title: A Case of IgG4-Related Lung Disease Presenting as Interstitial Lung Disease.
abstract: Intrathoracic involvement of immunoglobulin G4 (IgG4)-related disease has recently been reported. However, a subset of the disease presenting as interstitial lung disease is rare. Here, we report a case of a 35-year-old man with IgG4-related lung disease with manifestations similar to those of interstitial lung disease. Chest computed tomography showed diffuse ground glass opacities and rapidly progressive pleural and subpleural fibrosis in both upper lobes. Histological findings showed diffuse interstitial lymphoplasmacytic infiltration with an increased number of IgG4-positive plasma cells. Serum levels of IgG and IgG4 were also increased. The patient was diagnosed with IgG4-related lung disease, treated with anti-inflammatory agents, and showed improvement. Lung involvement of IgG4-related disease can present as interstitial lung disease and, therefore, should be differentiated when evaluating interstitial lung disease.
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Jee Hwan
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Sun In
authors.initials: SI
authors.lastname: Hong
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Dong Hui
authors.initials: DH
authors.lastname: Cho
authors.affiliation: Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Chae
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Joon Seon
authors.initials: JS
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Song
keywords: IgG4; Lung Diseases; Lung Diseases, Interstitial