Review Question - QID 7534

The clinical presentation is consistent with an osteoid osteoma, which would benefit most from radiofrequency ablation (RFA) at this time.

Osteoid osteomas are benign but painful lesions with pain that is often worse at night and responsive to NSAIDs. Therefore, treatment focuses on management of symptoms, beginning with NSAIDs. In ~50% of patients, the lesions "burn out" and become asymptomatic over time, though this can take several years. CT-guided RFA is an important treatment option whereby a probe is placed into the lesion and the nidus is heated. This may not be appropriate for lesions adjacent to critical structures (such as spinal cord or neurovascular bundles), and in such instances surgical intervention may be appropriate.

Rosenthal et al. reviewed a consecutive series of 87 patients with osteoid osteoma managed with operative intervention and 38 patients treated with radio frequency ablation. They found no difference in recurrence rates between the two groups, and concluded that percutaneous treatment is preferred for the treatment of extra spinal osteoid osteoma because it generally does not necessitate hospitalization, has not been associated with complications, and is associated with a rapid convalescence.

Figure A is a lateral radiograph showing a bone-forming lesion of the tibial diaphysis, and a corresponding axial CT image showing an osteoid osteoma with central nidus (long white arrow). This classic radiographic appearance, together with clinical history of pain responsive to NSAIDs are classic for osteoid osteoma.

Incorrect Answers:
Answer 1: Given that this patient continues to have daily pain interfering with normal activities despite NSAID use, RFA is a better option than observation.
Answer 2 and 5: RFA is preferred over more invasive measures at this time.
Answer 4: The imaging and history are diagnostic of osteoid osteoma, and as such biopsy would not be necessary.