(32) Renal System Disease 2 Flashcards
1
Q
What is obstructive uropathy?
A
Obstruction of the urinary tract - can occur anywhere from renal pelvis to urethral meatus
2
Q
Obstructive uropathy can be… (classifications)
A
- chronic or acute
- unilateral or bilateral (rare)
- intrinsic or extrinsic
3
Q
What are the types of obstruction that can occur in the renal pelvis?
A
- calculi
- tumours
- ureteropelvic strictures
4
Q
Give an example of a type of renal pelvis calculi
A
Staghorn calculus
- large and difficult to remove
5
Q
What happens when there is a ureteral stricture?
A
The kidney and ureter becomes distended above the stricture
6
Q
What are types of intrinsic ureter obstructions that can occur?
A
- calculi
- tumours
- clots
- sloughed papillae
- inflammation
7
Q
What are the types of extrinsic ureter obstructions that can occur?
A
- pregnancy
- tumours (eg. cervix)
- retroperitoneal fibrosis
8
Q
What can occur at the vesicoureteral junction to cause obstruction?
A
Vesicoureteral reflux (defective valve causing reflux of urine up ureter)
- only seen in male patients
9
Q
At what areas can urinary tract obstruction occur?
A
- renal pelvis
- ureter (intrinsic and extrinsic)
- bladder
- urethra
- prostate
10
Q
Give examples of obstruction that can occur at the level of the bladder
A
- calculi
- tumours
11
Q
Give examples of obstruction that can occur at the level of the urethra
A
- posterior urethral valve stricture
- tumours (rare)
12
Q
What conditions of the prostate may cause urinary tract obstruction?
A
- hyperplasia
- carcinoma
- prostatitis
(surrounds urethra so enlargement may cause blockage)
13
Q
What are the types of obstruction that occur within the lumen of the urinary tract?
A
- urinary calculi
- strictures
- neoplasia
14
Q
Give 3 classifications of strictures
A
- post-procedural
- post-infective
- congenital
15
Q
What are the types of obstruction that occur due to abnormalities of the wall of the urinary tract?
A
- neoplasia (benign or malignant)
- congenital anatomical abnormalities
16
Q
What are the types of obstruction that occur due to external compression?
A
- tumours outside of the urinary tract
- inflammatory conditions (retroperitoneal fibrosis)
- pregnancy
17
Q
What are the types of obstruction that can be classified as functional obstruction?
A
- neurological conditions
- severe reflux
18
Q
What is the typical sequelae of urinary tract obstruction?
A
- infection (cystitis, ascending pyelonephritis)
- stone/calculi formation (both cause and result of obstruction)
- kidney damage (acute or chronic)
19
Q
The consequences of urinary tract obstruction depend on…
A
- site of obstruction
- degree of obstruction
- duration of obstruction
20
Q
Give an example of a consequence of urethral obstruction (bladder outlet obstruction)
A
Detrusor hypertrophy and trabeculation
21
Q
Give examples of consequences of ureteric obstruction
A
- hydroureter (whole system dilated and kidneys shrunken and scarred)
- hydronephrosis (dilated calyces and pelvis and cortical atrophy)
22
Q
What are the resulting consequences of acute complete obstruction?
A
- reduction in GFR
- mild dilatation and mild cortical atrophy
CAN CAUSE ACUTE RENAL FAILURE
23
Q
Give 2 potential pathways following partial/intermittent obstruction
A
- continued GFR
- dilatation of pelvis and calyces
OR
- filtrate passes back into interstitium
- compression of medulla
- impaired concentrating ability
24
Q
What is the end result following partial or intermittent obstruction?
A
Eventual cortical atrophy, fall in renal filtration, and renal failure
25
How does acute bilateral obstruction present?
- pain
- acute renal failure
- anuria
26
How does chronic unilateral obstruction present?
