Light micrograph showing membranous nephropathy

Light micrograph of membranous nephropathy, showing diffuse thickening of the glomerular basement membrane (long arrows) with essentially normal cellularity. Note how the thickness of the glomerular capillary walls is much greater than that of the adjacent tubular basement membranes (short arrow). There are also areas of mesangial expansion (asterisks). Immunofluorescence microscopy (showing granular IgG deposition) and electron microscopy (showing subepithelial deposits) are generally required to confirm the diagnosis.

Light micrograph of a normal glomerulus. There are only one or two cells per capillary tuft, the capillary lumens are open, the thickness of the glomerular capillary wall (long arrow) is similar to that of the tubular basement membranes (short arrow), and the mesangial cells and mesangial matrix are located in the central or stalk regions of the tuft (arrows).