Giant-cell tumor of bone (GCTB) is a rare osteolytic tumor of the bone. Although classified as a benign tumor, GCTB is characterized by local aggressiveness and risk of local recurrence. Its name is derived from the numerous multinucleated giant cells found within the tumor, which are principally responsible for the extensive bone resorption that is characteristic of GCTB. However, the neoplastic components of GCTB are the spindle-like stromal cells, which produce RANKL that recruits monocytic osteoclast precursors from blood to the tumor, and stimulates differentiation into multinucleated giant cells. Recently, denosumab (RANKL inhibitor) has become a new treatment option for locally advanced GCTB.
