Hibernoma: MRI features in eight consecutive cases.
OBJECTIVE
To describe the preoperative magnetic resonance imaging findings of eight histologically-proven cases of hibernoma.


METHODS
The site, size, and signal characteristics of eight consecutive hibernomas were retrospectively assessed on T1-weighted spin-echo and short T1 inversion recovery (STIR)/fat-saturated T2-weighted fast spin echo magnetic resonance images. Four patients also had gadolinium-enhanced fat-saturated T1-weighted spin echo imaging. Patient age and sex, and duration of symptoms were recorded.


RESULTS
Three female and five male patients with an average age 36 years (range 16-53 years) were included. Seven lesions occurred in the thigh, four in the anterior compartment and three in the posterior compartment. One lesion occurred superficial to the scapula. All cases demonstrated common magnetic resonance imaging findings of a well-defined, heterogeneous mass, slightly or clearly hypo-intense to subcutaneous fat on T1-weighted spin-echo images, with prominent thin low signal bands throughout the tumour. The lesions failed to fully suppress on STIR or fat-saturated T2-weighted images. Only one of the four contrast-enhanced studies demonstrated increased vascularity in the tumour.


CONCLUSIONS
The MRI findings of a lesion that is diffusely slightly hypointense to surrounding subcutaneous fat, should prompt the operator to consider hibernoma in the differential diagnosis.
Lee
J C
JC
Department of Radiology, The London Bone and Soft Tissue Tumour Service, London, UK.
Gupta
A
A
Saifuddin
A
A
Flanagan
A
A
Skinner
J A
JA
Briggs
T W R
TW
Cannon
S R
SR
D052437:Adipocytes, Brown / Q000473:pathology*; D000273:Adipose Tissue; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008067:Lipoma / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012540:Scapula; D013848:Thigh