Fig. 1

Light microscopic findings with periodic acid–Schiff staining (a) revealed diffuse and global endothelial cytoplasm expansion accompanied by focal duplication of the glomerular basement membrane. Spike formation was not evident on the periodic acid-methenamine-silver stained section (b). Electron microscopy revealed swelling of the endothelial cells (c, arrow) and effacement of the podocyte foot process (d). In addition, randomly arranged fibrils (10–20 nm, arrows) are observed in the mesangial, subepithelial and subendothelial regions (d and e). Original magnification a:× 400, b:× 400, c:× 1000, d:× 5000, e:× 15000