Hibernoma: a case report demonstrating usefulness of MR angiography in characterizing the tumor.

Hibernoma is a rare, benign soft-tissue tumor composed of brown fat. In the past, there has been an extensive discussion of the CT attenuation and MRI signal characteristics of hibernomas. However, recent reports have focused upon the tumor vascularity of hibernomas. We describe the only case in the literature which utilizes state of the art contrast enhanced MR angiography to clearly characterize the surface and intratumoral vessels to help confirm the diagnosis of a hibernoma and aid in the preoperative planning.