Aneurysmal bone cyst secondary to giant cell tumor of the extremities: a case series of 30 patients.

The purpose was to investigate the clinical features, diagnosis, treatment, and prognosis of aneurysmal bone cyst (ABC) secondary to giant cell tumors (GCT) of the extremities. Data from patients with ABC secondary to GCT of the extremities were obtained from the medical records. Clinical features, imaging findings, pathologic diagnosis, surgical methods, and prognosis were analyzed. The median age of the patients was 33 years (range 15 to 52 years) and 83.3 percent were between 20 to 40 years. The lesions were mainly located in the proximal tibia and distal femur, accounting for 63.3% (19/30). 21 patients were treated with curettage, and 9 with tumor resection. The recurrence rates of the curettage group and resection group were 52.4% and 11.1% respectively. However, the average postoperative (Musculoskeletal Tumor Society) MSTS score were 28.6±1.2 post-curettage, and 25.0±0.5 post-resection, with a significant difference between the 2 groups (P<0.01). In these relapsed patients, 10 underwent a second curettage, while 2 cases underwent a resection and there was no postoperative re-recurrence in both groups. A comprehensive analysis should be performed when making the diagnosis of ABC secondary to GCT. Although the recurrence rate is higher, curettage is still the optimal method for satisfactory joint function. If recurrence occurs after the first curettage, a second curettage should be performed.