Pathological changes seen in kidney in

Pathological changes seen in kidney in:

  1. Malignant hypertension:
  2. Benign hypertension:

2.Flea bitten kidney

Flea bitten in malignant

Hyaline changes in benign

Hyperplastic arteriosclerosis is seen in malignant hypertension leading to a characteristic “onion peel appearance” on microscopy.


  • Gross: leather-grain kidney

  • Microscopic: Hyaline arteriosclerosis.


  • Gross: Flea bitten kidney

  • Microscopic: Hyperplastic arteriosclerosis; fibrinoid necrosis and onion skinning pattern of smooth muscles.

Flea bitten kidney also in

  • Wegeners

  • HUS

  • HSP

  • PSGN

  • PAN

  • SABE

  • SLE.

Both malignant hypertension and long-standing benign hypertension can show pathological changes in the kidney.

Benign nephrosclerosis shows shrunken kidneys. There can be microscopic subcapsular scars with sclerotic glomeruli and tubular dropout, alternating with better preserved parenchyma. The arterioles and small arteries show hyaline arteriosclerosis.

Malignant nephrosclerosis shows features similar to TMA (thrombotic microangiopathy). The kidney may show patchy or diffuse cortical necrosis and subcapsular petechiae. The glomerular capillaries are distended and occluded by thrombi. The glomeruli are mildly hypercellular and have marked thickening of the capillary walls associated with splitting or reduplication of the basement membrane (double contours or tram tracks).The walls of arteries and arterioles often exhibit increased layers of cells and connective tissue (onion-skinning) that narrow the vessel lumens.

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