Pulmonary Diffuse Alveolar Septal Amyloidosis

Picture 1. Chest X-ray showing bilateral small nodules. Picture 2. High-resolution computed tomography of the chest, showing interlobular septal thickening and random distribution of small nodules with calcification. Picture 3. Histopathologic findings of the transbronchial biopsy specimens from the right lung: (a) Alveolar septa were thickened with acellular eosinophilc homogeneous materials (arrows) (Hematoxylin and Eosin staining, original magnification 200). (b) Multifocal thickening of alveolar septa with Congo red positive materials were observed (arrows). Congo red positive materials also deposited in the bronchiolar wall and adjacent alveolar region (Congo red stain, original magnification 200). (c) The amyloid materials were covered on both sides with keratin-positive alveolar lining epithelial cells. Thus, amyloid depositions were confirmed in the alveolar septa in these places (arrows) (AE1/AE3 immunostain, original magnification 200).