Hibernoma

Comments:
A benign lipomatous tumor usually seen in the intercapsular region, axilla and the thigh. It may also occur in the mediastinum and the retroperitoneum. The cut surface is brown. It resembles the brown fat of the hibernating glands of some animals. Note the contrast with mature yellow adipose tissue to the right. Image courtesy of: Dr. Holger Moch, Department of Pathology, University Hospital Zurich, 8091 Zurich, Switzerland.