Hypertensive nephrosclerosis: benign vs malignant
- Lesion
Long-standing hypertension glazes small renal arteries and slowly shrinks the kidneys; very high pressure tears them open.
What it is
This page covers the kidney view of hypertensive vascular disease. In benign nephrosclerosis, chronic moderate hypertension causes hyaline arteriolosclerosis and fibroelastic thickening of small arteries, with ischemic loss of nephrons and symmetric, finely granular contracted kidneys. In malignant hypertension, pressure rises abruptly or very high and injures endothelium, producing fibrinoid necrosis and onion-skin hyperplastic arteriolosclerosis, a thrombotic microangiopathy with rapid kidney failure.
Structure
- Benign: kidneys slightly small; cortex thin; surface finely and evenly granular.
- Arterioles show homogeneous pink hyaline walls; interlobular arteries show medial hypertrophy and reduplicated elastic lamina.
- Patchy ischemic atrophy: tubular atrophy, interstitial fibrosis and globally sclerosed glomeruli.
- Malignant: pinpoint petechial hemorrhages on the surface; fibrinoid necrosis, concentric layered smooth muscle (onion skin), necrotizing glomerulitis.
Benign vs malignant nephrosclerosis
| Pattern | Vessel lesion | Gross kidney | Course |
|---|---|---|---|
| Benign nephrosclerosis | Hyaline arteriolosclerosis, fibroelastic hyperplasia | Small, symmetric, finely granular | Slow loss of GFR, mild proteinuria |
| Malignant hypertension | Fibrinoid necrosis, hyperplastic (onion-skin) arteriolosclerosis | Petechiae: flea-bitten surface | Rapid kidney failure, retinopathy, encephalopathy |
Clinical notes
- Hypertension is the second cause of chronic kidney disease after diabetes, and kidney damage itself raises blood pressure.
- Malignant hypertension needs emergency lowering of pressure; high renin from ischemic kidneys perpetuates the cycle.
Test yourself
Think of the answer, then tap the question to see it.
What is the vascular lesion of benign nephrosclerosis?
Hyaline arteriolosclerosis: homogeneous pink thickening of arteriolar walls by leaked plasma proteins and matrix.
Why is the kidney flea-bitten in malignant hypertension?
Ruptured, necrotic arterioles and glomerular capillaries cause pinpoint hemorrhages on the cortical surface.
What does onion-skinning mean?
Concentric layers of smooth muscle and basement membrane in the arteriolar wall: hyperplastic arteriolosclerosis.
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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Chronic Kidney Disease (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.