A 50-year-old diabetic woman has microalbuminuria that progresses to nephrotic-range proteinuria over 5 years. Renal biopsy shows nodular glomerulosclerosis. The pathognomonic nodule in diabetic nephropathy is called:
- A Wire-loop lesion
- B Kimmelstiel-Wilson nodule ✓
- C Fibrinoid necrosis nodule
- D Podocyte fusion node
Correct answer: B. Kimmelstiel-Wilson nodule
Explanation
The Kimmelstiel-Wilson nodule is the pathognomonic lesion of diabetic nephropathy on light microscopy — an oval to spherical deposit of laminated matrix material expanding the mesangium in a peripheral lobule of the glomerulus, often with a peripheral cap of compressed capillaries. Wire-loop lesions are seen in lupus nephritis class III/IV due to subendothelial immune deposits. Fibrinoid necrosis is seen in crescentic glomerulonephritis and malignant hypertension.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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