Renal - Congenital and Cystic Kidney Disease (Pathoma)

CONGENITAL RENAL DISEASE
  • Most due to acquired gestational defect cf hereditary

Horseshoe kidney
  • Conjoined kidneys
  • Only "common" one - 1:750
  • Usually at inferior pole - 90%
  • Most common congenital renal defect
  • Located in lower abdo usually
    • gets hooked on inferior mesenteric artery when ascending 
  • Assoc
    • Turner syndrome (45,X ie 45,XO)
    • Edwards syndrome (trisomy 18)
    • Inc risk of
      • Wilm's
      • Obstruction and hydroneprhosis
      • Vesicoureteral reflux
      • Stones
      • Transitional cell carcinoma
Renal agenesis
  • Uni or bilateral
  • Absence of formation
  • Unilateral
    • Hypertrophy of contralateral
    • Does work of 2 kidneys
    • Gets hyper-filtration injury
      • Renal failure risk
      • Progessive glomerular sclerosis
      • Then CKD
  • Bilateral
    • Incompatible with life
    • Oligohydramnios
      • Baby not making urine so low amniotic fluid
      • Potter Sequence
        • Lung hypoplasia (baby should breathe fluid to build up and stretch lungs)
        • Flat face (squashed against uterus)
        • Low set ears 
        • Dev defects of extremities
Renal hypoplasia
  • Small
  • Most unliteral
  • If bi, renal failure as kid
  • Assoc
    • Low birth weight
    • Inc risk of future CKD
  • Unlike acquired ("shrunken kidney"):
    • NO scarring
    • Fewer renal lobes
    • Fewer pyramids (</=6)
Ectopic kidney
  • Pelvic brim or inside pelvis
  • Inc risk of obstruction, infection
CYST FORMING
  • Often due to ciliarly dysfunction
Dysplastic kidney
  • Non-inherited
  • Congenital malformation of renal parenchyma
    • Cysts
    • Abnormal tissue deposits - cartilage etc
  • Uni (most common) or bilateral
  • If bilateral, must distinguish between this and PKD
Polycystic kidney disease (PKD)
  • Inherited
  • Bilateral
  • Enlarged
  • Cysts in
    • Cortex
    • Medulla
  • 2 genotypes
  • Autosomal Recessive 
    • Infants
    • Worsening renal failure - childhood death
    • Increasing HTN
    • Genotype
      • PKHD1 mut - fibrocystin
    • Assoc
      • Potter Sequence - kidneys so bad that oligohydramnios
      • Congenital hepatic portal fibrosis
      • Hepatic cysts
        • Proliferating bile duts
    • (So if baby with portal HTN think AR PKD)
    • Gross
      • Enlarged, cystic kidneys at birth
        • Smooth outside
        • Cut surface cortical and medullary small cycsts- sponge
          
        • Histo - cylinders/sacs, cuboidal lining [made from collecting ducts]

  • Autosomal Dominant
    • Adults (young)
    • Common = 1:600
    • Bilateral
    • MutationTransitional cell carcinoma
      • PKD1 (polycystin-1, Chr16) or
      • PKD2 (polycystin-2, Chr4) - less severe
      • Seems to break pressure, Ca2+, signal sensing
    • Cysts develop over time - larger cf AR
    • Many oxalate crystals in urine
    • Present
      • HTN - increased renin
      • Haematuria
      • Worsening renal failure
        • Azotaemia
        • Eventually ureamia
      • aSx often
      • Sx
        • Draggin sensation
        • Abdo pain inc
    • Assoc
      • Berry aneurysms
      • Hepatic cysts - 40% - biliary epithelium
      • Mitral valve prolapse
    • Gross
      • Massive, bilateral
      • Externally covered in cysts
      • Fluid
        • Serous
        • Turbid red/brain
        • Haemorrhagic
    • Big cysts may go into calyces - pressure
    • Glomerular "tufts" if Bowman involved
Medullary Cystic Kidney Disease
  • Cysts in medullary collecting ducts
  • Parenchymal fibrosis
    • Shrunken kidneys
    • Worsening renal failure
  • 3 types
    • Innocuous
      • Medullary sponge kidney
        • Dilated papillary ducts, small cysts, cuboidal lining
        • No cortical scarring (unless pylonephritis etc)
    • Progessive
      • AR - Nephronopthisis - poss assoc with reintal disease
      • AD - Adult onset medullary cystic disease
      • @ Corticomedullary junction
Multicystic renal dysplasia
  • Uni or bi
  • Verry irreg
Acquired Dialysis Related Cystic Disease
  • Cortical and medullary
  • Due to stones/interstitial fibrosis
  • Haematuria
  • Inc RCC risk
Simple cysts
  • Cortical
  • Serous
  • Grey, smooth cuboidal membrane
  • SMOOTH
  • May haemorrhage into
Robbins Basic Pathology, Robbins Pathologic Basis of Disease, Robbins Review of Pathology (MCQs - very path-y), Robbins Flash Cards, Baby Robbins, Robbins Atlas - some exact same images come up in the exam, 100 Cases in ClinicalPathology - possibly the best Qbank for the practical