Neoadjuvant and Adjuvant Treatment with Denosumab in Aggressive Giant-cell Tumor of Bone in the Proximal Fibula: a Case Report.

Giant cell tumor of bone is a histologically benign but locally aggressive osteolytic lesion, capable of spreading 'benign' metastases mainly to the lungs. Since its description as a separate entity, surgery has been the mainstay of treatment. Recently, target therapy has been introduced using denosumab - an inhibitor antibody for the receptor activator of nuclear factor kappa B ligand with dramatic eff ect on the natural course of the tumor. Herein, we report a rare case of an aggressive stage 3 giant cell tumor of bone of the proximal fibula that was successfully downstaged using neoadjuvant denosumab treatment and then treated by surgical excision followed by adjuvant target therapy. The clinical characteristics and treatment modalities of giant cell tumor of bone, the indications for target therapy, therapy response, and histological changes are also briefly discussed.