<unk>  <unk>  accounts for 1% to 2% of all primary bone tumors. The incidence of<unk>  is approximately 0.14 per 100,000 individuals worldwide. Adolescents and children are most affected by<unk> . The age distribution of<unk>  is between 1.5-25 years. The mean age of the patients with<unk>  is 16 years. Women are more commonly affected than men, with a 1:0.84 ratio. In 1942, Jaffe and Lichtenstein first described<unk> .<unk>  can be classified based  on mechanism of origin into primary and secondary. The true causes of<unk>  are not known.<unk> s usually present in the long bones such as the humerus, femur, tibia and fibula. About 25% of<unk> 's are seen in posterior element of spine.<unk> 's typically occur in the metaphysis of the long bones. The hallmark of<unk>  is Pain, swelling and pathological fracture. The mainstay of treatment for<unk>  is surgery in form of curettage and bone grafting.
Aneurysmal bone cyst
Osteoid osteoma
Unicameral bone cyst
Osteoma
Osteochondroma
Osteochondrosis
Primary lymphoma of the bone
Myositis ossificans