Intraosseous lipoma.

Intraosseous lipoma is the rarest benign primary tumor of bone. The incidence is less than one per 1,000 bone tumors. Because of its rarity and non-specific clinicopathologic findings, large biopsy specimens are needed for an accurate diagnosis. Once diagnosis has been established, a conservative treatment protocol is mandatory. The prognosis is generally excellent, and recurrences have not been reported.