Clinical History:
- A 44-year-old African-American man has a history of hypertension, but on arrival in the emergency room his blood pressure is recorded as 220/150 mg Hg.
- What is the nature of the process seen in the renal artery shown here microscopically at high magnification?
This is a hyperplastic arteriolosclerosis in which there is lumenal narrowing with prominent intimal proliferation ("onion-skinning"). This lesion is most likely to accompany malignant hypertension. Malignant hypertension, which complicates about 1% of cases of hypertension, is more common in men.
- What complications are likely to develop?
He could develop renal failure, cerebral hemorrhage (stroke), or congestive heart failure.
- Describe two mechanisms by which renal artery ischemia produces hypertension.
Renal ischemia triggers the release of renin from the juxtaglomerular apparatus. Renin is converted ultimately to angiotensin II which has a direct vasoconstrictor effect as well as a stimulatory effect on the release of aldosterone. The combined salt and water retention triggered by aldosterone and the vasoconstriction lead to renal hypertension. This was originally described by Goldblatt and is often referred to as "Goldblatt hypertension."
Clinical History:
- A 57-year-old woman is developing renal failure. Her BUN is currently 45 mg/dl and her creatinine 3.5 mg/dl.
- Describe the changes seen in this high magnification microscopic image of a renal glomerulus.
The glomerulus demonstrates an area of amorphous deposition of PAS-positive material typical for nodular glomerulosclerosis (Kimmelstiel-Wilson lesion) and the arteriole at the base of the glomerulus shows extensive thickening consistent with hyaline arteriolosclerosis.
- What underlying disease process is probably present?
These changes are typical for diabetes mellitus.
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