Fibrillary glomerulonephritis versus immunotactoid glomerulopathy

Electron micrographs showing the 2 different fibrillar patterns in fibrillary glomerulonephritis: true fibrils, which are 2 to 4 times larger than those seen in amyloidosis (left panel), and immunotactoids, which appear as microtubules with a hollow center (right panel).

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.