Here is the light microscopic appearance of membranous nephropathy in which the capillary loops are thickened and prominent, but the cellularity is not increased. Membranous GN is the most common cause for nephrotic syndrome in adults. In most cases there is no underlying condition present (idiopathic). However, some cases of membranous GN can be linked to a chronic infectious disease such as hepatitis B, a carcinoma, or SLE.
Characteristic urinalysis findings are shown below.