微小病变性肾小球肾炎，特点是：脏层上皮细胞（足细胞）的足突消失，正常的离子屏障丧失，表现为选择性白蛋白漏出，接着出现蛋白尿。光镜下，微小病变的肾小球是正常的。在这张电镜照片的下半部的毛细血管袢中有2个高电子密度的RBC。可见有窗孔的内皮细胞及正常的基底膜。然而，脏层上皮细胞(足细胞)表面的足突消失或融合。
This is minimal change disease (MCD) which is characterized by effacement of the epithelial cell (podocyte) foot processes and loss of the normal charge barrier such that albumin selectively leaks out and proteinuria ensues. By light microscopy, the glomerulus is normal with MCD. In this electron micrograph, the capillary loop in the lower half contains two electron dense RBC's. Fenestrated endothelium is present, and the basement membrane is normal. However, overlying epithelial cell foot processes are effaced (giving the appearance of fusion) and run together.
