肺に多発した炎症性筋線維芽細胞腫

Multiple Pulmonary Inflammatory Myofibroblastic Tumor

炎症性筋線維芽細胞腫瘍（IMT）は炎症細胞浸潤の著明な腫瘍であり，世界保健機関（WHO）分類では間葉系腫瘍の1亜型として分類されている．その頻度は肺腫瘍全体の0.04％程度と報告1）されており，まれな疾患といえる．われわれは肺に多発した肺IMTの1例を経験したので報告する．

A 67-year-old man visited hospital because of prolonged cough. Chest computed tomography （CT） revealed multiple tumors in bilateral lungs. Transbronchial lung biopsy did not reveal malignancy. Because antibiotic treatment was ineffective, partial resection of the right lung was performed for establishing the diagnosis. The pathological diagnosis was inflammatory myofibroblastic tumor. The postoperative course was uneventful. After 6 months postsurgery, he complained of breathing difficulty and exacerbation of the lesions was found by chest CT. By methylprednisolone pulse therapy, the symptom was improved, and the size of lesions reduced. Since this event, he has been administered oral prednisolone （PSL） 10 mg/day, and the exacerbation of the disease has not been noted.