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 percent of nephrons need to be destroyed before the kidney loses its concentrating ability?
66%
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
what is the process of renal secondary hyperparathyroidism?
hyperphosphataemia causes hypocalcaemia = less calcitriol = PTH stimulated = Ca released from bone etc but just gets bound to phosphate = fibrous osteodystrophy and tissue mineralisation = rubber jaw. nephron calcinosis
What are some causes of glomeruli damage?
immune complexes
thromboemboli
bacterial emboli
viral/bacterial inf
reduced blood flow
amyloid deposition
What are the consequences of glomeruli disease?
Nephrotic syndrome -
PLN
proteinuria
reduced plasma osmotic pressure
oedema
hypercoagubility
hypercholesterolaemia
What is immune mediated glomerulonephritis?
When circulating immune complexes become lodged in the glomeruli or an immune response to Ag trapped in glomeruli already - this causes damage to the BM
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
What is glomerular amyloidosis often assocaited with?
chronic infl disorders, systemic infectious disease, neoplasia
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
What is glomerulosclerosis?
a decrease in the number of functional glomeruli resulting in chronic proteinuria
- get less blood flow through vasa recta as from efferent a and get resulting tubular hypoxia
Describe the histopathic appearance and suggest a cause
loss of capillaries and replacement of mesangial matrix and bowmans space by fibrous CT
-glomerulosclerosis
Which part of the tubule is most vulnerable?
PCT
What is primary renal glycosuria?
Nowegian elkhounds
functional disorder so capacity of tubules to resorb glucose is decreased
What is faconi syndrome?
Basenji dogs
hereditary defect in tubular reabsorption of protein, glucose, phosphate, AA - get progressive renal insufficiency and fibrosis
What is cystinuria?
sex linked tubular defect in male dogs that predisposis to calculus formation and obstruction
What is the most important cause of acute renal failure?
acute tubular necoriss
What is the pathology behind nephrotoxic pigments?
The renal threshold for absorption of Hb and Myoglobin is exceeded so get tubular necrosis secondary to hypovolaemia or severe anaemia
What can cause haemoglobinuric nephrosis?
chronic copper toxicity in sheep
babesiosis in cattle
red mapple toxicity in horses
what can cause myoglobinuric nephrosis?
extensive muscle necrosis and myoglovin release
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 pathogens can cause interstitial nephritis?
e.coli
EVA / PRRS
canine adenovirus
lepto
FIP
What pathogen has caused this?
E.coli
interstitial nephritis
-white spotted kidney
What effect does leptospirosis have on the kidney?
causes tubulointerstitial nephritis
- organisms in interstitial capillaries and migrate into tubular lumen causing degeneration and necrosis.
- Infiltration of macrophages, lymphocytes and plasma cells in the interstitium
What shape infarcts do you get on the kidney?
wedge shaped
what effect does FIP have on the kidney?
- granulomatous necrotising vasculitis and interstitial pyogranulomas
- histopath - oedema, haemorrhage, neutrophil/lymphocytes /plasma cell infiltrate
What is a renal tumour of embryonal origin?
nephroblastoma
What is a renal tumour of mesenchymal origin?
primary renal sarcoma (fibroma, fibrosarcoma, haemangiosarcoma)
what is a renal tumour of epithelial origin?
adenoma
carcinoma
transitional cell papilloma/carcinoma
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
What is the blood supply so the medulla?
from cortex after passing through glomeruli and entering the vasa recta
what are some primary and secondary causes of papillary necrosis?
Primary - NSAID use
secondary - reduced vasa recta blood flow, compression of renal papilla
What are signs of acute cystitis and what commonly causes it?
dysuria
stranguria
haematuria
often bacterial - excess ammonia - damaged mucosa and alkaline urine
What are 3 categoried of chronic cystitis?
Diffuse - thickened mucosa
follicular - nodules on surface
polypoid - masses of proliferative noduled of connective tissue
what causes emphysematous cystits?
secondary to glycosuria
what toxin can cause cystitis?
bracken fern
what mesenchymal tumours can affect the LUT?
leiomyoma
fibroma
lymphoma
rhabdomyosarcoma
