Intraosseous hibernoma: a potential mimic of metastatic carcinoma

Intraosseous hibernoma is a rare benign bone tumor, with only 3 cases reported in English literature. In this report, we describe a 50-year-old woman with a history of stage IIB breast cancer and posterolateral right hip pain. Imaging studies showed a sclerotic lesion in the right ilium, which was biopsied and showed mildly thickened bone trabeculae and multivacuolated brown fat cells replacing the normal white fat and hematopoietic elements, diagnostic of intraosseous hibernoma.