自家骨移植による再建を行った第1中手骨軟骨肉腫の1例

Chondrosarcoma Arising from The First Metacarpal Bone Treated Using Limb Salvage Surgery. Case Report

　76歳の男性の左第1中手骨に発生した軟骨肉腫に対して腫瘍広範切除術後に腸骨からの自家骨移植を用いた患肢再建を行った．摘出腫瘍はgrade 2の軟骨肉腫であったが，手術後22カ月経過し局所再発や遠隔転移なく良好に経過している．再建した母指の機能も良好である．手足発生の軟骨肉腫は稀であるが，生命予後は良好であることが多い．広範切除や患肢機能の再建が困難なことから切断術が選択されることが多いが，第1中手骨の場合は母指機能の重要性を考えるとできるだけ患肢温存療法を行ったほうがよいと考える．

　We recently experienced a rare case of chondrosarcoma arising from the first metacarpal bone that was treated using a wide resection followed by an autogenous iliac bone graft and arthrodesis of the CM and MP joints. The patient was a 76-year-old man who had first experienced pain and swelling around the MP joint of the thumb six months earlier. X-ray and computed tomography examinations revealed massive bone destruction and abnormal calcification of the first metacarpal bone, suggesting chondrosarcoma. After a wide resection of the tumor, the metacarpal bone was reconstructed using an iliac bone graft and arthrodesis of the MP and CM joints. Histological examination of the resected tumor showed a gradeⅡchondrosarcoma with high cellularity and mitosis. No local recurrence or metastasis has occured for 22months since the surgery. Thumb function was well preserved, and the patient can drive a car. We believe that limb salvage surgery may be applicable to patients with chondrosarcoma arising from the first metacarpal bone.