These presentations are to help you identify basic histopathologicalfeatures. They do not contain the additional factual information thatyou need to learn about these topics, or necessarily all the images

from resource sessions.Before viewing this presentation you are advised to review relevanthistology, relevant sections in a pathology textbook, relevant lecture

notes, relevant sections of a histopathology atlas and thehistopathology power point presentation on vascular pathology.

Copyright University of Adelaide 2011(Med 1: Hypertension semester 1; diabetes semester 2)

Histopathology:Hypertension and diabetes in the

kidney

With age in the kidney:

• Hyaline arteriolosclerosis and fibroelastic hyperplasia of small arteries

-> narrowing

• Narrowing -> chronic ischaemia -> atrophy of glomeruli and tubules, andinterstitial chronic inflammation and fibrosis. Nephrons are not affected equally.

• The kidney macroscopically shows variable cortical atrophy with a granularsurface, the latter due to alternating atrophic and non-atrophic nephrons. Thesechanges are known as benign nephrosclerosis or arterionephrosclerosis

• These changes are more severe in hypertension

• Hyaline arteriolosclerosis also occurs with diabetes mellitus (and some otherrenal diseases)

Normal glomerulus and tubules. Note that Bowman’s capsule (red arrows) is lined by simple squamous epithelium andthe tubules by simple cuboidal epithelium (yellow arrows).

Fibroelastic intimal thickening in a small artery.

Hyaline arteriolosclerosis/arteriolar hyalinosis

Normal arterioleTubule

Capillary

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. chronicischaemia, 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). Theassociated 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 (blackstars), interstitial fibrosis and chronic inflammation (red stars).

Atrophic tubules with thickened basement membranes (black arrows). Normal tubules are present in theupper 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 glomeruliYellow arrows: normal glomeruliYellow 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 andacute renal failure.

Accelerated hypertension. Fibrinoid necrosis of arterioles, visible as replacement of the wall by materialstained 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 ofthickening of the mesangial matrix. Hyalinised arteriole (black arrow).

Diabetes: thickenedglomerular capillarybasement membranes

Normal

Diabetes

Diabetes: capsular drop (arrow)