Osteoid osteomas and osteoblastomas of the spine.

OBJECT: Osteoid osteomas and osteoblastomas are rare primary bone tumors that usually do not arise in the spine. In this report the authors analyze 16 cases of osteoid osteoma or osteoblastoma of the spine that were surgically treated over a 27-year period.

METHODS: A retrospective study was conducted in which the following data were found: five patients had osteoid osteomas (two male and three female patients) and 11 had osteoblastomas (seven male and four female patients). The site of the tumor was the cervical spine in four, thoracic in six, and lumbar spine in six. In 14 patients, the tumor involved the posterior vertebral elements, with lumbar and thoracic levels being the most common. Only two patients had tumors in the body of a cervical vertebra. The mean age of the patients was 20 years for osteoid osteoma and 19 years for osteoblastoma. The most common symptom was local pain in the area of the tumor. Among 11 patients with osteoblastoma, six (two with paraparesis, four with monoparesis) had neurological deficits caused by extradural compression. None of the patients with osteoid osteoma had neurological deficits. The diameters of osteoblastomas were 3 to 8 cm (mean 4 cm), and those of osteoid osteomas were 1.5 to 2 cm (mean 1.7 cm). Although the peritumoral bone was normal in patients with osteoblastoma, a sclerotic rim was observed in all patients with osteoid osteoma. All patients were treated with resection; tumor excision was complete in 15 cases. Follow-up periods ranged from 2 months to 13 years (mean 36 months). Complete pain relief was achieved in 15 patients; the other patient described mild pain with activity. There was no tumor recurrence except one regrowth in a patient with osteoblastoma who then received radiation therapy. There were two complications: one surgery was performed at the wrong level, and there was one instrument failure that required revision.

CONCLUSIONS: With the help of modern imaging modalities that aid in diagnosis and surgical planning, a complete removal and cure may be achieved for most of these rare tumors.