- asymptomatic initially
| - cortical atrophy and reduced renal function if unresolved
27
How does bilateral partial obstruction present?
Initially polyuric with progressive renal scarring and impairment
28
What does polyuric mean?
Excessive passage of urine
eg. in diabetes
29
What is the word for the formation of renal calculi?
Urolithiasis
30
How many people does urolithiasis/renal calculi affect?
7-10% of the population - increasing
31
Which gender is affected more by renal calculi/urolithiasis?
Male predominance
32
What is the peak onset age for renal calculi?
20-30
33
Where do renal stones form?
Can form anywhere in the urinary tract but most commonly in the kidney
34
What is the pathogenesis behind renal calculi?
- excess of substances which may precipitate out eg. Ca+
- change in urine constituents causing precipitation of substances eg. change in pH
- poor urine output (supersaturation)
- decreased citrate levels
35
What are the different types of stones (classified by composition)?
- calcium stones
- struvite stones
- urate stones
- cystine stones
Different stone types arise for different reasons
36
What is the most common type of renal stone by composition?
Calcium stones (70%)
37
What do calcium stones consist of?
Calcium oxate +/- calcium phosphate
38
What do struvite stones consist of?
(15%) - magnesium ammonium phosphate
39
What do urate stones consist of?
(5%) - uric acid
40
The most commonly identified cause of calcium stones is what?
Hypercalciuria
41
Caclium stones are most commonly caused by hypercalciuria which is due to...
- hypercalcaemia
- excessive absorption of intestinal Ca+
- inability to reabsorb tubular Ca+
- idiopathic
42
Hypercalcaemia may lead to hypercalciuria which causes calcium stones. What are the causes of hypercalcaemia?
- bone disease
- PTH excess
- sarcoidosis
43
What are the other risk factors (other than hypercalciuria) for calcium stones?
- gout (forms a core for Ca+ crystal formation)
| - hyperoxaluria (hereditary, excess dietary intake)
44
What is hyperoxaluria?
An excessive urinary excretion of oxalate. Patients often have calcium oxalate kidney stones. It is sometimes called Bird's disease.
45
What are the stages in the formation of struvite stones
- urease produced by bacterial infection (proteus)
- urease converts urea to ammonia
- causes rise in urine pH
- precipitation of of magnesium ammonium phosphate salts
- large staghorn calculi
46
Most staghorn calculi are what type of urinary stone?
Struvite stones
47
What are the causes of urate stones?
- hyperuricaemia (gout, patients with high cell turnover eg. leukaemia)
- idiopathic
48
When do cystine stones occur?
- rare
| - occur in presence of inability of kidneys to reabsorb amino acids
49
What is the gold standard investigation for renal calculi?
Non-contrast CT scanning (sensitivity of >95%)
50
What investigation would you use for renal calculi in pregnancy or where CT not possible?
Ultrasound (30-67% sensitive)
51
When would you used ultrasound for renal calculi?
In pregnancy or where CT is not possible
52
Other than CT and ultrasound, name another investigation for renal calculi
Intravenous urography (70% sensitive for stones)
53
What is the possible sequelae in renal calculi?
- obstruction
- haematuria
- infection
- squamous metaplasia/squamous cell carcinoma
54
Renal cell carcinomas make up what proportion of cancers?
3%
55
The vast majority of renal carcinomas are...
Clear cell
56
Most renal carcinomas are clear cell but rarer variants include..
Papillary and chromophobe cell
57
What is the peak age for renal cell carcinoma?
65-80
58
Which gender is affected more by renal cell carcinoma?
Male > female (3:2)
59
What are the risk factors for renal carcinoma?
- tobacco
- obesity
- hypertension
- oestrogens
- acquired cystic kidney disease (due to chronic renal failure)
- asbestos exposure
60
What is the most common of several cancer syndromes in RCC?
Von Hippel-Lindau syndrome
61
What is the VHL gene required for?
