Pathology Flashcards
granular casts ‘muddy brown’
acute tubular necrosis
casts in urine indicate that the site of haematuria / pyuria is where?
glomerular or tubular in origin
i.e. haematuria due to bladder cancer -> haematuria without casts
fatty casts ‘oval fat bodies’
nephrotic syndrome
associated with Maltese cross sign
waxy casts
end stage renal disease / chronic kidney disease
hyaline casts
non-specific, can be normal function kidney with dehydration, exercise or diuretic therapy
pathophysiology of proteinuria in nephrotic syndrome
podocyte damage -> impaired charge barrier -> poteinuria
granular ‘stary sky’ appearance on immunoflourescence
post-infective glomerulonephritis due to IgG, IgM and C3 deposition along GBM and mesangium
what type of hypersensitivity reaction is post infective glomerulonephritis
type III
what type of hypersensitivity reaction is good pastures syndrome
type II
antibodies associated with microscopic polyangitis and eosinophillic granulomatosis with polyangitis
MPO
pANCA
antibodies associated with granulomatosis with polyangitis
PR3
cANCA
main cause of diffuse proliferative glomerulonephritis
SLE
wire loping of capillaries on light microscopy
diffuse proliferative glomerulonpehritis
features of Alport syndrome
x-linked dominant
type IV collagen mutation
eye problems, glomerulonephritis, SNHL
(cant see, cant pee, cant hear a bee)
basket weave appearance on electron microscopy
Alports syndrome
(baskets at the port)
GMB splitting and ‘tram-track’ on H&E and PAS stains
membrano-proliferative glomerulonephritis
effacement of podocyte foot processes
minimal change disease
focal segmental glomerulosclerosis
spike and dome appearance of subepithelial deposits
membranous nephropathy
eosinophillic casts resembling thyroid tissue
thyroidization of kidney
occurs in chronic pyeloonephritis
causes of acute interstitial nephritis
remember the causes of inflammation to your DRAINS;
D iuretics
Rifampicin
Antibiotics (penicillins, cephalosporins)
I - PPI’s
NSAIDS
Sulpha drugs
symptoms of acute interstitial nephritis
haematuria
fever
rash
pyuria
costovertebral angle tenderness
in the recovery phase of acute tubular necrosis, what electrolyte abnormality are you at risk of
hypokalaemia
features of renal papillary necrosis
sloughing of necrotic renal pappilae = gross haematuria
Associated with;
‘SAD papa with pappilary necrosis’
Sickle cell
Acute pyelonephritis
Analgesics i.e. NSAIDS
Diabetes
mutation in ADPKD
mutation in genes encoding polycystin protein;
PKD1 - chromosome 16
PKD2 - chromosome 4
mutation in autosomal recessive polycystic kidney disease
PKHD1 encoding fibrocytin
condition that may be associated with renal cell carcinoma
Von hippel lindau
mutation associated with clear cell renal carcinoma
gene deletion on chromosome 3
most common subtype of renal cell carcinoma
clear cell
paraneoplastic syndromes associated with renal cell carcinoma
‘PEAR’
PTHrP
Ectopic EPO
ACTH
Renin
polygonal clear cells filled with accumulated lipis and carbohydrates
renal cell carcinoma
large eosinophillic cells with abundant mitochondria without perinuclear clearing
benign renal oncycytoma
mutations associated with Wilm’s tumour (nephroblastoma)
loss of function of tumour suppressor genes WT1 or WT2 on chromosome 11
risk factors associated with urothelial carcinoma of bladder
PEE SAC
Smoking
Aromatic amines (i.e. 2-Naphthylamine)
Cyclophosphamide
risk factors associated with squamous cell carcinoma of the bladder
4 S’s
Schistosomiasis
chronic Systitis (cystitis)
chronic Stones
Smoking
mechanism of diabetic nephropathy
non-enzymatic glycation of tissue proteins -> mesangial expansion, GBM thickening and increased permeability and hyperfiltration
proteinuria
hexagonal crystals on urinalysis
cystinuria
testing modality for cystinuria
cyanide nitroprusside
features of cystinuria
recurrent kidney stones
may have family history - autosomal recessive
genetic mutations on chromsome 2 or 19
hexagonal crystals in urinalysis
cyanide nitroprusside test is positive
proliferation of mesangial cells
IgA nephropathy
recurrent UTI’s with urease-positive bacteria (i.e. proteus mirabilis) can increase risk of kidney stones of what composite ?
