L82 – Congenital and Developmental Abnormalities of the Urinary Tract Flashcards Preview

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Flashcards in L82 – Congenital and Developmental Abnormalities of the Urinary Tract Deck (88):
1

What are the 3 types of abnormalities in renal tissue?

Abnormalities in amount of renal tissue

Anomalies in shape and position

Abnormalities of differentiation

2

Name the 2 Abnormalities in amount of renal tissue?

• Agenesis (Failure to form)

• Hypoplasia (Failure to develop to normal size)

3

Name the 2 Abnormalities in shape and position of renal tissue?

• Horseshoe kidneys

• Ectopic kidney (abnormal position)

4

What is the consequence of Bilateral agenesis of renal tissue?

Decrease urine production by fetus in utero

cause significant oligohydramnios - very low amount of amniotic fluid in sac

>> Potter's sequence

5

Renal tissue hypoplasia is commonly bilateral or not? What is the consequence of bilateral hypoplasia?

• More commonly unilateral
• Bilateral cases usually develop renal failure in
childhood

6

Describe the shape of horseshoe kidney?

Kidneys too close to each other >> fuse (usually at lower
poles)

7

What are the common abnormal positions of ectopic kidneys? Size?

Just above pelvic brim or in pelvis

Normal or slightly small in size

8

What is the consequence of ectopic kidney on ureter?

• Kinking/tortuosity of ureters may lead to
obstruction -> predispose to infection

9

What is the main source of amniotic fluid?

Urine

10

Name of Reduction in amount of amniotic
fluid?

Oligohydramnios

Lead to Potter's sequence

11

Is Potter's sequence a syndrome? Define?

NOT syndrome

Cascade of anomalies triggered by one initiating aberration

12

How does Potter's sequence occur?

result of significant oligohydramnios of whatever cause

13

Name 3 causes of Potter's sequence?

• Bilateral renal agenesis

• Infantile polycystic kidney disease

• Chronic leakage of amniotic fluid etc.

14

What does Oligohydramnios lead to? Give 4 examples of results?

• Oligohydramnios lead to fetal compression


• Flattened facies
• Positional abnormalities of hands and feet
• Dislocation of hip
• Hypoplastic lungs (resp. failure)

15

What is Flattened facies seen in Potter's sequence?

compression of ears, nose;

underdevelopment of lower jaw > receding chin

16

Name the 2 abnormalities of differentiation and their subtypes?

• Multicystic Renal Dysplasia

• Polycystic kidney disease
>> Autosomal recessive or Dominant

17

Difference in onset between the 2 types of Polycystic kidney disease?

• Autosomal Recessive (Childhood)
• Autosomal Dominant (Adult)

18

Give the embryonic developmental abnormality for multicystic renal dysplasia?

Developmental abnormality of metanephric duct

>> resulting in aberrant
differentiation of metanephric blastemal

19

Is Multicystic renal dysplasia hereditary?

Sporadic disorder, NOT hereditary

20

Is Multicystic renal dysplasia pre-neoplastic?

No

21

What are the types/ variations of Multicystic renal dysplasia?

• Unilateral or bilateral, segmental or focal

22

Size and shape of affected kidneys in Multicystic renal dysplasia?

may be small or enlarged

Multiple cystic structures deform the kidney

23

What is associated with Multicystic renal dysplasia?

Characteristic presence of cartilage and primitive tubules


Associated with:
- ureteric atresia (abnormal narrowing)

- lower urinary tract obstructive lesion

24

What causes Childhood polycystic kidney disease?

Autosomal recessive condition, Most cases caused by mutations of PKHD1 gene

25

What does PKHD1 gene encode for?

fibrocystin

26

What are the subcategories of Childhood polycystic kidney disease?

Perinatal, Neonatal, infantile and juvenile

27

Consequence of Autosomal Recessive (Childhood) Polycystic
Kidney Disease?

early infantile death – Potter’s sequence

28

How does Autosomal Recessive (Childhood) Polycystic
Kidney Disease change kidney morphology, location?

Bilateral / symmetrical enlarged kidneys

Fusiform dilatation of collect ducts (radially arranged)

Can become large enough to push anteriorly, not retroperitoneum

29

Size of liver and lungs in AR Polycystic
Kidney Disease?

