1. IgG4 Isolated Retroperitoneal Fibrosis and Aneurysmal Periaortitis
Catalina Sanchez-Alvarez, MD, Andrew W. Bowman, MD, PhD, David M. Menke, MD, Benjamin Wang, MD 
The American Journal of Medicine 
Volume 130, Issue 12, Pages e521-e524 (December 2017)
DOI: /j.amjmed
Copyright © 2017 Elsevier Inc. Terms and Conditions

2. Figure 1
Axial contrast-enhanced computed tomography images at the level just above the aortic bifurcation. Arterial phase image (A) demonstrates extensive retroperitoneal soft tissue encircling the abdominal aorta (Ao) by nearly 270° (gray block arrows). Abnormal soft tissue also encases the inferior mesenteric artery (black thin arrow) and an ileocolic branch of the superior mesenteric artery (white thin arrow). Fifteen-minute delayed image (B) demonstrates low-level enhancement in the retroperitoneal soft tissue. Mild inflammatory changes extend laterally to the right from the primary retroperitoneal process (white hatched arrows). The underlying aorta is ectatic with a calcified wall and mural plaque (black arrowheads).
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3. Figure 2
Axial contrast-enhanced magnetic resonance images with gadofosveset at the same level as in Figure 1 performed 1 month after the initial computed tomography (CT) scan. Similar to the earlier CT, portal venous phase image (A) demonstrates extensive retroperitoneal soft tissue encircling the abdominal aorta (gray block arrows). Abnormal soft tissue again encases the inferior mesenteric artery (black thin arrow) and an ileocolic branch of the superior mesenteric artery (white thin arrow). Motion-corrected subtraction image (B) demonstrates clear enhancement in the retroperitoneal soft tissue (white *). More conspicuous than on the prior CT is effacement of the inferior vena cava by the retroperitoneal tissue (gray curved arrow). Stable ectasia of the infrarenal abdominal aorta.
The American Journal of Medicine  , e521-e524DOI: ( /j.amjmed )
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4. Figure 3
Hematoxylin & eosin 100× demonstrating sclerosing lymphoplasmacytic infiltrate (black arrow) with focal storiform fibrosis (white arrow).
The American Journal of Medicine  , e521-e524DOI: ( /j.amjmed )
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5. Figure 4
CD × demonstrating density of plasma cells (CD138); please see Figure 5 to compare.
The American Journal of Medicine  , e521-e524DOI: ( /j.amjmed )
Copyright © 2017 Elsevier Inc. Terms and Conditions

6. Figure 5
400×: Immunostaining for IgG-4 demonstrating >30 cells per high power field. In comparison with CD138 stain, there is evidence of IgG4 deposition in more than 40% of the totality of plasma cells.
The American Journal of Medicine  , e521-e524DOI: ( /j.amjmed )
Copyright © 2017 Elsevier Inc. Terms and Conditions

7. Figure 6
Axial contrast-enhanced, portal venous phase magnetic resonance images with gadofosveset at the same level as in Figures 1 and 2, performed prior to (A) and after treatment (B). (A) is the same image as in Figure 2A. (B) is from a study performed 3 months after the examination shown in (A). There has been marked reduction in retroperitoneal soft tissue post treatment. While the proximal inferior mesenteric artery remains encased (black thin arrow), the ileocolic branch of the superior mesenteric artery is now virtually free of disease (white thin arrow). Decreased mass effect on the IVC. Stable ectasia of the infrarenal abdominal aorta.
The American Journal of Medicine  , e521-e524DOI: ( /j.amjmed )
Copyright © 2017 Elsevier Inc. Terms and Conditions