Vertebral Aneurysmal Bone Cyst Mimicking Osteosarcoma: Case Report and Review of the Literature

Aneurysmal bone cysts are benign osseous lesions containing blood-filled cavities separated by walls of connective tissue. They can be difficult to identify clinically due to similarities in presentation, imaging, and histology with other pathologies. Specifically, it is important to distinguish these benign lesions from malignant processes, as both surgical and medical management differ. We present the case of a 21-year-old patient who presented with impaired motor and sensory function in his lower extremities. Radiologic findings were concerning for an invasive neoplasm, and the intraoperative frozen section supported this conclusion. However, an additional histological investigation was confirmatory for a diagnosis of an aneurysmal bone cyst. The patient underwent corpectomy, laminectomy, and a posterior spinal fusion, and regained motor and sensory function shortly thereafter. This report details the importance of considering aneurysmal bone cysts in the differential of infiltrative bone lesions, despite their benign nature, as medical and surgical management can vary greatly.

Treatment of osteoid osteoma of the elbow by radiofrequency thermal ablation

BACKGROUND

This article presents the experience at the Rizzoli Orthopaedic Institute in the treatment of intracapsular osteoid osteoma (OO) of the elbow by computed tomography-guided percutaneous radiofrequency thermal ablation (RFA).

MATERIALS AND METHODS

Our team performed more than 800 RFA procedures to treat OO up to 2010. In 27 cases, the lesion site was the articular area of the elbow (humerus in 13 cases, ulna in 13, and radius in 1). These patients were reviewed and assessed for eradication rate, incidence of complications, and functional results measured by the Mayo Elbow Performance Score. The outcome was evaluated after a mean follow-up period of 67.4 ± 35.3 months (range, 24-128 months).

RESULTS

The mean duration of symptoms at the time of diagnosis was 31.0 ± 19.8 months (range, 5-72 months). All patients complained about pain, and in 24 of 27 cases (88.8%), the joint function was significantly impaired by the presence of OO (pretreatment score, 54.8). After RFA, the Mayo Elbow Performance Score improved by a mean of 37.7 ± 14.8 points, with 25 of 27 patients (92.5%) scoring 90 to 100 points at final follow-up. OO recurred in only 1 patient (3.7%), 5 months after the procedure. However, this was successfully retreated by RFA. No adverse effects were observed, and all patients were free of disease at the final follow-up.

DISCUSSION

The RFA procedure can be technically challenging in difficult sites such as the elbow joint. The low invasiveness of RFA compared with traditional surgery allows excellent functional recovery. RFA of elbow OO is effective and safe, and it should be considered the first-choice treatment for this disease.