[A case of pulmonary alveolar proteinosis associated with fibrotic changes and alveolitis]

A 62-year-old male, who had worked for 20 years as a farmer and who had been exposed to respirable agricultural chemicals apart from silica, was admitted in April, 1987, because of progressed exertional dyspnea. The chest X-ray film on admission showed irregularly-distributed infiltrative shadows in both lung fields. The chest CT also revealed irregular increase of densities in lung fields. Though the TBLB specimen from right B8 indicated only fibrotic changes, the tissues obtained by open lung biopsy from right S3 and S8 revealed PAS-positive proteinaceous deposits in the alveoli as well as alveolitis or fibrotic change of alveolar septum. Bronchoalveolar lavage fluid (BALF) contained phospholipids composed mainly of lecithin. According to these findings, the case was diagnosed as pulmonary alveolar proteinosis associated with alveolitis and patchy fibrotic changes. It is not completely clear whether fibrotic changes are induced by pulmonary alveolar proteinosis itself or fibrosis and proteinosis result coincidentally from direct response to fibrogenic agents. Inhaled agricultural chemicals may play a role for the pathogenesis of this case, for which further studies are required.