A 24-year-old male presents to your office with a complaint of progressive dull, aching pain in his neck. Recently, he has developed sharp pain that radiates from his neck down his arm. He denies history of trauma. He denies fever or chills. X-rays of the spine are within normal limits. MR and CT are performed (Fig. 8–13).

Figure 8–13

All of the following are characteristics of this lesion except:

1. Located in posterior elements of the spine

2. Can cause a painful scoliosis

3. Marked bone expansion can be seen

4. Large soft-tissue mass can impinge on exiting nerve roots

Discussion

The correct answer is (D). Osteoblastoma is a benign but locally aggressive osteoid-producing tumor. It is most common in the spine, especially the posterior elements. It is typically larger than 2 cm in diameter and on CT scan, can have central mineralization and marked bone expansion. This can cause spinal cord and nerve root impingement, as well as a painful scoliosis. Soft-tissue mass accompanying this bone-forming lesion is not typically seen.

The patient asks about surgical intervention versus nonoperative management. Is surgery indicated for this lesion, and why or why not?

1. Yes, because it has relatively high rate of malignant transformation

2. Yes, because this is an aggressive lesion that is not self-limiting

3. No, because pain is well controlled with aspirin and it is a self-limiting process that resolves spontaneously in approximately 3 years

4. No, because the lesion rarely if ever causes pain, or fracture and does not undergo malignant transformation

Discussion

The correct answer is (B). Unlike osteoid osteomas, osteoblastomas are not self-limiting and are actually quite locally aggressive. Especially in the spine, they usually cause symptoms of pain and sometimes a neurologic deficit. Treatment is curettage or marginal excision. They do not possess the potential for malignant transformation, therefore choice A is incorrect. Choice C describes a strategy for medically managing osteoid osteomas, which is not effective management of osteoblastomas.

The patient agrees to surgery. The most appropriate treatment for his osteoblastoma in the posterior elements of his spine is:

1. Wide resection alone

2. Wide resection with postoperative radiation therapy

3. Intralesional curettage with bone grafting or cementation

4. Neoadjuvant chemotherapy, then curettage and adjuvant therapy with phenol

Discussion

The correct answer is (C). Given the tumor has a predilection for the spine, the lesion is frequently found in a difficult anatomic location, often making surgery challenging. Curettage of osteoblastoma with bone grafting, or sometimes cementation, is the first-line surgical treatment. There is no role for systemic chemotherapy or radiation in first-line treatment. Wide resection is usually not necessary except in cases of recurrence, which can occur in 10% to 20% of cases.

Objectives: Did you learn...?

To recognize clinical and imaging features of osteoblastoma? How to manage osteoblastoma?

The differences between osteoid osteoma and osteoblastoma?