Figure legends :
Figure 1 : Mesangial fibrosis with mesangiolysis and reduction of the lumen of glomerular capillaries (Trichrome stainingx40).
Figure 2 : Segmental fibrinoid necrosis in a glomerulus (Trichrome stainingx40).
Figure 3 : Onion bulb appearance in medium-caliber vessels (Trichrome stainingx40)