[Structural changes in the lung in the late stage of fatal paraquat poisoning].

Poisoning with Paraquat, an efficient weedkiller, causes a progressive interstitial fibrosis of the lung starting after about one week's latency. The X-ray findings of a 30-year-old female patient who died 12 days after oral ingestion of Paraquat could be documented. We found a correlation between X-ray examination and microscopic post mortem findings of necrotizing alveolitis of the lung changing from exsudative to sclerosing alterations. This diffuse interstitial fibrosis was accompanied by an increase of contractile filament laden cells, characterized by an expression of alpha-smooth muscle actin, which could be identified by immunohistochemical methods. The substantial increase in alpha-actin containing cells has recently been observed in cases of Bleomycin-injured lungs.