[Giant cell interstitial pneumonia in a metal grinder with an abnormally high level of serum CA19-9].

Interstitial pneumonia and recurrent pneumothorax developed in a 48-year-old man who had worked as a metal grinder. He died of respiratory failure despite having received antibiotics and steroids, and despite having undergone pleural sclerosis therapy. Giant cell interstitial pneumonia was diagnosed; innumerable bizarre giant cells engulfing black granules were found within the alveoli. The results of high-energy dispersion X-ray microanalysis indicated that the patient had hard metal pneumoconiosis associated with tungsten in the black granules. When he was admitted to the hospital, his serum CA19-9 and SLEX concentrations were abnormally high (2600 and 200 ng/ml, respectively). Immunohistochemical analysis of lung tissue was done with anti-CA19-9 and SLEX antibodies. CA19-9 staining revealed strong bronchialization and squamous metaplasia in contrast to type II hyperplasia. SLEX staining showed strong type II hyperplasia. Further investigations will be needed to determine the mechanism of elevated tumor-associated carbohydrate antigens in serum.