骨巨細胞瘤

Giant Cell Tumor of Bone

骨巨細胞瘤（giant cell tumors of the bone）是常見的良性腫瘤之一，具有局部侵襲性以及肺部轉移的能力。雖然很少致命，但骨巨細胞瘤好發生於關節周遭、破壞骨骼結構而造成棘手的情況。其確切的病生理機轉尚未完全明暸，其前驅細胞形成多核蝕骨細胞，影響了骨形成與再吸收之間的平衡，因而成為治療的標的。手術切除是最通用的治療標準，依據腫瘤的大小以及侵犯關節的嚴重程度，從破壞較小的病灶內刮除乃至廣泛性切除皆為手術的選項，切除後的各種輔助療法，以及骨重建方式為手術中重要的挑戰。手術治療的目標為乾淨的腫瘤邊緣（tumor- free margin）、最小化的併發症以及可接受的功能預後。雖然骨巨細胞瘤被分類為良性腫瘤，仍有1-6%的案例會發生遠端肺轉移，具有較差的預後。化療以及放射線治療對於特定的情況（不適合乎術或病灶位置特殊如薦椎等）仍有一定的角色。雙磷酸鹽藉由促使骨巨細胞的凋亡，可作為有效的輔助治療。近期對於RANK-RANKL路徑的了解，發展出單株抗體（denosumab）在骨巨細胞瘤的使用。

Giant cell tumors of bone (GCTB) is generally a benign tumor commonly affecting the bones of knee with potential aggressive behavior and lung metastasis. Although rarely lethal, GCTB may be associated with a substantial disturbance of the local bony architecture that can be particularly troublesome in peri-articular locations. Its pathophysiology remains unclear. It is characterized by the multinucleated giant cells that are the hallmark of the lesion, easily recognized on histological review, which recently have become therapeutic targets for medical management of the disease. GCTB has been treated surgically traditionally. Depending on the involvement of the articular surface, varying surgical techniques ranging from intra-lesional curettage to wide resection has been the primary treatment of giant cell tumor of bone. The surgical goal includes tumor-free margin, minimal morbidity and acceptable functional outcome. Although GCTB is classified as a benign lesion, lung metastases have been reported in 1%-6% cases and potentially worsened the prognosis. Chemotherapy and radiotherapy are reserved for limited cases. Recently, the understanding of involvement of the RANK/RANKL pathway led to the use of denosumab.