What is the typical electron microscopy finding in minimal change disease?

• A. Foot process effacement of podocytes with preserved overall glomerular architecture
• B. Subepithelial immune complex deposits
• C. Mesangial proliferation
• D. Basement membrane splitting

Answer: (A)

Minimal change disease produces nephrotic syndrome with normal light microscopy and negative immunofluorescence, so the key EM finding is diffuse effacement of podocyte foot processes across the glomerulus while the glomerular basement membrane and overall architecture remain intact. This widespread foot process effacement disrupts the slit diaphragm, allowing large amounts of protein to leak into the urine, which explains the prominent proteinuria. The lack of immune deposits on EM helps distinguish it from immune complex–mediated diseases; subepithelial deposits would suggest membranous nephropathy, mesangial proliferation points to mesangial GN, and basement membrane splitting is seen in MPGN.