Cervical hibernoma.

The hibernoma is a rare neoplasm derived from vestigal remnants of brown fat left from early embryologic development. Review of the world literature reveals only 40 cases to which we are adding a report of a tumor arising in the posterior cervical triangle of a 20-year-old man. The distribution, histology and cytochemistry of brown fat and the hibernoma are discussed, and evidence supporting its histogensis is presented.