A 28-year-old man presents with nephrotic syndrome (proteinuria 8 g/day, albumin 2.1 g/dL). Renal biopsy reveals segmental sclerosis with collapse of glomerular tufts, visceral epithelial cell hypertrophy, and protein resorption droplets. Electron microscopy shows diffuse podocyte foot process effacement. What is the most likely diagnosis?
- A Minimal change disease
- B Membranous nephropathy
- C Collapsing variant of focal segmental glomerulosclerosis (FSGS) ✓
- D IgA nephropathy
Explanation
Collapsing FSGS is characterised by segmental collapse of glomerular capillary tufts with overlying podocyte hypertrophy and prominent protein resorption droplets, distinguishing it from tip-variant FSGS. It carries the worst prognosis among FSGS subtypes and is associated with HIV infection, parvovirus B19, COVID-19 (APOL1 risk variants in persons of African ancestry), and certain drugs. Minimal change disease shows diffuse effacement without structural glomerular change on LM. Membranous nephropathy has subepithelial deposits. IgA nephropathy is nephritic/mixed pattern.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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