<unk>  <unk> , is a non-cancerous bone tumor composed of multiple varying sizes of spaces in a bone which are filled with blood. The term is a misnomer, as the lesion is neither an aneurysm nor a cyst. It generally presents with pain and swelling in the affected bone. Pressure on neighbouring tissues may cause compression effects such as neurological symptoms. The cause is unknown. Diagnosis involves medical imaging. CT scan and X-ray show lytic expansion lesions with clear borders. MRI reveals fluid levels. Treatment is usually by curettage, bone grafting or surgically removing the part of bone. 20-30% may recur, usually in the first couple of years after treatment, particularly in children. It is rare. The incidence is around 0.15 cases per one million per year.<unk>  was first described by Jaffe and Lichtenstein in 1942.
Aneurysmal bone cyst
Bone cyst
Osteoid osteoma
Unicameral bone cyst
Juvenile active ossifying fibroma
Osteoma
Osteochondroma
Peripheral ossifying fibroma