MR findings of steatotic focal nodular hyperplasia and comparison with other fatty tumours.
OBJECTIVE
To correlate MR findings with pathology in steatotic FNHs and to compare the MR findings with those of other fatty tumours developed on noncirrhotic liver in a consecutive series of resected lesions.


METHODS
Our population included resected FNH with intralesional steatosis (n = 25) and other resected fatty tumours selected as controls (hepatocellular adenomas and angiomyolipomas, n = 34). Lesions were classified into three groups: those with typical FNH without (group 1) or with (group 2) fat on MR and those with atypical lesions (group 3). In group 3, diagnostic criteria for other fatty tumours were applied.


RESULTS
There were 9 lesions in group 1 (15.3 %), 4 in group 2 (16.8 %) and 46 in group 3 (77.9 %). Group 3 contained 12 FNHs (26 %) and all the other fatty tumours. In group 3, the association of lesion homogeneity, signal intensity similar to or slightly different from adjacent liver on in-phase T1- and T2-weighted sequences, and strong arterial enhancement was observed in 7/12 (58 %) of steatotic FNHs and 3/34 (9 %) of other tumours.


CONCLUSIONS
On MR, fat within a typical FNH should not reduce the diagnostic confidence. We recommend further investigations including liver biopsy if necessary when fatty tumours exhibit atypical MR findings.
Department of Radiology, University Paris Diderot, Sorbonne Paris Cité, University Hospitals Paris Nord Val de Seine, Beaujon, 100 bd General Leclerc, 92118 Clichy, Hauts-de-Seine, France. Maxime.ronot@bjn.aphp.fr
Maxime
M
Ronot
Valérie
V
Paradis
Rafael
R
Duran
Anne
A
Kerbaol
Marie-Pierre
MP
Vullierme
Jacques
J
Belghiti
Dominique-Charles
DC
Valla
Valérie
V
Vilgrain
D000328:Adult; D005234:Fatty Liver / Q000150:complications / Q000473:pathology*; D020518:Focal Nodular Hyperplasia / Q000150:complications / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000150:complications* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity