What is an osteoblastoma?

Also called giant osteoid osteoma, osteoblastomas are larger than (but histologically comparable to) osteoid osteomas. In addition to size differences, however, osteoblastomas are more vascular, have higher numbers of osteoblasts, and are less organized than osteoid osteoma. Patients are typically younger than 30 years. Osteoblastomas are rare.