Histopathology: Hypertension and diabetes in the kidney These presentations are to help you identify basic histopathological features. They do not contain the additional factual information that you need to learn about these topics, or necessarily all the images from resource sessions. Before viewing this presentation you are advised to review relevant histology, relevant sections in a pathology textbook, relevant lecture notes, relevant sections of a histopathology atlas and the histopathology power point presentation on vascular pathology. Copyright University of Adelaide 2011 (Med 1: Hypertension semester 1; diabetes semester 2)
With age in the kidney: Hyaline arteriolosclerosis and fibroelastic hyperplasia of small arteries -> narrowing Narrowing -> chronic ischaemia -> atrophy of glomeruli and tubules, and interstitial chronic inflammation and fibrosis. Nephrons are not affected equally. The kidney macroscopically shows variable cortical atrophy with a granular surface, the latter due to alternating atrophic and non-atrophic nephrons. These changes are known as benign nephrosclerosis or arterionephrosclerosis These changes are more severe in hypertension Hyaline arteriolosclerosis also occurs with diabetes mellitus (and some other renal diseases)
Normal glomerulus and tubules. Note that Bowman s capsule (red arrows) is lined by simple squamous epithelium and the tubules by simple cuboidal epithelium (yellow arrows).
Fibroelastic intimal thickening in a small artery.
Tubule Normal arteriole Capillary Hyaline arteriolosclerosis/ arteriolar hyalinosis
Hyalinised arteriole
Atrophic renal tubules with thickened basement membranes (stained deep pink) and fibrosis (black stars) of the interstitial tissue (interstitial fibrosis) in arterionephrosclerosis. PAS stain.
Obsolescent or sclerosed glomeruli (yellow arrows). Chronically injured glomeruli from any cause (e.g. chronic ischaemia, immunological damage) become fibrosed and frequently atrophied. The cells of the glomerular tuft die (becoming acellular) and it atrophies (black star) and scar tissue fills the remainder of Bowman s space (blue star). The associated tubules also atrophy as does ultimately the entire kidney. Red star: normal glomerulus.
Low power view. Normal glomeruli (blue stars), sclerosed/obsolescent glomeruli (yellow stars), atrophic tubules (black stars), interstitial fibrosis and chronic inflammation (red stars).
Atrophic tubules with thickened basement membranes (black arrows). Normal tubules are present in the upper half of the image. Note chronic interstitial inflammation and scarring (yellow stars).
Low power view. Depressed areas of the kidney surface (black arrows) due to atrophy of underlying nephrons. Red arrows: sclerosed glomeruli Yellow arrows: normal glomeruli Yellow stars: areas of tubular atrophy and interstitial chronic inflammation
Small artery in accelerated hypertension. There is concentric thickening of the wall (hyperplastic arteriolosclerosis or "onion skin" endarteritis) and thrombosis of the lumen (black arrow). Fibrinoid necrosis of the wall may also occur. This results in acute glomerular ischaemia, necrosis and acute renal failure.
Accelerated hypertension. Fibrinoid necrosis of arterioles, visible as replacement of the wall by material stained bright red (F), is seen in the wall of a renal arteriole in malignant hypertension. From Stevens et al: Core Pathology 3rd ed. Copyright 2009 by Mosby, an imprint of Elsevier, Ltd.
Diabetic glomerulosclerosis: nodular (yellow stars) and diffuse (black star) areas of thickening of the mesangial matrix. Hyalinised arteriole (black arrow).
Normal Diabetes Diabetes: thickened glomerular capillary basement membranes
Diabetes: capsular drop (arrow)