On electron microscopy of a renal biopsy, 'subepithelial humps' (electron-dense deposits under podocyte foot processes) are the hallmark of which nephritis?

• A Membranous nephropathy
• B Post-streptococcal acute proliferative glomerulonephritis ✓
• C Lupus nephritis class IV
• D C3 glomerulopathy

Explanation

Post-streptococcal GN classically shows large, 'humpy' subepithelial electron-dense deposits on EM, representing immune complexes (IgG, C3) deposited between the GBM and podocytes after group A streptococcal pharyngitis or impetigo. The 'hump' morphology is pathognomonic. Membranous nephropathy also has subepithelial deposits but they are diffuse, spike-like, and smaller without the hump morphology. Lupus nephritis class IV shows subendothelial, mesangial, and occasional subepithelial deposits. C3 glomerulopathy features predominant C3 deposits without significant immunoglobulin.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.