Bisphosphonate treatment in inaccessible osteoid osteomas: An alternative therapeutic approach.

Introduction: Osteoid osteoma is a benign osteogenic tumour traditionally treated by surgical excision or percutaneous CT-guided procedures. We describe three cases of osteoid osteomas of which the locations were difficult to access, or for which the procedure was potentially unsafe, involving treatment with zoledronic acid infusions.

Case Description: We report here three male 28-to-31-year-old patients with no medical history who had osteoid osteomas located at the second cervical vertebra, the femoral head, and the third lumbar vertebra respectively. These lesions were responsible for inflammatory pain requiring daily treatment with acetylsalicylic acid. Given the impairment risk, all of the lesions were ineligible for surgical or percutaneous treatment. Patients were successfully treated by 3 to 6 monthly zoledronic acid infusions. All patients experienced complete relief of their symptoms allowing aspirin discontinuation, without any side effects. In the first two cases, CT and MRI control showed nidus mineralization and bone marrow oedema regression, correlating with the pain decrease. After 5years of follow-up, there had been no recurrence of the symptoms.

Conclusion: In these patients, monthly 4mg zoledronic acid infusions have been safe and effective in the treatment of inaccessible osteoid osteomas.