Figure 3.

Acute kidney lesions. (a) Glomerular and arteriolar thrombotic microangiopathy with acute fibrin thrombi in the arteriolar lumen (arrow) and clear subendothelial spaces with double contours (star). Masson Trichrome, original magnification ×20. (b) Ischemic glomeruli with retracted flocculus in the Bowman space (star) and numerous tubular macrovacuolizations (arrow) in the cortex. Masson Trichrome, original magnification ×5. (c) Crystal (arrow) within the cytoplasm of an epithelial cell of a proximal tubule, HES, original magnification ×20. This crystal is refringent under polarized light. (d) None refringent crystals found in the tubular lumen of proximal tubules (arrows). Masson Trichrome, original magnification ×10. (e) Ischemic glomerulus and numerous tubular microvacuolizations in proximal tubules (arrows) suggestive of acute CNI toxicity. Masson Trichrome, original magnification ×10. (f) Immunohistochemistry with anti SV40 antibody showing several positive nuclei (arrows), in favor of a polyomavirus nephropathy. Original magnification ×40. CNI, calcineurin inhibitors.