The resected specimen of a kidney is seen below. What is the diagnosis?
A. Acute post-streptococcal glomerulonephritis
B. Flea-bitten kidney of malignant hypertension
C. Chronic glomerulonephritis
Ans: B. Flea-bitten kidney of malignant hypertension
(Ref: Robbins 9/e p940)
- The image is typically showing a flea bitten kidney that is a granular kidney with multiple petechial spots. Flea bitten kidney is a descriptive term referring to the petechial hemorrhages and micro infarctions on the renal cortical surface, typical of malignant hypertension, which are caused by thrombosis in the arcuate and interlobular arteries.
- The kidney size varies depending on the duration and severity of the hypertensive disease.
- Small, pinpoint petechial hemorrhages may appear on the cortical surface from rupture of arterioles or glomerular capillaries, giving the kidney a peculiar ‘flea-bitten” appearance.