Cystic Disease

Question 1

who gets it?

Answer 1

can be inherited or acquired

Bosniak score - predicts cancer

Question 2

Who gets Autosomal Dominant Polycystic Disease?

Answer 2

the most frequent life-threatening hereditary disease
incidence 1:400 - 1:1000
important cause of ESRD

Question 3

what chromosomes are PKD?

Answer 3

PKD1 - chromosome 16

PKD2 - chromosome 4

Question 4

what is the pathology of autosomal dominant polycystic disease?

Answer 4

cyst enlargement
large kidneys
epithelial lined cysts arise from a small population of renal tubules
benign adenomas 25% of kidneys - sometimes can progress to malignancy

Question 5

how does autosomal dominant polycystic disease present renally?

Answer 5

• reduced urine concentration ability
• chronic pain
• hypertension common (early)
• haematuria (cyst rupture, cystitis, stones)
• cyst infection
• renal failure

Question 6

what are the extra-renal clinical features of autosomal dominant polycystic disease?

Answer 6

hepatic - most common extra-renal presentation
- liver cysts present 10 yrs after renal cysts
- liver function generally preserved
- SoB, pain, ankle swelling
intra-cranial aneurysm
- 4-8%, clusters of family members
- anterior circulation
- screening is indicated in patients with FHx
cardiac disease
- mitral/ aortic valve prolapse
- valvular disease - collagenous/myzomatous degeneration
diverticular disease
- increased in patients on dialysis with ADPKD
- diverticulitis & colonic perforation are complications
hernias
- increased incidence of abdominal/ inguinal hernias (45%)

Question 7

how is ADPKD investigated?

Answer 7

Imaging
US - presence of multiple bilateral cysts
renal enlargement
CT/MRI - when unclear on USS
genetic
linkage analysis
mutation analysis - available on the NHS
(genetic counselling - 50% likely in offspring, counselling both pre and post testing will be needed)

Question 8

how is ADPKD managed?

Answer 8

hypertension - rigorous control 
hydration 
proteinuria reduction 
cyst haemorrhage + cyst infection 
Tolvaptan - reduce cyst volume and progression - carbonic anhydrase inhibitor 
renal failure 
- dialysis 
- transplantation 
- CV and cerebrovascular causes - death

Question 9

how does ADPKD present in children?

Answer 9

can present in uteri/ 1st year of life
siblings are at increased risk of early disease
renal involvement is similar to adults
a single cyst in high risk patients is enough for a diagnosis
cerebral aneurysm is rare in children
distinguishing ARPKD difficult - USS suggestion of congenital hepatic fibrosis suggests ARPKD

Question 10

what is the pathology of autosomal recessive PKD?

Answer 10

renal involvement is bilateral and symmetrical
urinary tract is generally normal
cyst appear from collecting duct (30-90% ducts)

Question 11

who gets ARPKD?

Answer 11

young children
associated with hepatic lesions
rare 1:20,000
PKDH1 gene on chromosome 16

Question 12

how does ARPKD present?

Answer 12

varies - depending on renal/liver lesions
relevance is distinguishing between severe forms and one which survive the neonatal period
kidney is always palpatable
hypertension
recurrent UTI

Question 13

what is the prognosis of autosomal recessive polycystic kidney disease?

Answer 13

slow decline in GFR - less than 1/3 reach dialysis
better prognosis than ADPKD because so few AR reach dialysis
30-50% of children with ARPKD are severely affected
if you survive the neonatal period 9-24% mortality in the 1st year
if you survive the 1st year - 80% survive beyond 15 years