Fig. 4

A Peri-glomerular and peri-vascular inflammation, degeneration and necrosis of the tubular epithelial lining. Some tubules contain red blood cell casts. B Distorted glomerular structure. Fibrin deposition in the capillary loops (fibrin thrombi) obliterating the capillary lumina, accompained by karyorrhectic debris in the glomerular tuft. Segmental breaks of the glomerular basal membrane (GBM and disruption of Bowman's capsular membrane are also visible. Renal parenchyma showing severe inflammatory response around an affected glomerulus. C Jones methenamine silver (JMS) stain shows an affected glomerulus with crescent formation consisting of proliferated parietal epithelial cells and fibrin between them. The crescent, obliterating Bowman's space and compressing the glomerular capillary tuft, is focally adherent to Bowman's membrane. A rupture of Bowman's capsular basal membrane is also visible. D An affected glomerulus showing large congestion with fibrin thrombi in the capillary loops and fibrin deposition in Bowman's space. Damage of the GBM and rupture of Bowman's capsule can also be noted