Intraosseous Hibernoma: Five Cases and a Review of the Literature.

We present 5 cases of intraosseous hibernoma, a rare benign tumor of brown fat. Our literature review reveals that the average age at presentation is 58.6 years, and 69.7% of patients are female. Lesions are most often located in the spine and pelvis. Computed tomography usually demonstrates sclerotic changes, although lesions can be lytic. Magnetic resonance imaging findings include heterogeneous T2 hyperintensity. Technetium 99m-methyl diphosphonate bone scan reveals variable radiotracer uptake, whereas 18F-labeled fluoro-2-deoxyglucose (FDG) PET-CT shows mild uptake. Intraosseous hibernoma should be considered when imaging demonstrates a fat-containing lesion in bone, especially one exhibiting FDG avidity.