Osteoblastoma in the skeletally immature

BACKGROUND: Osteoblastoma is a rare benign and sometimes locally aggressive tumor with peak incidence in the second decade. None of the available series addresses specifically the differences in presentation, management, and outcome between the pediatric and adult patient populations. METHODS: The medical records and radiographs of all children diagnosed with osteoblastoma during a 17-year period were reviewed. We recorded demographic information, time until diagnosis, location, clinical and radiographic characteristics, treatment, complications, and outcome at a minimum 2-year follow-up (range, 2-5 years). RESULTS: Seventeen children met the inclusion criteria. There were 10 boys and 7 girls, with an average age at diagnosis of 11 years (range, 20 months-15 years). The average time delay between onset of symptoms and diagnosis was 6.5 months (range, 2 months-2 years). There were 7 lesions in the lower extremity, 5 in the spine, 4 in the upper extremity, and 1 in the sternum. Pain at the tumor site was present in all cases. Two of the 5 patients with spine lesion had scoliosis. All patients underwent open incisional biopsy with intraoperative frozen section. In 16 cases, this was followed by a 4-step approach (extended curettage, high-speed burring, electrocauterization of cavity wall, and phenol 5% solution). Four of the 5 patients with spine lesions had instrumented posterior spine fusion after tumor removal. Two patients were referred to our institution with recurrent lesion after surgery elsewhere. Only 1 (6%) of 15 children initially treated at our institution had recurrence. All recurrences occurred in children younger than 6 years; all were successfully treated with a 4-step approach. CONCLUSIONS: Osteoblastomas can be successfully treated with a 4-step approach. Children younger than 6 years may have a higher likelihood of recurrence.