Osteoblastoma

A rare, neoplastic disease characterized by a typically benign, locally aggressive, non self-limiting, osteoblastic bone tumor, usually located on the spine, proximal humerus and hip (although any bone may be involved), generally manifesting with slowly progressive, dull aching pain which is difficult to localize and is not relieved by nonsteroidal anti-inflammatory drugs or aspirin. Neurologic symptoms, such as cranial nerve palsies, myelopathy, neuralgia, radiculopathy, paraparesis or paraplegia, may be associated if the spine is involved. Imaging reveals a lytic (or mixed lytic and blastic) lesion with a radiolucent nidus (> 2 cm) associated with reactive sclerotic bone.