Large liver

Small lungs

30

Explain the formation of large liver in AR Polycystic Kidney Disease?

congenital hepatic fibrosis

> More prominent, thicker portal tracts, fibrotic bands extend between hepatocytes

31

How does congenital hepatic fibrosis lead to Portal Hypertension?

Congential hepatic fibrosis leads to abnormal proliferation of epithelium in bile duct

> Increase in portal fibrovascular tissue

> Increase connection of biliary arterial blood (high BP) with portal venous system (low BP)

32

What is the mode of death in AR Polycystic Kidney Disease?

neonatal renal failure >> uremia (azotemia)

Neonatal respiratory failure from small (hypoplastic) lungs

33

Explain the formation of hypoplastic lungs in AR polycystic kidney disease?

Big liver compresses thoracic cavity

decrease urinary output can cause oligohydramnios > compression on thoracic cavity

34

What is the cause of adult polycystic kidney disease?

Autosomal dominant
Mutation of mostly PKD1 (ch.16), and less commonly PKD2 (ch.4)

Cysts gradually develop over time, but pathogenesis not well established

35

Gene frequency of adult polycystic kidney disease?

• Gene frequency about 1 in 1,000

36

Pathology of adult polycystic kidney disease?

Numerous cysts in cortex and medulla

>> distention causing nodular huge kidneys

37

Difference between the 2 types of mutations leading to adult polycystic kidney disease?

1. PKD1 (chromosome 16) = 80% cases


2. PKD2 (chromosome 4) = usually milder disease
(can be asymptomatic until old age)

38

Clinical presentation of Adult polycystic kidney disease at middle age?

 Abdominal mass
 Pain
 Haematuria
 Hypertension
 Chronic renal failure

39

Gross morphology of Adult polycystic kidney disease?

Numerous cysts in cortex, medulla:
 Contain urine / fluid
 May be black due to hemorrhage

>> compression/ tangle with tubules

40

Associrated conditions of Adult polycystic kidney disease?

Berry aneurysms of cerebral arteries

Polycystic liver, lungs, pancreas

Diverticulosis of large intestines

Cardiac valve abnormalities

41

What are the consequences of Polycystic liver, lungs?

 Liver (biliary cysts may compress on bile ducts)
 Lungs (cysts may compress on airways)

42

What is Diverticulosis of large intestines?

herniation of mucosa out of muscular wall of
intestines (can progress into peritonitis)

43

What are the consequences of Berry aneurysms of cerebral arteries?

if rupture: subarachnoid hemorrhage

Increase intracranial pressure to death

44

What is the prenatal early diagnosis of AR polycystic kidney disease?

molecular genetic studies for PKD1, PKD2 (usually by genetic linkage studies)

45

What is the Teenage early diagnosis of AR polycystic kidney disease?

ultrasound (cysts may start to form)

46

What causes acquired cystic kidney disease?

NOT GENETIC

Develops in end stage renal failure when a patient after dialysis for many years

47

What does acquired cystic kidney disease look like?

AR polycystic kidney disease

But these are completely different in cause

48

Explain how Acquired cystic kidney disease occurs?

glomerular disease = atrophy of tubules

Tubular cells may undergo hyperplastic change, forming cysts or even carcinoma

49

What are the 5 congenital abnormalities of the ureter>?

• Duplication (bifid ureter)
• Valve
• Stricture
• Abnormal course, e.g. retrocaval ureter
• Ectopic opening

50

What is Retrocaval ureter?

When ureter wind around Inferior vena cava
>> ureter may get
obstructed easily, causing infection

51

How can valve defect occur in congenital ureter abnormalities?

mucosal redundance, e.g. in posterior
portion of urethra

52

Give an example of ectopic opening of ureter>?

open in vagina > urinary
incontinence (dripping)

53

What are the causes of extrophy of urinary bladder?

Causes:
 Defect of pubic symphysis/ anterior abdominal wall

 Defect of bladder

 Malformed external genitalia

54

What are the complications of chronic exposure of urinary bladder extrophy?

 Infection
 Adenocarcinoma arising from urachus

55

What are the 3 urachal anomalies?

Urachal cyst

Fistulous urinary tract

Patent urachus remains


(+umbilical urachal sinus, vesicourachal diverticulum)

56

How do urachal cysts form?

• Only central part of urachus persists
• Can lead to carcinoma in future

57

3 Congenital abnormalities of urethra in male?

Hypospadias

Epispadias

Urethral valve

58

What is hyposapdias?

