Conclusions Electron microscopic obser vations show that the alveolar epithelial cells, endothelial cells and basement m结论电镜观察可见特发性肺纤维化时肺泡上皮细胞、血管内皮细胞及基底膜均有损伤，并可见间质巨噬细胞增生，肥大细胞浸润及脱颗粒，肺泡壁电子致密物沉积。