pathology Flashcards
What condition are these kidneys affected by?
Hydronephrosis
What is the pathogenesis of hydronephrosis?
- obstruction of urine outflow causes high pressure and compression of the delicate tissues in the renal pelvis
- the interstitial BVs collapse and renal blood flow is decreased so get hypoxia and ischaemic necrosis
- the tubules undergo degeneration and are resplaced by interstital fibrosis (the radiating columns)
What can cause hydronephrosis?
urine outflow obstruction by:
- intraluminal occlusion by calculi, mucus plugs, blood clots, neoplasms, infl cells
- external compression by neoplasia, infl, fibrosis, uterine/vaginal prolapse
- congenital anomalies
- trauma
- bladder paralysis
What does this gross image deomonstrate?
indistinct pale striations in innner cortex representing tubular degeneration and necrosis
(ethylene glycol toxicity)
What can be seen on these low and high power microscope images?
multifocal tubular dilation
degenerate tubular epithelial cells distended with intracytoplasmic vacuoles
many tubules contain crystalline material
(ethylene glycol toxicity)
What common substance produced intratubular crystals?
antifreeze containing ethylene glycol
What is the pathogenesis of ingesting ethylene glycol?
- ingested and absorbed from the gut
- oxidised by the liver to toxic metabolites including glycolic acid and oxalate
- there are filtered by the glomeruli and directly cause acute tubular necrosis
- the percipitation of calcium oxalate crystals in the tubule lumen causes intrarenal obstruction and mechanical damage
this is a cow kidney - describe the gross appearance and what is the condition?
Grossly - renal calyces containing suppurative exudate bordered by red rim of haemorrhage
-pyelonephritis
What signs may a cow with pyelonpehritis have?
reduced yield
haematuria
hunched back and painful gait
pain on rectal
pyrexia
What can predispose a cow to pyelonephritis?
- trauma during parturition compromising the defence mechanisms of the ureters
- stress of parturition / peak lactation
- high protein diet causing alkaline pH which is conductive to bacterial colonisation
What pathogens are commonly associated with pyelonephritis in cattle?
Most - e.coli, arcanobacterium pyogenese, corynebacterium renale
opportunes - staph and strep
Describe the microsopic appearance of a and b and what are these conditions called?
A - diffuse degeneration and necrosis of ep cells of convoluted tubules
B - more extensive loss of tubular architecture with indistinct BM
They have acute tubular necrosis (without reactive infl or scar tissue)
What insults can cause acute tubular necrosis?
ischaemia
nephrotoxins
inflammation
infectious agents
How well do kidneys heal after acute tubular necrosis and what affects the repair?
- retained basement membranes are necessary for repair of necrotic tubules as a scaffold for cellular regeneration
- the kidney would heal with fibrous tissues and contract causing a reduction in function in B
- in A would repair by proliferation and function may be maintained
what type of insults commonly retain and destroy tubular basement membranes?
Toxic insults - retain basement membrane
Ischaemic insults - lost basement membrane
Describe the gross appearance? What is the prcoess occuring?
- capsular surface is irregular with multifocal pitting from fibrosis
- small cysts at the corticomedullary junction from where fibrous CT compresses tubules causing dilation proximal to the obstruction
chronic renal failure
What are some lesions associated with uraemia?
ulcerative stomatitis/gastritis/colitis
mineralisation of gastric mucosa / intercostal parietal pleura and pulmonary parenchyma
uraemic pneumonitis
fibrous osteodystrophy
parathyroid hyperplasia
non-regenerative anaemia
Describe the gross appearance of the pancreatic islets? What is the gross appearance of the bladder? What could be causing these?
Pancreatic islets - vacuolated consistent with hydropic degeneration (sustained stimulation from peripheral insulin resistance)
Bladder - multifocal to coalescing raised reddened nodules respresenting cystitis and mucosal emphysema. (Glycosuria enhances bacterial growth and some bacteria split glucose molecules releasing CO2 into the bladder lumen and therefore absorbed into the lymphatics)
(type 2 DM)
describe the gross appearance of this bladder
focally thickened with a discrete raised nodular mass
associated hyperaemia
multifocal suppurative exudate
(transitional cell carcinoma)
what can be seen in this microscopic image?
- atypical epithelial cells forming haphazard islands and nests indicating a neoplasm
- anisokaryosis and anisocytosis with prominent nucleoli consistent with a malignant neoplasm
(transitional cell carcinoma)
what could a large transitional cell carcinoma cause?
occlude urine outflow
urine retention
cystitis
hydroureter
hydronephrosis
pyelitis
pyelonephritis
Describe the gross appearance of this kidney and what is the name given to these lesions?
multifocal irregular pale areas on the capsule bordered by a red rim
renal infarcts
What is the pathogenesis of renal infarcts?
- embolic in the vasculature occlude the interlobar/arcuate/interlobular arteries obstructing the blood supply
- as the kidney has an end arterial supply the area occluded undergoes coagulative necrosis
Describe the gross appearance of these specimens and what is the condition called?
- multifocal pale white/red necrotic foci randomly scattered throughout the capsular and cortical surface
- microsabscesses on glomeruli
- suppurative glomerulitis
what pathogens can cause microabscessation in foals,pigs and small ruminants?
foals - actinobacillus equuli
pigs - erysipelothrix rhusiopathiae
small ruminant - corynebacterium pseudotuberculosis
What is the pathogenesis of suppurative glomerulitis?
- bacteria enter the kidney via the vasculature and lodge in the glomeruli capillaries where they replicate and induced necrosis and inflammation
- forming microabscesses
What percent of nephrons need to be destroyed to get azotaemia?
75%
What is the pathology affecting this kidney?
Chronic renal failure
-pale, undulating capsule, fibrous
What process is going on in this image?
Chronic renal failure
- fibrosis replacing normal anatomy
- atrophic / hyperplastic / hypertrophic tubules
- intraluminal protein
- thickened BM
- calcification of BV and BM
- cysts
- glomerulosclerosis
Describe the gross and histopathic appearance of this image. What is the cause?
Gross - glomeruli visibe as dots on cortex surface
Histopath - increase cellularity and proliferation of glomerular cells, thickening of glomerular BM, deposition of fibrinous thrombi in capillaries, dilated tubulaes wiht protinaceous fluid, fibrosis, glomerulosclerosis
Describe the gross appearance and suggest what could be causing it
Gross - enlarged, pale, glistening dots of amyloid laden glomeruli
glomerular amyloidosis
Describe the histopathic appearance and suggest an underlying cause
Histopath - amyloid in mesangium and subendothelium,
acellular eosinophilic fibrillar material, tubules dilated with proteinaceous and cellular casts
-amyloid appears apple green under polarised light
Describe the histopathic appearance and suggest a cause
loss of capillaries and replacement of mesangial matrix and bowmans space by fibrous CT
-glomerulosclerosis
What bacterial disease is affecting this kidney? What are the consequences?
Clostridium perfingens = pulpy kidney
- acute tubular degeneration +/- necrosis, interstitial oedema and haemorrhage
- reduced GFR and arteriolar vasoconstriction and prolonged ischaemia
What pathogen has caused this?
E.coli
interstitial nephritis
-white spotted kidney
What is the pathological process going on here?
papillary (medullary crest) necrosis
- coagulative necrosis of inner medulla
- can slough and get fragment in pelvis and obstruct ureter
- rarely leads to progressive damage
