15 April 2022
: Case report 
A 61-Year-Old Woman Presenting with Low Back Pain Diagnosed with IgG4-Related Disease Affecting the Thoracoabdominal Aorta and Retroperitoneum
Challenging differential diagnosis, Rare disease, Educational Purpose (only if useful for a systematic review or synthesis)
Mi Ra Kim ABCDEF 1, Hyekyung Shim ABCDEF 2*DOI: 10.12659/AJCR.935007
Am J Case Rep 2022; 23:e935007
Figure 2 Representative images of histopathologic and immunohistochemical (IHC) studies of the biopsy specimen from the retroperitoneal fibrotic lesion at diagnosis(A, B) Microscopically, there is dense lymphoplasmacytic infiltration with diffuse marked fibrosis and phlebitis (hematoxylin and eosin staining; ×200 (A) and ×400 (B)). (C, D) On the IHC study images, IgG-positive cells (C) and IgG4-positive cells (D) are observed (200× magnification).