Renal System 2

Question 1

What is obstructive uropathy?

Answer 1

• Obstruction of urinary tract
• Anywhere from renal pelvis to urethral meatus
• Chronic or acute
• Unilateral or bilateral

Question 2

What are causes of urinary tract obstruction in the kidney pelvis?

Answer 2

• Calculi
• Tumours
• Ureteropelvic stricture

Question 3

What are intrinsic causes of urinary tract obstruction in the ureter?

Answer 3

• Tumours
• Calculi
• Clots
• Sloughed papillae
• Inflammation

Question 4

What are extrinsic causes of urinary tract obstruction in the ureter?

Answer 4

• Pregnancy
• Tumours (cervix)
• Retroperitoneal fibrosis

Question 5

What are causes of urinary tract obstruction in the prostate?

Answer 5

• Hyperplasia
• Carcinoma
• Prostatitis

Question 6

What are causes of urinary tract obstruction in the bladder?

Answer 6

• Calculi
• Tumours
• Severe reflux
• Neurological conditions

Question 7

What can acute complete obstruction lead to?

Answer 7

• Reduction in gloerular filtration rate
• Mild dilatation & mild cortical atrophy
• Can cause acute renal failure

Question 8

What can partial or intermittent obstruction lead to?

Answer 8

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

Question 9

What are the clinical features of urinary tract obstruction?

Answer 9

• Pain
• Acute renal failure & anuria
• Bilateral partial obstruction= polyuric with progressive renal scarring & impairment

Question 10

What are the pathogenesis of urinary tract obstruction?

Answer 10

• 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

Question 11

What is the classification of urinary tract obstruction? (types of stones)

Answer 11

• Calcium stones
• Struvite stones
• Urate stones
• Cystine stones
• Different stones for different reasons

Question 12

What causes calcium stones?

Answer 12

-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)

Question 13

How are struvite stones formed?

Answer 13

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

Question 14

How are urate stones formed?

Answer 14

• Hyperuricaemia (Gout, high cell turnover-leukaemia)

- Idiopathic

Question 15

How are cystine stones formed?

Answer 15

• Rare

- Occur in presence of inability of kidneys to reabsorb amino acids

Question 16

What can urinary tract obstruction lead to?

Answer 16

• Haematuria
• Infection
• Suamous metaplasia +/- squamous cell carcinoma

Question 17

What are risk factors for renal cell carcinoma?

Answer 17

• Tobacco
• Obesity
• Hypertension
• Oestrogen
• Acquired cystic kidney disease (due to chronic renal failure)
• Asbestos exposure

Question 18

What is Von Hippel-Lindau Syndrome?

Answer 18

• 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

Question 19

What is the presentation of renal cell carcinoma?

Answer 19

• Haematuria
• Palpable abdominal mass
• Costovertebral pain
• Late presentation: systemic symptoms or metastases

Question 20

What are paraneoplastic syndromes?

Answer 20

• Syndromes caused by tumours
• Not related to the tissue that the tumour arose from
• Not related to invasion by tumour itself/metastases

Question 21

Name some paraneoplastic syndromes associated with renal cell carcinoma

Answer 21

• Cushing’s syndrome (ACTH)
• Hypercalcaemia (parathyroid hormone related peptide)
• Polycythaemia (erythropoietin)

Question 22

Describe the morphology of renal cell carcinoma

Answer 22

• 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

Question 23

Describe a renal cell carcinoma microscopically

Answer 23

-Delicate vasculature
-Small bland nuclei
-Papillary tumours:
Cubiodal, foamy cells
-Surrounding fibrovascular cores often containing foamy macrophages or calcium

Question 24

What is urothelial cell carcinoma/transitional cell carcinoma?

Answer 24

• 90% of all bladder Ca
• Bladder tumours
• Arising from specialised multilayered epithelium
• May arise anywhere from renal pelvis to urethra

Question 25

What are the risk factors for urothelial cell carcinoma?

Answer 25

• Age
• Gender (M>F)
• Carcinogens: smoking, arylamines, radiotherapy, cyclophosphamide

Question 26

How does urothelial cell carcinoma present?

Answer 26

• Haematuria
• Urinary frequency
• Pain on urination
• Urinary tract obstruction

Question 27

For Transitional cell carcinoma what is the:

• Prognosis
• Morphology
• Staging
• Grading

Answer 27

• P=5yr survival rate=73%
• S&G= TNM staging
• M=papillary tumor with stratified, nonkeratinizing epithelium supported on a thin fibrovascular core

Question 28

Describe reflux nephropathy?

Answer 28

-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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