IgG4-Related Kidney Disease: Report of a Case Presenting as a Renal Mass

Figure 3

Histological findings. (a) Histological section of kidney parenchyma showing a chronic pyelonephritis characterized by the presence of interstitial fibrosis, inflammatory infiltrate of lymphocytes and plasma cells, and atrophy and dilatation of tubules that contain pink casts (hematoxylin-eosin (H-E), 10x). (b) The fibroadipose tissue of the kidney capsule typically shows the histological findings of IgG4-related disease, characterized by an irregularly whorled pattern of fibrosis (storiform fibrosis) associated with inflammatory infiltrate (H-E, 10x). (c) A vein obliterated by a transmural inflammatory cell infiltration (obliterative phlebitis) (H-E, 20x). (d) Immunostaining with anti-IgG4 antibody shows the presence of numerous positive cells (×20).

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