Breakdown of Hypoxia Inducible Factor-1 (HIF-1) oncogene
62
What does loss of VHL gene function cause?
Cell growth and increased cell survival
63
VHL gene mutations are commonly identified in what cancers?
Tumours develop in kidneys, blood vessels, pancreas
Commonly identified in clear cell renal cell carcinoma
64
What are the local symptoms of renal carcinoma?
- haematuria
- palpable abdominal mass
- costovertebral pain
(late presentation - systemic symptoms or metastases 25%)
- paraneoplastic syndromes
65
What are paraneoplastic syndromes?
Clinical syndromes caused by tumours
- not related to the tissue that the tumour arose from
- not related to invasion by the tumour itself or its metastases
66
What are the paraneoplastic syndromes associated with RCC?
- Cushing's syndrome
- hypercalcaemia
- polycythaemia
67
What is Cushing's syndrome?
Prolonged exposure to cortisol (excess ACTH stimulating adrenal cortex to produce high levels of cortisol)
68
What is polycythaemia?
Abnormally increased concentration of haemoglobin in the blood, either through reduction of plasma volume or increase in red cell number (related to erythropoietin)
69
What is erythropoetin?
Hormone secreted by the kidneys that increases the rate of production of red blood cells in response to falling levels of oxygen in the tissues
70
Which hormones are the paraneoplastic syndromes related to RCC related with?
Cushing's syndrome - ACTH
Hypercalcaemia - parathyroid hormone related peptide
Polycythaemia - erythropoietin
71
Describe the morphology of RCC in clear cell RCC
- well defined yellow tumours
- often with haemorrhagic areas
- may extend into perinephric fat or into renal vein
72
Describe the morphology of RCC in papillary RCC
- more cystic
| - more likely to be multiple
73
Describe the microscopy in clear cell RCC
- clear cells
- delicate vasculature
- usually small bland nuclei
74
Describe the microscopy in papillary RCC
- cuboidal, foamy cells
| - surrounding fibrovascular cores often containing foamy macrophages or calcium
75
What is the average 5 year survival for RCC?
45%
76
What is the 5 year survival for RCC if organ confined?
>70%
77
What is the 5 year survival for tumours extending into perinephric fat or renal vein?
50%
78
What is the 5 year survival for RCC with distant metastases?
Very poor prognosis (
79
95% of bladder tumours are what type?
Urothelial cell carcinoma
80
Where do urothelial cell carcinomas arise from?
The specialised multilayered epithelium - most common in bladder but may arise anywhere from renal pelvis to urethra
81
What are the risk factors for urothelial cell carcinoma?
- age
- gender (male>female)
- carcinogens:
- smoking
- arylamines
- cyclophosphamide
- radiotherapy
82
What is the most common sign of urothelial cell carcinoma?
Haematuria
83
How does urothelial cell carcinoma present?
- haematuria
- urinary frequency
- pain on urination
- urinary tract obstruction
84
What is urothelial cell carcinoma also known as?
Transitional cell carcinoma
85
What are the different histological patterns in TCC?
- papilloma-papillary carcinoma
- invasive papillary carcinoma
- flat non-invasive carcinoma (CIS)
- flat invasive carcinoma
86
Describe the T staging in bladder carcinoma (depth of invasion)
```
Ta = noninvasive, papillary
Tis = carcinoma in situ (nonivasive, flat)
T1 = lamina propria invasion
T2 = muscularis propria invasion
T3a = microscopic extra-vesicle invasion
T3b = grossly apparent extra-vesicle invasion
T4 = invades adjacent structures
```
87
Describe the prognosis in TCC/UCC?
- recurrences are common
- outcome depends on grade and stage
- poor prognosis for metastatic disease
88
How does grade affect prognosis for TCC/UCC?
Low grade TCC = 98% alive at 5 years
89
How does stage affect prognosis for TCC/UCC?
Muscle invasion = 60% 5 year survival
