Vertebral osteoblastoma: Are radiologic structural changes necessary for diagnosis?

BACKGROUND A case of osteoblastoma localized at the pedicle of the 10th thoracic verte bra is presented. CASE DESCRIPTION The patient complained of nocturnal back pain not relieved by salycilates, a typical symptom of osteoblastoma. Bone scintigraphy showed a lower thorac ic focus of increased osteoblastic activity; however, X-rays, computed tomo graphy, and magnetic resonance images (MRI) were within normal limits, show ing only obscure changes that were also noted in the rest of the spine. Rep eat MRI with contrast revealed a focal enhancement. After pediculectomy, hi stopathologic examination confirmed the diagnosis of osteoblastoma. Fifteen months postoperatively, the patient is symptom-free. CONCLUSION Our case demonstrates that some cases of osteoblastoma may not have the cla ssical radiological appearance. Although non-contrast computed tomography a nd T1-weighted MRI are mildly positive in some instances, osteoblastoma is best visualized on MRI with gadolinium. Like any other neoplasm, osteoblast oma should be detected and removed early, before it can cause structural bo ny changes. (C) 1999 by Elsevier Science Inc.