Keishi Sugino, Hirotaka Ono, Mikako Saito, Miho Kobayashi, Seiji Igarashi, Akira Hebisawa
A 56-year-old man with a family history of interstitial lung disease and long-term occupational exposure to toxins as a dental technician presented with progressive dyspnea. High-resolution computed tomography revealed a usual interstitial pneumonia pattern (UIP). A surgical lung biopsy revealed UIP with fibroblastic foci and granulomatous lesions containing birefringent particles. An elemental analysis identified multiple inorganic elements, including silica and dental metals, but not cobalt or tungsten. Despite antifibrotic and anti-inflammatory therapy, the disease progressed rapidly, and the patient died while awaiting lung transplantation. These findings suggest that mixed-dust exposure may accelerate fibrosis in genetically susceptible patients with familial interstitial pneumonia.