[Pneumoconiosis diagnosed in a dentist]

A 74-year-old man was admitted to our hospital because of exertional dyspnea in January 2003. He had first noticed slight exertional dypnea in 1997, which had since gradually progressed. He has been a dentist since the age of 23. Chest radiography demonstrated bilateral reticular shadows, infiltrates, and thickened pleural adhesion, which had progressed for one year and five months. Chest CT scans disclosed irregular peribronchial opacities, centrilobular nodules, and interlobular septal lines. Bronchoalveolar lavage fluid showed an increase in total cells and lymphocytosis with an increased CD 4/CD 8 ratio. Transbronchial lung biopsy demonstrated fibrosis around bronchioles, involving adjacent alveolar structures and scattered birefringent particles under polarized light. Energy-dispersive X-ray analysis (EDXA) of the small particles around the bronchioles using electron microscopy showed high peaks for silicon (Si) and aluminium (Al). Pneumoconiosis, possibly induced by some of the mechanical and technical procedures of dentistry, was diagnosed.