Cervicomediastinal hibernoma.

Hibernoma is a benign soft-tissue tumor, derived from the brown fat, that often presents as a painless, slow-growing mass. About 100 cases of hibernomas have been reported in the world literature. Seven cases of intrathoracic hibernoma are reported, of which only 1 was located in the mediastinal region. That tumor was an intramediastinal hibernoma with a cervicomediastinal location, which was excised through an extended left supraclavicular incision without the necessity to perform a sternotomy. No recurrence was evident after 18 months.