高度のチタン沈着を認めた砥の粉による塵肺の1例  [in Japanese] Tonoko Pneumoconiosis with Deposition of Titanium  [in Japanese]

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Abstract

症例は56歳の男性で30年来, 砥の粉を用いた木工家具の塗装作業に従事していた. 50歳頃より労作時呼吸困難を自覚し, 53歳時に当科を初診した. 胸部X線写真では両側肺に大陰影と気腫性変化を認め, 経気管支肺生検にて砥の粉による塵肺と診断された. その後在宅酸素療法を導入されたが, 呼吸不全が進行し死亡した. 剖検肺では, 肺胞の虚脱に伴う高度の気腫性変化が上葉を中心に認められ, セメントが固まったような灰白色の塊状のものが気腔を占拠していた. 大陰影は炭粉沈着を伴った珪肺結節類似の硝子化結節が癒合したものであった. 灰白色の塊状物質はX線微小分析装置走査電顕にてチタン (Ti) が最も高濃度に認められた. 少量のTiでは肺の線維化を惹起し難いとされているが, 大量長期の暴露で線維化病変を形成する可能性があり, 本例では塗料として使われたTiが, 砥の粉による塵肺を重症化させた可能性が考えられた.

A 56-year-old man had worked as a furniture painter and had been exposed to tonoko polishing powder for 30 years. He had complained of dyspnea on exertion for 7 years, and was admitted to our hospital in 1991. A chest X-ray film revealed large opacities and emphysematous changes in both lung fields. Tonoko pneumoconiosis was diagnosed after transbronchial lung biopsy. Home oxygen therapy was given because of progressive hypoxemia, but the patient died of respiratory failure.<br>At autopsy, examination of the lungs showed severe emphysematous changes, and collapse of alveoli. Many gray masses resembling coating cement were seen especially in the upper lobes. Microscopical examination showed that the large opacities were composed of hyaline nodules, similar to silicotic nodules, with anthracosis. Scanning electron microscopy with X-ray microanalysis revealed a high concentration of titanium in the gray mass. A low dose of titanium would not be expeded to induce fibrotic changes in the lung, but a high dose and long-term exposure might have that effect. Titanium contained in paint might have exacerbated tonoko pneumoconiosis in this patient.

Journal

  • The Japanese journal of thoracic diseases

    The Japanese journal of thoracic diseases 34(11), 1234-1238, 1996-11-25

    The Japanese Respiratory Society

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