[Mediastinal hibernoma: singular appearance on computed tomography].

Hibernomas are very uncommon benign tumors of brown fat; they are rarely located within the thorax and are even rarer in the mediastinum. We present the case of a 14-year-old girl with a hibernoma seen on CT as a homogeneous fat density mass located in the anterior mediastinum. Histological study revealed the typical microscopic characteristics of these tumors. To our knowledge, this is the first report of these CT imaging characteristics in association with a hibernoma.