Diseases of the Renal system 2 Flashcards
What is obstructive uropathy?
obstruction of the urinary tract
anywhere from the renal pelvis to the urethral meatus
chronic or acute
unilateral or bilateral
What are the causes of urinary tract obstruction in the pelvis?
calculi/stones
tumours
ureteropelivic strictures - above becomes distended
What are the causes of urinary tract obstruction in the ureter-intrinsic?
calculi tumours clots sloughed papillae inflammation
What are the causes of urinary tract obstruction in the ureter-extrinsic?
pregnancy
tumours
reteroperitoneal fibrosis
What are the causes of urinary tract obstruction in the bladder?
calculi
tumours
functional
What are the causes of urinary tract obstruction in the urethra?
posterior valve stricture
tumours (rare)
What are the causes of urinary tract obstruction in the prostate?
hyperplasia
carcinoma
prostatitis
What is the consequence of obstructions of the urinary tract?
infections e.g. cystitis, pyelonephritis
stones/calculi formation
kidney damage - acute/chronic
What can obstruction at the urethral level cause to the detrusor muscle?
hypertrophy and trabeculation
due to bladder contracting hard
What is the name of the condition in which the ureter is dilated?
hyroureter
What is hydronephrosis?
dilated calyces
dilated pelvis
cortical atrophy - thin cortex
What can complete acute obstruction cause to the kidney?
Reduction in glomerular filtration rate
Mild dilatation and mild cortical atrophy
can lead to acute renal failure
What can chronic and intermittent obstruction cause to the kidney?
Filtrate passes back into interstitium → Compression of medulla
Impaired concentrating ability → Eventual cortical atrophy, fall in renal filtration and renal failure
OR
Continued glomerular filtration → Dilatation of pelvis+calyces → Eventual cortical atrophy, fall in renal filtration and renal failure
What are the clinical features of acute bilateral obstruction?
pain
acute renal failure
anuria - no urine
What are the clinical features of chronic unilateral obstruction?
Asymptomatic initially
unresolved = cortical atrophy and reduced renal function
What are the clinical features of bilateral partial obstruction?
polyuric
progressive renal scarring and impairment
How does Renal calculi/Urolithiasis form?
excess substance precipitates out e.g. Ca2+
change in urine constituents causing precipitation i.e. change in pH
poor urine output
decreased citrate levels
How are Renal calculi/Urolithiasis classified?
by composition
e.g. Calcium stones (70%) - calcium oxalate +/- calcium phosphate
Struvite stones (15%) – magnesium ammonium phosphate
Urate stones (5%) – uric acid
Cystine stones (1%)
What are the main causes of calcium stones?
hypercaliuria due to: hypercalcaemia - Bone disease, PTH excess, sarcoidosis excessive absorption of intestinal Ca+ inability to reabsorb Ca+ idiopathic
How does struvite stones produce staghorn calculi?
urease converts urea to ammonia → rise in urine pH → precipitation of magnesium ammonium phosphate salts → staghorn calculi
What are the main causes of urate stones?
hyperuriceamia - gout, patients with high cell turnover e.g. leukaemia
idiopathic
What are the main causes of cystine stones?
rare
inability for kidney to reabsorb amino acids
What investigations are undertaken when suspecting renal calculi?
Non-contrast CT scanning = gold standard
Ultrasound in pregnancy or where CT not possible
Intravenous urography
What can renal calculis lead to?
obstruction
haematuria
infection
squamous metaplasia +/- squamous cell carcinoma
What are majority of renal cell carcinomas?
clear cell
What are the risk factors for renal cell carcinoma?
Tobacco Obesity Hypertension Oestrogens Acquired cystic kidney disease (due to chronic renal failure Asbestos exposure
What is Von Hippel-Lindae Syndrome?
most common cancer syndrome in renal call carcinoma
VHL gene affected - controls the breakdown of hypoxia inducible factor 1 oncogene
loss of gene causes cell growth and survival
common in clear cell renal cell carcinoma
tumours in kidneys, blood vessels, pancreas
What is the presentation of Von Hippel-Lindae Syndrome?
haematuria palpable abdominal mass costovertebral pain systemic symptoms metastases (later) Paraneoplastic syndromes
What are Paraneoplastic syndromes?
Clinical syndromes caused by tumours e.g. Cushings
Not related to the tissue that the tumour arose from but what it secretes
Not related to invasion by the tumour itself or its metastases
What paraneoplastic syndromes are associated with renal cell carcinomas?
Cushing’s syndrome - produced ACTH
Hypercalcaemia - parathyroid hormone related peptide
Polycythaemia - Erythropoietin
What is the morphology of clear cell renal cell carcinoma?
well defined yellow tumours
haemorrhagic areas
may extend into perinephric fat/renal vein
Where is Urothelial cell Carcinoma located?
Most common in the bladder but may arise anywhere in renal parachyme
arise from specialised multilayer epithelium
What are the risk factors for urothelial cell carcinomas?
age
gender - more common in males
carcinogens e.g. smoking, radiotherapy
What are the signs and symptoms of urothelial cell carcinomas?
HAEMATURIA - most common
urinary frequency
pain on urination
urinary tract obstruction
Which histological patterns of transitional cell carcinoma are non invasive?
papilloma-papillary carcinoma
flat non invasive carcinoma
Which histological patterns of transitional cell carcinoma are invasive?
invasive papillary carcinoma
flat invasive carcinoma
