A 40-year-old woman with nephrotic syndrome has serum albumin 1.8 g/dL, 24-hour urine protein 9 g, and normal renal function. Kidney biopsy shows diffuse glomerular basement membrane thickening with a 'spike and dome' pattern on silver stain and granular IgG and C3 deposits on immunofluorescence in a subepithelial distribution. The MOST likely diagnosis is:

• A Focal segmental glomerulosclerosis (FSGS)
• B Membranous nephropathy ✓
• C Minimal change disease
• D Membranoproliferative GN (MPGN)

Explanation

Membranous nephropathy is characterized by diffuse GBM thickening, 'spike and dome' pattern on silver stain (GBM projections between subepithelial deposits), and granular IgG and C3 deposits on immunofluorescence. Anti-PLA2R antibody is positive in 70–80% of primary cases. FSGS shows focal segmental sclerosis. MCD shows fusion of foot processes without GBM changes. MPGN shows GBM splitting ('tram-track') due to mesangial interposition.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.