Pediatric cervicomediastinal hibernoma: a case report.

Hibernoma is a rare lipomatous tumor of brown fat origin. Though uniformly benign in nature these tumors may cause symptoms secondary to extrinsic compression of neighboring structures. Hibernomas may be found anywhere that normal fetal brown fat may be located but are most commonly located in the thigh. We present a case of a hibernoma presenting as an unusual cervicomediastinal mass in a 6-year-old male. This mass was discovered during a diagnostic chest x-ray for pneumonia and treated by resection. Complete surgical resection is considered curative. Hibernoma should be considered in the differential diagnosis of any lipomatous tumor.