Giant Aggressive Aneurismal Bone Cyst of the Proximal Humerus Unresponsive to Denosumab

Aneurysmal Bone Cyst (ABC) is a destructive lesion. The main treatment is curettage, local adjuvant and grafting. However, it is difficult to apply the optimal surgical procedure in aggressive lesions. In these cases, the use of denosumab prior to surgery has been shown to reduce bone destruction and facilitate surgical treatment. A 22-year-old woman was referred for limited shoulder movement and pain complaints. Physical examination and radiological findings were interpreted in favor of ABC. The biopsy was also found to be consistent with the ABC. Since the lesion was aggressive, denosumab was applied prior to surgery. The mass quickly became calcified and patient’s pain complaint decreased. After stopping denosumab treatment, lesion progressed rapidly and destructive character became dominant at every part of lesion. The patient underwent proximal humeral resection and prosthesis. A painless limb with limited shoulder movement was achieved. Although denosumab application prior to surgery was initially good in this case, after termination of treatment, lesion progressed rapidly and the gains associated with denosumab use was lost.