56-year-old male suffered from renovascular hypertension; nephrectomy was performed.
- A section of the kidney is shown. In the lower part of the slide, the cortex shows a regular architecture; individual glomeruli are set apart by a vast number of tubules exhibiting distinct lumens.
- In the upper part of the slide, the surface of the kidney is conspicuously depressed. In this region, glomeruli are crowded due to pronounced tubular atrophy. The tubules are small and often have inapparent lumens, thus forming in part solid sheets of epithelium. This pattern is typical of chronic ischemic atrophy. It is also referred to as ‘endocrinization’ of tubules, because of the resemblance of atrophic tubules to the acinar tissue of endocrine glands.
- A modest interstitial infiltrate of mononuclear cells is present, however, fibrosis is absent.
Nomenclature: Chronic ischemic atrophy has also been referred to as subinfarction. Hypoxemia is severe enough to cause atrophy in subinfarction.
Pathogenesis: Ischemia of the entire kidney or a segment of the kidney due to stenosis of the main renal artery. This is most commonly caused by atherosclerotic occlusion. Fibromuscular dysplasia (renal artery stenosis in children and young adults), vasculitis (e.g.Takayasu’s arteritis), retroperitoneal fibrosis, neurofibromatosis and compression of the artery by a neoplasm are observed infrequently. Consequence of renal artery stenosis is a decrease in renal arteriolar pressure leading to an increased secretion of renin by juxtaglomerular cells and in turn production of the vasoconstrictor angiotensin II.