ammonium magnesium phosphate (struvite)
what syndrome may Wilm’s tumour be associated with
beckwith-Wiedemann syndrome
WAGR
denys - drash syndrome
renal cell carcinoma (clear cell) arises from which part of the kidney
proximal convoluted tubule
microscopy - congo red stain shows apple green birefringence under polarised light
amyloidosis
extracellular deposition of an insoluble fibrillar protein
amyloidosis
most common causative organism of prostatitis
e.coli (gram negative)
most common composite of renal stone with cystinuria
cystine
most common composite of renal stone
calcium
most common composite of renal stone with gram negative urease bacteria
struvite
most common composite of renal stone with conditions with high cell turnover i.e. cancer
uric acid
what type of renal stones are radio-lucent and therefore may not be visible on xray
cystine stones
uric acid stones
glomerulonephritis caused by igG antibodies and is positive for C3 on microscopy
membrano proliferative glomerulonephritis
persistent activation of alternate complement pathway
- GBM splitting and tram track on PAS stains
urine Na and osmolality if pre renal
Urine Na < 20
Urine osmolality > 500
subepithelial ‘humps’ caused by lumpy immune complex deposits
post strep glomerulonephritis
- granular ‘stary sky’ appearance
what type of glomerulonephritis is associated with HIV
FSGS (focal segmental glomerulosclerosis)
renal failure + proteinuria
linear antibody deposits along the basement membrane on immunoflourescence
anti-GBM disease (good pastures)
renal failure + pulmonary haemorrhage
glomerular injury with normal light microscopy
minimal change
glomerular injury with small vessel haemorrhage
small vessel vasculitis i.e. granulomatosis with polyangitis, microscopic polyangitis, eosinophillic granulomatosis
how does minimal change disease cause increased prothrombotic risk
can cause renal vein thrombosis due to loss of anti thrombin
focal segmental glomerulosclerosis secondary causes
HIV, sickle cell, infection, obesity, congenital malformations
diffuse capillary and GBM thickening
membranous glomerulonephritis
kimmel-steil wilson lesions
diabetic nephropathy
(eosinophillic glomerulosclerosis)
secondary causes of membranous nephropathy
drugs (NSAIDS, penicillamine, gold)
infections (hepatits B and C, syphillis)
SLE
tumours
is fractional excretion of sodium high or low in pre renal AKI ?
< 2% (low) in pre-renal
WAGR features
wilms tumour
aniridia (partial loss of iris)
genital anomalies
range of developmental delays
RENAL TUBULAR MEDHCANISM IN ALKALOSIS CAUSED BY VOMITING
increased Na/H exchange in proximal convoluted tubule
cause of hypernatraemia with urine high urine osmolality and low urinary Na
non-renal water loss i.e. vomiting, burns
loss of heparan sulphate proteoglycans
nephrotic syndrome
Na in serum, urine and urine osmolality found in nephrogenic diabetes insipidous
hypernatraemia, low urine Na, low urine osmolality
how does NSAIDS cause renal damage
afferent arteriolar constriction
defect in amino acid reabsorption in proximal convoluted tubule
cystinuria –> kdiney stones
what type of kidney stones can be caused by a urine infection with urease producing bacteria
struvite stones
intestinal malabsorption of fat can cause what type of stones
calcium oxalate
rapid destruction of blood erythrocytes can cause what type of stones
urate
kidney stones can cause a rise in what urinary substrates
calcium
uric acid
oxalate
electrolyte effects of mannitol
hyponatraemia with high serum osmolality (as mannitol remains in the circulation = high osmolality, it draws water out of cells = hyponatraemia)
what electrolyte abnormality would chlorthiazide cause?
hypercalcaemia (causes excretion of water and chloride and retains calcium)
acetazolamide causes excretion of what substances
sodium chloride and bicarbonate
what UTI causing bacteria produces urease
staph. saprophyticus
what UTI causing bacteria ferments lactose and forms pink colonies on McCockney agar
E.coli
what UTI causing bacteria produces hydrogen sulphide
proteus
salmonella
action of ADH
acts on V2 receptors in the collecting ducts
wilms tumour, nephrotic syndrome, dysgenesis of gonads
denys drash syndrome
(diffuse mesangial sclerosis)
wilms tumour, macroglossia, organomegaly, hemihyperplasia, omphalocele
beckwith-wideman syndrome
chromosome affected in wilms tumour
chromosome 11
how to convert glucose mg/dl to mmol/l
x by 0.0555
hyponatraemia, urine Na low and low urine osmolality
psychogenic polydypsia
pathophysiology of hepatorenal syndrome
vasodilatation of splanchnic arterial vasodilatation causes shunting of blood from the kidneys to the gut
rapid onset of AKI without evidence of renal ischaemia or insult
normal histology of he kidney
no improvement with albumin
Mesangial and subendothelial IgM, C3 l, and k light chains
membrano-proliferative glomerulonephritis
Subepithelial deposition of IgG, C3, and leukocytes
post strep glomerulonephritis
common mets in wilms tumour
lung and liver
does nephrogenic diabetes insipidous respond to vasopressin
no due to ADH resistance (volume depletion leads to elevated ADH levels but this doesnt increase water due to resistance)
complications of polycystic kidney disease
cerebral aneurysms
hepatic cysts
cardiac valvular lesions
UTI with lack of nitrite on urinalysis and by culture on bile esculin agar
enterococcus
UTI with lack of nitrite on urinalysis
gram positive - staph or enterococcus
UTI caused by bacteria with blue green pigment, fruity odour and is drug resistant
pseudomonnas
UTI caused by bacteria which produces urease and causes struvite stones, motility causes swarming on agar
proteus
UTI caused by bacteria that produces red pigment
serratia marcescens
thinning and splittig of glomerular basement membrane
alport syndrome
renal changes in response to haemorrhage
increase renin from juxtaglomerular cells + constriction of afferent and efferent arterioles to retain Na and constrict vessels to increase blood pressure
features of siADH
euvolaemic hyponatraemia
serum osmolality < 275
urine osmolality > 300
urine Na <> 40
reduced free water clearance
first line treatment - water restriction. consider tolvaptan/domeclocycline
antihypertensive that causes metabolic alkalosis with low K
thiazide like diuretics
where does wilms tumour originate from?
metanephric blastema
renal disease, loss of deep tendon reflexes, ECG changes, nausea
low magnesium
what chromosome is affected in ADPKD
chromosome 16
