Pathology.—NSIP is characterized by a histologic pattern of uniform interstitial involvement by varying degrees of chronic inflammation or fibrosis. NSIP may be idiopathic or seen in other settings, including collagen vascular disease, hypersensitivity pneumonitis, drug-induced lung disease, infection, and immunodeficiency (including human immunodeficiency virus infection) (5).
CT scans.—NSIP has variable thin-section CT appearances: The most frequent is ground-glass opacities with reticulation, traction bronchiectasis or bronchiolectasis, and little or no honeycombing (Fig 43). The distribution is usually basal and subpleural (95). [Fleischner Society]