title: A Case Report of IgG4-Related Disease Clinically Mimicking Pleural Mesothelioma.
abstract: An immunoglobulin G4 (IgG4)-related disease is a recently emerging entity, and a few cases of IgG4-related disease in lung and pleura have been reported. Herein, we report the case of a 74-year-old man with IgG4-related disease of lung and pleura, clinically suspicious of malignant mesothelioma. Chest computed tomography showed diffuse nodular pleural thickening, and microscopic finding disclosed diffuse thickening of visceral pleura with infiltrations of many lymphoplasma cells with increased number of IgG4-positive plasma cells and a few multinucleated giant cells. It is important for pathologists and clinicians to recognize this rare entity and its histologic finding, because it can be confused with malignant tumors on the radiologic examination although it can be treated with steroid therapy.
authors: Department of Pathology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: In Ho
authors: IH
authors: Choi
authors: Department of Pathology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Si-Hyong
authors: SH
authors: Jang
authors: Department of Pathology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Seungeun
authors: S
authors: Lee
authors: Department of Pathology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Joungho
authors: J
authors: Han
authors: Department of Radiology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Tae-Sung
authors: TS
authors: Kim
authors: Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Man-Pyo
authors: MP
authors: Chung
keywords: Immunoglobulin G; Lung Diseases; Plasma Cells; Pleural Diseases