[Pronounced progression of interstitial pneumonia in a precious metal worker]

A 43-year-old man who had been engaged in the precious-metal processing industry for 18 years was admitted to our hospital because of shortness of breath on exertion. Chest roentgenograms disclosed ground glass opacities and annular-nodular shadows in the basal area of the right lung field and almost all of the left lung field. A video-assisted thoracoscopic lung biopsy was performed, and histologic examination disclosed usual interstitial pneumonia (UIP). Mineral analysis revealed high modes of silicon and aluminum, two elements consistent with the materials used in the patient's factory. The histopathological findings indicated interstitial pneumonia caused by the inhalation of dust particles. After corticosteroid therapy, computed tomographic scans disclosed that the ground glass opacities had subsided, but that honeycomb shadows remained. A chest roentgenogram taken 2 years earlier demonstrated only minute granular lesions in the basal area of right lung field. The interstitial shadows had progressed significantly over the intervening 2-year span. The findings in this case should be of value to the etiologic study of UIP.