<unk>  is a rare benign neoplasm of the bone, which constitutes for almost 1% of all primary bone tumors and 3% of all benign tumors in the United States. One-third of patients have lesions in the posterior elements of the spine, most often the lumbar and sacral regions. In 1952, Lichtenstein first termed the lesion as osteogenic fibroma of bone. In 1956, Lichtenstein and Jaffe in their independent detailed studies of this neoplasm renamed the lesion as<unk> .<unk>  might be conventional benign or aggressive and malignant. The exact etiology of<unk>  is unknown. The<unk> s are more aggressive compared to the other benign tumors of the musculoskeletal system. Histologically<unk>  is similar to osteoid osteoma and is differentiated on the basis of its large size.<unk>  is a benign tumor of the musculoskeletal system and is associated with little morbidity. The risk factors are not yet established and there is insufficient evidence to recommend routine screening for<unk> . If not treated, it may grow and damage the bone and adjacent structures. If the untreated<unk>  invades the spinal canal or neural foramina, it may lead to progressive neurologic deficits. Once the tumor expands outside the bone, the recurrence rate of<unk>  reaches to nearly 20%. Biopsy is the diagnostic study of choice for the diagnosis of<unk>  which shows similar features to that of osteoid osteoma. The majority of patients with<unk>  have a positive history of pain which is dull and achy in nature, and the pain is not relieved by salicylates. There are no diagnostic laboratory, ECG, echocardiography or ultrasound findings associated with<unk> . X-ray is a useful diagnostic tool in the diagnosis of<unk>  and may reveal a well circumscribed radiolucent lesion in the bony cortex. CT scan may be helpful in the diagnosis and management of<unk>  and may provide the size and extent of<unk> . MRI may be helpful in determining the extent of<unk>  that has invaded the surrounding soft tissues, bone marrow, and spine. The most sensitive radiographic examination for the evaluation of<unk>  is bone scan. The angiography is performed if the information about the adjacent major ve sel locations or its involvement is needed. Surgery is the mainstay of treatment for<unk>  and the treatment with chemotherapy and radiation therapy are still controversial.
Osteoblastoma
Osteoma
Osteochondroma
Osteosarcoma
Osteoid osteoma
Brown tumor
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Chondrosarcoma