[Osteoid osteoma of the spine and pelvic area]

We describe 8 cases of osteoid osteoma of the spine and the pelvis. In the rare cases of this tumor the clinical symptoms are not specific. The typical nocturnal exacerbation of the pain was absent in 2 of our 8 patients. More often the main symptoms were abnormalities of the gait or deformation of the spine, partly secondary to the often absent pain. Pain relief after aspirin is described but not constant. The aspirin test was positive in 4 of our 8 cases (in 20-50% of the cases in the literature). It must be emphasized that conventional-x-ray is often not diagnostic, and therefore the diagnosis is often delayed. If there is suspicion of osteoid osteoma a technetium bone scan should be performed. CT-scan is required for preoperative evaluation. Treatment of choice is the excision of the tumor in healthy tissue, which was successful in all our 8 cases.