[A case of respiratory bronchiolitis-associated interstitial lung disease]

We report the first case of respiratory bronchiolitis-associated interstitial lung disease in Japan. A 48-year-old man with a 36-pack-year smoking history was referred because of 6 months of dry cough. Chest X-ray showed bilateral reticulonodular shadows. HRCT scan showed bilateral reticulonodular and ground glass shadows with centrilobular distribution. BAL yielded 85 x 10(6) cells with 99.5% macrophages. Histologic examination of the biopsy specimen obtained under thoracoscopy showed evidence of respiratory bronchiolitis, with accumulation of pigmented macrophages within respiratory bronchioles and adjacent air spaces associated with mild thickening of the peribronchiolar interstitium.