1. Immunoglobulin G4–Related Periaortitis Involving the Aortic Arch Mimicking a Mediastinal Tumor 
Min Jae Cha, MD, Semin Chong, MD, Yang Soo Kim, MD, Byungjoon Park, MD, Ja Hee Seo, MD, Eun Sung Lee, MD 
The Annals of Thoracic Surgery 
Volume 103, Issue 3, Pages e267-e270 (March 2017)
DOI: /j.athoracsur
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
(A, B) Axial contrast-enhanced computed tomographic scans demonstrate homogenously enhancing mass–like lesion surrounding the aortic arch and great neck vessels. (C) Coronal and (D) sagittal views also demonstrate a relatively well-circumscribed mass eccentrically involving the aortic arch and neck vessels. (E) Axial and (F) sagittal fluorodeoxyglucose (FDG) positron emission tomography–computed tomography scans show an intensely increased FDG uptake of the mass, with a maximum standardized uptake value of 9.0.
The Annals of Thoracic Surgery  , e267-e270DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
(A, B) Hematoxylin and eosin staining demonstrates lymphoplasmacytic infiltration with fibrosis (A, ×100; B, ×400). (C) Immunohistochemical staining for immunoglobulin (Ig) G and (D) IgG4 demonstrate numerous plasma cells positive for IgG4. The ratio of IgG4 to total IgG was approximately 30%.
The Annals of Thoracic Surgery  , e267-e270DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
(A) Axial and (B) coronal contrast-enhanced CT scans obtained after 2 weeks of corticosteroid treatment demonstrate a diminished mass–like aortic wall thickening.
The Annals of Thoracic Surgery  , e267-e270DOI: ( /j.athoracsur )
Copyright © 2017 The Society of Thoracic Surgeons Terms and Conditions