Renal System 2 Flashcards
What is obstructive uropathy?
- Obstruction of urinary tract
- Anywhere from renal pelvis to urethral meatus
- Chronic or acute
- Unilateral or bilateral
What are causes of urinary tract obstruction in the kidney pelvis?
- Calculi
- Tumours
- Ureteropelvic stricture
What are intrinsic causes of urinary tract obstruction in the ureter?
- Tumours
- Calculi
- Clots
- Sloughed papillae
- Inflammation
What are extrinsic causes of urinary tract obstruction in the ureter?
- Pregnancy
- Tumours (cervix)
- Retroperitoneal fibrosis
What are causes of urinary tract obstruction in the prostate?
- Hyperplasia
- Carcinoma
- Prostatitis
What are causes of urinary tract obstruction in the bladder?
- Calculi
- Tumours
- Severe reflux
- Neurological conditions
What can acute complete obstruction lead to?
- Reduction in gloerular filtration rate
- Mild dilatation & mild cortical atrophy
- Can cause acute renal failure
What can partial or intermittent obstruction lead to?
1) Filtrate passes back into interstitium
2a) Compression of medulla
2b) Continued glomerular filtration
3a) Impaired concentrating ability
3b) Dilatation of pelvis & calyces
4) Eventual cortical atrophy, fall in renal filtration& renal failure
What are the clinical features of urinary tract obstruction?
- Pain
- Acute renal failure & anuria
- Bilateral partial obstruction= polyuric with progressive renal scarring & impairment
What are the pathogenesis of urinary tract obstruction?
- Excess of substances which may precipitate out (Ca+)
- Change in urine constituents causing precipitation of substances (change in pH)
- Poor urine output (supersaturation)
- Decreased citrate levels
What is the classification of urinary tract obstruction? (types of stones)
- Calcium stones
- Struvite stones
- Urate stones
- Cystine stones
- Different stones for different reasons
What causes calcium stones?
-Hypercalciuria due to:
Hypercalcaemia (bone disease, PTH excess, sarcoidosis)
Excessive absorption of intestinal Ca+
Inability to reabsorb tubular Ca+
Idiopathic
-Gout (forms a core Ca+ crystal formation)
-Hyperoxaluria (excess dietary intake, heredetary)
How are struvite stones formed?
1) Urease producing bacterial infection converts urea to ammonia
2) Causes a rise in urine pH
3) Precipitation of magnesium ammonium phosphate salts
4) Large staghorn calculi
How are urate stones formed?
- Hyperuricaemia (Gout, high cell turnover-leukaemia)
- Idiopathic
How are cystine stones formed?
- Rare
- Occur in presence of inability of kidneys to reabsorb amino acids
What can urinary tract obstruction lead to?
- Haematuria
- Infection
- Suamous metaplasia +/- squamous cell carcinoma
What are risk factors for renal cell carcinoma?
- Tobacco
- Obesity
- Hypertension
- Oestrogen
- Acquired cystic kidney disease (due to chronic renal failure)
- Asbestos exposure
What is Von Hippel-Lindau Syndrome?
- Most common of several cancer syndromes
- Gene required for breakdown of hypoxia inducible factor-1 oncogene
- Loss of gene function causes cell growth & inc cell survival
- Tumours develop in kidneys, blood vessels, pancreas
- VHL mutations commonly identified in clear cell RCC
What is the presentation of renal cell carcinoma?
- Haematuria
- Palpable abdominal mass
- Costovertebral pain
- Late presentation: systemic symptoms or metastases
What are paraneoplastic syndromes?
- Syndromes caused by tumours
- Not related to the tissue that the tumour arose from
- Not related to invasion by tumour itself/metastases
Name some paraneoplastic syndromes associated with renal cell carcinoma
- Cushing’s syndrome (ACTH)
- Hypercalcaemia (parathyroid hormone related peptide)
- Polycythaemia (erythropoietin)
Describe the morphology of renal cell carcinoma
- Clear cell
- Well defined yellow tumours
- Often with hemorrhagic areas
- May extend into perinephric fat or renal vein
- Papillary= more cystic, more likely to be multiple
Describe a renal cell carcinoma microscopically
-Delicate vasculature
-Small bland nuclei
-Papillary tumours:
Cubiodal, foamy cells
-Surrounding fibrovascular cores often containing foamy macrophages or calcium
What is urothelial cell carcinoma/transitional cell carcinoma?
- 90% of all bladder Ca
- Bladder tumours
- Arising from specialised multilayered epithelium
- May arise anywhere from renal pelvis to urethra
What are the risk factors for urothelial cell carcinoma?
- Age
- Gender (M>F)
- Carcinogens: smoking, arylamines, radiotherapy, cyclophosphamide
How does urothelial cell carcinoma present?
- Haematuria
- Urinary frequency
- Pain on urination
- Urinary tract obstruction
For Transitional cell carcinoma what is the:
- Prognosis
- Morphology
- Staging
- Grading
- P=5yr survival rate=73%
- S&G= TNM staging
- M=papillary tumor with stratified, nonkeratinizing epithelium supported on a thin fibrovascular core
Describe reflux nephropathy?
-Interstitial & glomerular damage due to reflux from the bladder to the kidneys resulting in small, scarred kidneys
-ureters do not attach properly to the bladder, incompetent valves, congenital, bladder outlet obstruction, enlarged prostate, bladder stones, neurogenic bladder
-Child with UTI, bedwetting
-Leads to proteiuria, kidney failure & hypertension
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