Review Question - QID 4471

The clinical presentation and imaging studies are consistent with and aneurysmal bone cyst (ABC). Curettage and bone grafting is the most appropriate treatment.

Aneurysmal bone cysts are a benign and non-neoplastic reactive bone lesions filled with multiple blood-filled cavities. They can be locally destructive to normal bone and may extend to soft tissue. 75% occur in patients who are < 20 years old. In the presence of a pathologic fracture, treatment is nonoperative fracture management. In the absence of a pathologic fracture, treatment is curettage and bone grafting.

Gibbs et al. reviewed 40 patients treated for ABC. Of these patients, 34 were treated with curretage and bone grafting. Only 4 of these patients had local recurrence. Recurrence was found to be associated with younger patients and open physes.

Ramirez et al. found that in 29 patients, the most common location of an ABC was within the tibia. They found a 27.5% recurrence rate after treatment with curretage, curretage & bone grafting, or resection. Use of a high speed metal burr help reduce the local recurrence.

Figures A-E demonstrate radiographic, MRI and histologic findings of an ABC. In figure A, note the involvement of the metaphyseal bone of the ilium and bony septae that give it a bubbly appearance. In Figure B, note the fluid-fluid lines seen on the T2-weighted MRI. Figure C reflects the low signal nature of an ABC on T1; note the eccentric lytic destructive pattern. Figure E demonstrates the large blood-filled, cavernous spaces associated with ABC lesions that lack an endothelial lining.

Incorrect Answers:
Answer 2: Phenol injections are often used as adjuvants to extend the curretage for management of giant cell tumors. Phenol is not used alone
Answer 3,4: Observation/radiofrequency ablation can be utilized in the management of osteoid osteomas.
Answer 5: Wide resection/adjuvant chemotherapy can be used to treat osteosarcoma.