右下腿に発生したMazabraud症候群の1例

Mazabraud Syndrome of the Right Leg. Case Report

　65歳の女性で肺癌の治療中に，右下に発生した腫瘤をきっかけに右腓骨の骨病変が明らかになり，Mazabraud症候群と診断した症例を報告する．軟部腫瘤は生検により筋肉内粘液腫，骨病変は画像所見上で線維性骨異形成と診断された．単骨型線維性骨異形成の悪性転化率は0.5％とされているが，Mazabraud症候群の線維性骨異形成は悪性転化率が8.3％と高く，注意深い経過観察が必要である．

　We report the case of a 65-year-old woman with Mazabraud syndrome.　The patient presented with a mass in the right leg during treatment for lung cancer, and radiography revealed an osseous lesion of her right fibula.　The mass was diagnosed as an intramuscular myxoma by histological examination of an open biopsy specimen, and the osseous lesion was diagnosed as fibrous dysplasia based on the X-ray findings.　Sarcomatous change, has been reported to occur in only 0.5% of patients with solitary fibrous dysplasia, whereas malignant change has been reported to occur in as high as 8.3% of patients with Mazabraud syndrome.　Consequently, patients with Mazabraud syndrome should be closely followed-up for evidence of malignant transformation.