Clinicoradiological diagnosis of benign osteoblastoma of the spine in children

Osteoblastomas of the spine: a comprehensive review

Osteoblastomas are primary bone tumors with an affinity for the spine. They typically involve the posterior elements, although extension through the pedicles into the vertebral body is not uncommon. Histologically, they are usually indistinguishable from osteoid osteomas. However, there are different variants of osteoblastomas, with the more aggressive type causing more pronounced bone destruction, soft-tissue infiltration, and epidural extension. A bone scan is the most sensitive radiographic examination used to evaluate osteoblastomas. These osseous neoplasms usually present in the 2nd decade of life with dull aching pain, which is difficult to localize. At times, they can present with a painful scoliosis, which usually resolves if the osteoblastoma is resected in a timely fashion. Neurological manifestations such as radiculopathy or myelopathy do occur as well, most commonly when there is mass effect on nerve roots or the spinal cord itself. The mainstay of treatment involves surgical intervention. Curettage has been a surgical option, although marginal excision or wide en bloc resection are preferred options. Adjuvant radiotherapy and chemotherapy are generally not undertaken, although some have advocated their use after less aggressive surgical maneuvers or with residual tumor. In this manuscript, the authors have aimed to systematically review the literature and to put forth an extensive, comprehensive overview of this rare osseous tumor.

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.

Vertebral osteoblastoma: are radiologic structural changes necessary for diagnosis?

BACKGROUND

A case of osteoblastoma localized at the pedicle of the 10th thoracic vertebra 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 thoracic focus of increased osteoblastic activity; however, X-rays, computed tomography, and magnetic resonance images (MRI) were within normal limits, showing only obscure changes that were also noted in the rest of the spine. Repeat MRI with contrast revealed a focal enhancement. After pediculectomy, histopathologic 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 classical radiological appearance. Although non-contrast computed tomography and T1-weighted MRI are mildly positive in some instances, osteoblastoma is best visualized on MRI with gadolinium. Like any other neoplasm, osteoblastoma should be detected and removed early, before it can cause structural bony changes.

Osteoid osteoma and osteoblastoma of the spine. Factors associated with the presence of scoliosis

STUDY DESIGN

A retrospective study of 44 museum cases of spinal osteoid osteoma or osteoblastoma and a meta-analysis using 421 additional cases from a review of the literature.

OBJECTIVES

To identify the factors that are associated with the development of scoliosis in these patients.

SUMMARY OF BACKGROUND DATA

Painful scoliosis is a well recognized presentation of spinal osteoid osteoma and osteoblastoma and is considered to be secondary to pain-provoked muscle spasm on the side of the lesion. Previous studies have been based on small numbers of patients that did not permit statistical validation of the reported observations.

METHODS

Eight factors were assessed including: age, gender, duration of symptoms, site of lesion in the spine, vertebral level of lesion, site of lesion in the individual vertebra, type of lesion, and Cobb angle at presentation. Reports were reviewed only if the presence or absence of scoliosis could be determined. Statistical analyses initially were performed on the museum cases and then on a combination of museum cases and cases from the literature.

RESULTS

Overall, 63% of subjects had scoliosis. The lesions were typically present on the concave aspect of the curve. Three cases of scoliosis from the literature involved lesions that were reported to be on the convexity. Scoliosis is significantly more common in cases of osteoid osteoma than in cases of osteoblastoma (P < 0.0001); lesions are more common in the thoracic and lumbar regions than in the cervical region (P < 0.0001), in lower cervical region than in the upper cervical region (P value = 0.0027), and they are more commonly located to one side of the midline (P < 0.0001). Age, gender, and duration of symptoms were of no significance.

CONCLUSIONS

The findings support the concept that scoliosis is secondary to asymmetric muscle spasm in patients with spinal osteoid osteoma or osteoblastoma.

Benign pediatric bone tumors. Evaluation and treatment

Several recent significant advances have been made in the evaluation and treatment for bone lesions in children. Most advances have come as a result of better imaging of these lesions, namely with magnetic resonance imaging. When a child presents with a bone lesion, several aids allow the treating physician to develop a differential diagnosis. Both recent advance and newer techniques in the diagnosis and treatment of children with benign bone lesions are discussed.