomen and pelvis (not shown) done for crampy right lower quadrant abdominal pain.

MR: Central scar, in steatosis

Imaging Findings:

MR demonstrates large FNH in segment 4a with prominent central scar. The lesion demonstrates isointense T2 signal relative to the surrounding hepatic parenchyma with associated hyperintense central scar. It slightly compresses the inferior vena cava. Note that the diffuse hepatic fatty parenchymal infiltration is best appreciated on the opposed-phase image and has decreased compared to the CT done earlier in the clinical course.

On the arterial phase, the lesion demonstrates intense homogenous enhancement, except for the central scar.  On the hepatobiliary phase, the lesion demonstrates hyperintense signal relative to the hepatic parenchyma, while the central scar remains hypointense.