It is rare. The incidence is around 0.15 cases per one million per year. 80% occur in people age less than 20 years. It is second most common tumor of spine and most common benign tumor of pelvis in pediatric population. Males are affected as equally as females.
Aneurysmal bone cyst
Bone cyst
Osteoid osteoma
Unicameral bone cyst
Juvenile active ossifying fibroma
Osteoma
Osteochondroma
Peripheral ossifying fibroma