好酸球性胸水を呈したGM-CSF，G-CSF産生性悪性胸膜中皮腫の1例

摘要

背景．悪性胸膜中皮腫は比較的稀な腫瘍であり，画像所見，胸水所見からの診断は困難なことが多い．好酸球性胸水を呈したgranulocyte-macrophage colony-stimulating factor（GM-CSF），granulocyte colony-stimulating factor（G-CSF）産生性悪性胸膜中皮腫の1例を報告する．症例．65歳，男性，2002年7月29日右胸背部痛のため当院入院となった．胸水，血液検査，胸部CT所見より好酸球性胸水（胸膜炎）と考えられ，ステロイド内服による診断的治療が施行されたが症状の進行を認めたため，9月17日胸腔鏡下胸膜生検を施行し，悪性胸膜中皮腫（二相型）と診断した．また，経過を通じて白血球，好酸球増多を認め，血清G-CSFは50pg/dlと高値であり，抗GM-CSF抗体，抗G-CSF抗体による免疫染色では腫瘍細胞のほとhどの細胞質と約5％の細胞質にそれぞれ陽性像を認めたことよりGM-CSFおよびG-CSF産生性腫瘍と診断した．腫瘍の進行，全身状態の悪化を認め，11月27日在院死となった．剖検で悪性胸膜中皮腫の壁側臓側胸膜，心外膜，横隔膜，腹膜，小腸，大腸への進展を認めた．結論．炎症反応陽性，治療抵抗性難治性胸水を認めた場合，悪性胸膜中皮腫も疑い早期に胸腔鏡下生検で確定診断を行うことが必要であると考えられた．Background. Malignant pleural mesothelioma (MPM) is relatively rare. This disease was diagnosed with difficulty by pleural fluid analysis and radiographic findings. The following is a report on a case of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) -producing MPM accompanied by eosinophilic pleural fluid. Case. A 65-year-old man was admitted with right chest and back pain on July 29, 2002. The eosinophil count in the pleural fluid and the findings of computed tomography (CT) suggested eosinophilic pleurisy. Despite steroid therapy, his symptoms rapidly worsened. The white blood cell (WBC) count elevated to 28260/mm3 and the G-CSF level of the serum elevated at 50pg/dl. A pleural biopsy under video-assisted thoracoscopic surgery (VATS) was performed on September 17, 2002. Histopathologically, the tumor cells consisted of tubular and nest structures from atypical epithelial cells and spindle-shaped cells. The biphasic type of MPM was diagnosed by the pathological findings. The cytoplasms of almost all tumor cells were immunohistochemically stained with anti-GM-CSF monoclonal antibody.