Background:
Fat can be identified in numerous liver lesions, and usually is not a specific
finding. Distinguishing between different kinds of fatty deposits is an important part of differential
diagnosis. Magnetic Resonance Imaging (MRI) is superior to other imaging techniques because
it allows distinguishing intracellular from macroscopic fat.
Discussion:
Intracellular lipid may be found in focal hepatic steatosis, hepatic adenoma, hepatocellular
carcinoma and, less commonly, in focal nodular hyperplasia as well as regenerative and dysplastic
nodules. Macroscopic fat is seen in angiomyolipoma, lipoma, metastases from fatcontaining
neoplasms, primary or metastatic liposarcoma, hydatid cyst, pseudolipoma of the Glisson
capsule, pericaval fat collection, lipopeliosis, hepatic teratoma, focal hepatic extramedullary
haematopoiesis and adrenal rest tumour.
Conclusion:
Liver nodules should be characterised with regard to underlying liver condition, MRI
characteristics and contrast enhancement pattern, including hepatobiliary phase. In many cases,
identification of fatty content may help narrowing the differential diagnosis.