Monday 8 November 2010

MRCP revision battle 43.2: Polycystic kidney disease and renal cysts

The classical cause of renal cysts is polycystic kidney disease.


Polycystic kidney disease affects around 1:1000.  


Type 1 is inherited on chromosome 16
Type 2 is inherited on chromosome 4


The US criteria for diagnosing polycystic kidney disease in a patient with a positive family history is:
  • 2 cysts if aged less than 30
  • 2 cysts in both kidneys if aged 30-59
  • 4 cysts in both kidneys if aged greater than 60

Signs/symptoms of polycystic kidney disease include:
  • renal enlargement
  • abdominal pain
  • hypertension
  • renal failure

Associated features include:
  • liver cysts
  • subarachnoid haemorrhage
  • mitral valve prolapse


Other causes of renal cysts include:
  • autosomal recessive polycystic kidney disease
    • chromosome 6
    • tend to develop end stage renal failure in childhood
    • fibrosis of liver
  • Von-Hippel-Lindau (see battle 15.2)
    • autosomal dominant on chromosome 3
    • pre-maligant
  • tuberous sclerosis
    • auto dom on chromosome 9 or 16
  • simple cysts
    • occur in less than 2% of under 50s but up to 20% of over 70s.


Now for some renal tubular acidosis...