Flashcards in Diseases of urinary tract 2 Deck (35):
What are the common causes of obstruction at the renal pelvis?
Calculi - renal stone
What stones are large, difficult to remove and have to be broken down?
What are the main intrinsic causes of acute obstruction at the level of the ureter?
Slough (from inflammation)
Clots (usually road traffic accidents)
What type of obstructions are there?
Extrinsic - from outside the ureter
What are the main extrinsic causes of obstruction at level of ureter?
Tumours e.g. cervix
What is vesicoureteral reflux?
Usually occurs in young gilder (male, congenital)
Reflux of urine due to dysfunction; ureteral valves)
What is an important cause of obstruction in older males? (>60yrs)
Prostate - hyperplasia, carcinoma, prostatitis - constricts urethra
What happens if there is an obstruction at level of urethra?
Whole system gets dilated (children)
Name a functional cause of renal obstruction?
Neurological conditions e.g. spinal cord injury
What are the main sequelae of renal obstruction and renal stasis?
Urinary tract infection - cystitis, pyelonephritis
What can obstruction at the urethral level cause? What it caused by?
Bladder hypertrophy (detrusor hypertrophy)
Due to prostatic hyperplasia
What is the main consequence of obstruction to the kidney? Whats it characterised by?
- Dilated pelvis and calyces
What can acute complete obstruction cause to the kidney? How is it characterised?
Can reduce GFR and cause acute renal failure
Mild hydronephrosis mild dilatation of pelvis and calyces (not enough time for large dilation)
What can chronic intermitted obstruction cause to the kidney? How is it characterised?
Eventual (slow) cortical atrophy, reduced renal filtration and renal failure
What are the clinic features of complete acute obstruction?
-Acute renal failure
What are the clinical features of chronic unilateral obstruction?
- Eventual cortical atrophy and reduced renal function
What are the features of bilateral partial obstruction?
Polyuria and progressive scarring/reduced function
What is the pathogenesis for renl calculi?
Excess substances in URINE precipitating out e.g. calcium
Change in urine constituents causing substance precipitation e.g. pH
Poor urine output - supersaturation
- reduced citrate
What are the main types of renal stones that can occur?
Struvite (15%) - infections (staghorn)
Urate (5%) - acidic urine
What are the main causes of calcium stones?
- Hypercalcaemia due to bone disease, excessive PTH, sarcoidosis
- Excessive Ca absorption from intestine
-Inability to reabsorb tubular Ca
Gout - allows Ca to accumulate!
Whats the pathogenesis of struvite stones?
Urease producing bacteria infection -> convert urea to ammonium -> increases urine pH -> precipitates Mg ammonium phosphate salts -> stag horn stones
What are the main cause of urate stones?
What are the main cause of cystine stones?
Inability of kidneys to reabsorb AAs
What is the gold standard means of investigating for renal calculi?
Non-contrast CT scan
What are the sequelae of renal calculi?
Squamous metaplasia (squamous cell carcinoma)
What is the most common type of renal carcinoma?
Clear cell carcinoma
What is the most important risk factor for renal carcinoma?
-Acquired cystic kidney disease
What is the most common cancer syndrome observed in renal cell carcinoma?
Von Hippel Lindau syndrome
What are the clinical presentations of renal cell carcinoma?
Palpable ab mass
MOSTLY INCIDENTAL finding
Provides some examples of paraneoplastic syndromes associated with RCC
Cushing syndrome - ACTH
Hypercalcamia - PTH
Polycythaemia - EPO production
What is the characteristics of a clear cell carcinoma?
Well defined, yellow tumour
Often with haemorrhagic areas
May extend into perinephric fat or into renal vein (poorer prognosis)
Where do the majority of urothelial cell carcinomas arise?
Most commonly bladder but can come from the renal pelvis to urethra
What is the most common risk factor for urothelial carcinoma?
How do urothelial cancers present?
Pain on urination
Urinary tract obstruction