How should a suspected osteoid osteoma be evaluated?
Osteoid osteoma is a benign neoplasm with a nidus of osteoid-rich tissue that typically causes an intense sclerotic reaction in surrounding bone. An osteoid osteoma may occur in the cortical, cancellous, or periosteal regions of any bone (or rarely in adjacent soft tissues). Most patients are between ages 10 and 30 years and often give a typical history of night pain relieved by aspirin. A radionuclide bone scan may point to the abnormality before any changes are apparent on radiographs and is performed on any patient with a painful scoliosis in whom osteoid osteoma in the spine is the working diagnosis. If radiographs do not reveal the lucent nidus surrounded by sclerotic bone, a computed tomography (CT) scan is the preferred next step because intracortical tumors may be missed on MRI.