Figure 3d. Lymphoid interstitial pneumonia in a 51-year-old woman. (a) Prone high-resolution CT scan obtained through the carina demonstrates peripheral ground-glass attenuation and interlobular septal thickening (arrows). (b) Prone high-resolution CT scan obtained through the lung bases shows bilateral subpleural ground-glass (black arrows) and denser nodular attenuation. There is a minor degree of nodular interlobular septal thickening (white arrow). (c) Photomicrograph (original magnification, x25; hematoxylin-eosin stain) shows alveolar septa that are widened by a lymphoid infiltrate (a). No scarring is present. (d) Photomicrograph (original magnification, x100; hematoxylin-eosin stain) demonstrates interstitial infiltrate that consists of mature lymphocytes (b), plasma cells (c), and macrophages (d). Epithelium lining of the bronchiole (e) is unremarkable.