Imaging findings of a hibernoma of the neck.

Hibernoma is an uncommon benign fatty tumor that arises from the vestiges of fetal brown fat. We present a case report of a hibernoma of the neck in an asymptomatic 19-year-old girl and describe the important imaging findings. Computed tomography (CT) shows a well defined hypodense mass with septations. Magnetic resonance imaging (MRI) shows intermediate T1 and bright T2 signal of the mass and also demonstrates the characteristic marked contrast enhancement.