Abstract
A 51 year-old man was admitted to our hospital in December, 1984, because of dyspnea on exertion, dry cough, and left-sided chest pain during the previous 2 months. He had smoked one and a half packs of cigarettes daily since age 16, had no medical problems, and did not take any medication. From 1949, he had been working at Chichibu mine, Saitama, Japan and milling talc for 19 months.
Physical examination revealed fine crackles at bilateral lung bases. His chest roentgenogram showed small irregular opacities with linear shadows, bilateral pleural thickening and left-sided pleural effusion. Thoracentesis yielded blood-tinged fluid with lymphocytes and crystalline substances.
To establish a definite diagnosis, a bronchoalveolar lavage (BAL) and a pleural biopsy were performed. Although evaluation for neoplasm, tuberculosis, and connective tissue diseases were negative, polygonal-shaped materials were demonstrated in both phagolysosomes of alveolar macrophages in BALF and collagen bundles of parietal pleura. A transbronchial lung biopsy showed alveolar wall hypercellularity, interstitial fibrosis and scattered asbestos fibers which were needle-shaped and sometimes more rounded.
Using electron microscopy and X-ray diffraction, the asbestos fibers in BALF, pleura, and lung were revealed to be actinolite (Ca2(MgFe)5Si8O22(OH)2) the mean aspect ratio of which was 50:1 or more, that mineral also was frequently contained in the talc produced from Chichibu mine. Further, the substances in the pleural fluid were not actinolite but halloysite (Al2Si2O2(OH)5·2H2O), the pathogenicity of which has not been reported in the literature.
In this case, the definitive diagnosis of asbestosis induced by the exposure of actinolite and the presumptive diagnosis of benign asbestos pleurisy were made, but the significance of halloysite in the pleural effusion remains uncertain.
