mindmap - Renal cystic diseases

cystic diseases of the kidney

• general characteristics
  • heterogenous group
    comprising these types
    of pathologies
    • hereditary
    • developmental non hereditary
    • acquired
    they are important because
    • reasonably common and present diagnostic problem
    • some forms e.g. APKD major cause of CRF
    • can occasionally be confused with malignant tumours
    emerging theme in the pathophysiology
    is that the underlying defect is with the
    cilia-centrosome complex of tubular epithelial cells
• simple cysts
  • morphology
    • lesions occring multiple or single cystic spaces.
    • 1-5cm in diameter
    • translucent
    • lined by a gray, glistening smooth membrane
    • filled with clear fluid
  • may be found due to
    • autopsy
    • incidental finding
    • pain and hemorrhage
  • benign
  • Dialysis - associated acquired cysts
    • in end-stage renal disease
    • dialysis
    • present in cortex and medulla
    • may bleed
• Adult Dominant Polycystic Disease
  • characteristics
    • seen in 1/500-1000 people.
    • 10% of cases of Chronic Renal Failure
    • genetically heterogenous
    • PKD1 gene on short arm of chromosome 16
  • pathogenesis
    • PKD 1 gene produced polycystin molecule
      polycystin has regions of homology with
      proteins involved in cell-cell / cell-matrix adhesion
      resultant defect in cell-matrix interactions cause
      • proliferation
      • adhesion
      • differentiation
      • matrix production
      cyst formations
  • morphology
    • gross
      • kidney reach massive size
        • weigh up to 4kg each
        • readily palpable
        • mass extend to pelvis
        kidney seems to be composed
        solely of mass of cysts 
        • filled with fluid
          • clear
          • turbid
          • hemorrhagic
    • microscopic
      • normal parenchyma dispersed among the cysts
  • clinical course
    • usually does not produce symptoms till 4th decade
    • common presenting complaint
      • flank pain
      • dragging sensations
    • acute distention of cyst
      • intracystic hemorrhage
      • obstruction
      • cause excrutiating pain
    • abdominal distension
    • intermittant gross hematuria
    • complication
      • hypertension
        • in 75% of patients
        urinary indection
        saccular aneurysms of
        circle of willis in 10-30%
        • SAH
    • prognosis
      • ultimately fatal
        • mostly due to uremia / hypertension
      • relatively stable
      • very slow progress
• Autosomal Recessive (Childhood) PKD
  • characteristics
    • autosomal recessive inheritance
    • 1/20000 live births
    • subcatergories
      • perinatal
      • neonatal
      • infantile
      • juvenile
    • PKHD1 gene - fibrocystin protien
      • chromosome 6p
  • morphology
    • numerous small cysts
    • spongelike appearance of kidney
    • there are cysts in the liver as well
  • clinical course
    • perinatal and neonatal forms
      • most common
    • serious manifestations at birth
      • die quickly
      • hepatic / renal failure
    • survivers develop liver cirrhosis
• Medullary Cystic Disease
  • characteristics
    • 2 major
      types
      • medullary sponge kidney
        nephronophthisis - medullary
        cystic disease complex
        • infantile
        • juvenile
          • most common
        • adolescent
        • adult
  • morphology
    • small contracted kidneys
    • numerous small cysts lined by flattened / cuboidal epithelium
  • clinical course
    • initial manifestation
      • polyuria
      • polydipsia
    • progression to End-Stage Renal Disease ensues over 5-10 years
    • difficult to diagnose
      • no serologic markers
      • cysts may be too small