False-positive findings on 18F-FDG PET/CT: differentiation of hibernoma and malignant fatty tumor on the basis of fluctuating standardized uptake values.
OBJECTIVE
Hibernoma is a benign tumor of brown fat that has imaging features similar to those of malignant fat-containing soft-tissue tumors. Hibernoma is metabolically active on (18)F-FDG PET/CT, and its presence can lead to false-positive interpretations. We present three cases in which fatty lesions with increased radiotracer uptake identified on FDG PET/CT turned out to be hibernomas. The standardized uptake values of the lesions were similar to those reported in the literature for liposarcoma. However, all three patients had variable standardized uptake values over time.


CONCLUSIONS
Variation in standardized uptake values over time is an imaging characteristic that may be helpful for differentiating hibernoma and malignant fatty tumor.
Smith
Clare S
CS
Department of Radiology and Nuclear Medicine, Memorial Sloan Kettering Cancer Center, 1275 York Ave., New York, NY 10021, USA.
Teruya-Feldstein
Julia
J
Caravelli
James F
JF
Yeung
Henry W
HW
D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008067:Lipoma / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D018205:Neoplasms, Adipose Tissue / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18