May 18, 2017
Renal parenchyma with florid interstitial fibrosis with thick bands of sclerosis expanding the interstitium and pushing the tubules apart on the Jones methenamine silver stain at (100X). Examination at 400X on the H&E stain reveals a dense mixed interstitial inflammatory infiltrate that is rich in plasma cells. These findings are characteristic of renal involvement by a systemic fibroinflammatory disease known as IgG4-related disease. IgG4 staining of the tissue confirmed the presence of numerous IgG4-positive plasma cells.