Radiologic findings of a patient with bronchiolitis interstitial pneumonitis before and after glucocorticoid therapy. (A) Initial chest radiography shows diffuse fine reticulonodular opacities and mixed multiple patchy opacities with peripheral predominance in both lungs. There is also fibrocalcified lesion in left upper lung field which is suggestive of inactive pulmonary TB lesion. (B) Follow-up chest radiography after completion of glucocorticoid therapy shows a marked resolution of diffuse fine reticulonodular opacities and mixed patchy opacities in both lungs. (C) An initial chest HRCT image (lung window setting) at the level of lower hemithorax shows bilateral symmetric multiple patchy areas of peribronchial ground-glass opacities (GGOs), diffuse bronchial and bronchiolar wall thickening, and mixed ill-defined centrilobular nodules in both lungs. (D) A follow-up chest HRCT image (lung window setting) at the same level of image of (C) after completion of glucocorticoid theraphy shows marked improvement of multiple patchy areas of peribronchial GGOs, diffuse bronchial and bronchiolar wall thickening, and mixed ill-defined centrilobular nodules in both lungs.

The pathologic findings of lung specimen resected by video-assisted thoracoscopic surgery. (A) Resected lung specimen shows an architectural alteration of pulmonary alveolar structures and diffuse interstitial thickening (H&E stain, ×40). (B) The bronchiole shows a dilatation of bronchiole, mucostasis, and smooth muscle hyperplasia (H&E stain, ×100). (C) In peribronchiolar portion, mild interstitial thickening and fibrosis are predominantly shown (H&E stain, ×100).