• Abnormal urethral opening of
the ventral surface of penis

59

What is episapdias?

• Abnormal urethral opening on
the dorsal surface of penis

60

What are the 3 complications of episadias?

1) Associated with other
malformations of the urinary tract

2) Increase risk of urinary tract obstruction and ascending UTI

3) Affect normal ejaculation and insemination = subfertility

61

Consequences of urethral valve abnormality in urethra?

*usually in male at posterior urethra*

Dilation of proximal urethra due to constriction of urethral valve

62

What are the 6 common obstructive lesions/ UT obstructions?

-Male: BPH
-Female: Pregnancy
-Renal stones (Calculi)

-Neurogenic bladder
-Infection/ inflammation (TB kidney)
-Urothelial tumours

63

What are the variations of Urinary tract Obstruction/ Obstructive uropathy?

Acute or Insidious; Partial or Complete; Unilateral or Bilateral

64

What are associated complications of UT obstruction?

-Stone formation
-UTI
-Permanent renal damage, impair renal function

65

Acute ureteric obstruction causes___?

acute renal colic = severe pain radiates from loin at back to suprapubic region

66

Most common cause of acute renal colic?

Caused by acute ureteric obstruction, Commonly Renal stones

67

Unrelieved UT obstruction always
leads to ___ ?

permanent renal
damage and impairment of renal function + Infection

68

What are 2 outcomes that changes morphology of urinary system due to UT obstruction?

hydronephrosis and/or
hydroureter

69

Most common site of Calculi formation? Another name for Renal stone?

Urolithiasis

Most commonly formed in Kidney
• But may form anywhere in urinary tract

70

How does a calculi in the kidney cause obstruction elsewhere?

dislodge and migrate to distal part of urinary tract

71

Age and gender most affected by Renal stones?

Men >> Women

Peak age: 20-30 years old

72

Name major types of renal stones?

• Calcium oxalate and phosphate stones (70%)

• Magnesium ammonium phosphate stones (Struvite) (5-10%)

• Uric acid stones (5-10%)

• Cystine stones (1-2%)

73

Formation of calcium oxalate and phosphate stones is related to?

hyperparathyroidism, renal tubular acidosis

>> leading to hypercalciuria and hypercalcaemia

74

Formation of Struvite stones is related to?

infections by urea-splitting bacteria e.g. Proteus > Staghorn calculi may form

75

Formation of Uric acid stones is related to?

hyperuricaemia, e.g. Gout

76

Formation of Cystine stones is related to?

genetic defects of renal reabsorption of amino acids, including cystine

77

Bladder outflow obstruction can lead to which complications?

UTI

Bladder hypertrophy - trabeculation

Bladder diverticuli (pouch in bladder wall)

BILATERAL hydroureter and hydronephrosis

Vesicoureteral reflux

Acute retention of urine = acute renal failure

78

What are lower urinary tract symptoms?

1) Weak stream
2) Hesitancy
3) Dribbling
4) Urinary frequency and nocturia

79

How to show Vesicoureteral reflux on scanes?

voiding cystogram with radiologic contrast filling the bladder via a closed bladder catheter

80

What causes vesicourethral reflux?

Rise in intravesical pressure

81

What does the severity of reflux depend on?

intravesical pressure

competence of valve-like effect at the vesicoureteral junction

82

What is the Grading System of
Vesicoureteral Reflux?

From grade I to grade V

Reflux extends further up urinary tract

Increasing dilatation and tortuosity of urinary tract

83

When can vesicourethral reflux cause scarring of kidney?

1. Sterile reflux occurs at high pressure
2. Urine gets infected (chronic pyelonephritis)

84

What are the 4 types of renal scarring?

Mild
Severe
Back-pressure
End-stage

85

Describe the scarring of kidneys due to vesicourethral reflux?

 Scar tends to affect upper / lower polar areas (more prone to intrarenal reflux)


 Deep cortical scar corresponds with scar in medulla

86

Causes of papillary necrosis?

1. Diabetes mellitus
2. Analgesic nephropathy
3. Hemoglobinopathies, such as sickle cell
anemia
4. Complication of urinary obstruction + infection

87

Papillary affects kidneys bilaterally or not?

• Usually bilateral but may be unilateral

88

4 effects of papillary necrosis?

1) Hematuria
2) Renal colic (pain)
3) Acute / chronic renal failure
4) Inflammation and regeneration predispose to urothelial cancer

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