Primary osteogenic sarcoma of the spine.

Primary osteogenic sarcoma of the spine is a rare tumor making up 0.85% to 2.0% of all osteogenic sarcomas. The majority (29/41) of previously reported cases have occurred in vertebrae affected by Paget disease or radiation exposure. Two cases of osteogenic sarcoma of the spine, one lumbar, the other thoracic, with no known predisposing factors are presented.