[A case of hard metal lung disease presenting a type of chronic hypersensitivity pneumonitis].

A 35-year-old man was admitted to our hospital because of abnormal shadows on the chest radiograph and dry cough and exertional dyspnea. He was given a diagnosis of hard metal lung disease 15 years previously and was treated with corticosteroid. Laboratory examination revealed hypoxemia and reduced pulmonary vital capacity. Chest radiograph and high-resolution computed tomography (HRCT) on admission showed ground-glass opacities with volume loss and small cystic spaces. Bronchoalveolar lavage fluid (BALF) demonstrated bizarre multinucleated giant cells and transbronchial lung biopsy (TBLB) specimens showed interstitial pneumonia with multinucleated giant cells. He has worked as a metal grinder, and tungsten was detected in his BALF metal analysis. His illness was diagnosed as hard metal lung disease with giant cell interstitial pneumonia (GIP). We considered this case as a type of chronic hypersensitivity pneumonitis due to his high sensitivity and his disease worsened gradually for four years. Since hard metal lung disease may recur in individuals with high sensitivity, we should always be aware of the possibility of recurrence of this disease.