[Hard metal lung with diffuse small nodular shadows].

A 32-year-old woman was admitted to Niigata University Hospital with dyspnea and a non-productive cough. She had been exposed to hard metal dust for 4 years in a metal-polishing factory. Chest X-ray and CT films showed diffuse small nodular shadows in both lung fields and pulmonary-function tests revealed severe restrictive impairment. Specimens obtained by thoracoscopic lung biopsy showed fibrosis in the centers of lobules and in peribronchiolar regions. Giant-cell interstitial pneumonia-like findings were also noted. Tungsten carbide and cobalt were detected in these specimens, with an X-ray microanalyzer. Hard metal lung was diagnosed. By 1 year after she changed her place of work and began corticosteroid treatment her symptoms and pulmonary function had improved remarkably, although shadows on chest X-ray films remained to some extent.