Electron micrograph showing renal amyloidosis

Electron micrograph showing expansion of the mesangium by amyloid fibrils, which can measure 7 to 12 nanometers in diameter. The fibrillar appearance is best appreciated at the arrow. These fibrils are smaller than those seen in fibrillary and immunotactoid glomerulonephritis.

Electron micrograph of a normal glomerular capillary loop showing the fenestrated endothelial cell (Endo), the glomerular basement membrane (GBM), and the epithelial cells with its interdigitating foot processes (arrow). The GBM is thin, and no electron-dense deposits are present. Two normal platelets are seen in the capillary lumen.