Dumbbell-shaped thoracic hibernoma: computed tomography and magnetic resonance imaging findings.

Hibernoma is an uncommon, benign soft tissue tumor that arises in brown adipose tissue. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of hibernomas are similar to those of well-differentiated liposarcoma or angiolipoma. We report the unique appearance of a rare thoracic wall hibernoma, which appeared as a dumbbell-shaped lipomatous tumor across an intercostal region. A dynamic contrast-enhanced study on MRI revealed early enhancement, which corresponded to the branching low-signal intensity on T2-weighted images of the mass.