15- CYSTIC RENAL DISEASE

• Types of cystic renal disease


  • Acquired:
  • Simple cyst
  • Acquired cystic disease of CKD
  • Renal carcinoma
  • Hereditary:
  • ADPKD
  • ARPKD
  • Von Hipple Lindau
  • Tuberous sclerosis
• Pediatric onset vs adult onset cystic renal disease


  • Pediatric Onset
  • Adult Onset
• Pediatric onset cystic renal diseases


  • ARPKD
  • Nephronophthisis
  • Multicystic Renal Dysplasia
• Adult onset cystic renal diseases


  • ADPKD
  • Medullary Sponge Kidney
  • Medullary Cystic Disease
• Renal cysts are common particularly with advancing age (50% of people over the age of 50 years)
• Renal cysts can be single or multiple
• Renal cysts are usually benign, asymptomatic, and discovered incidentally on abdominal US or other imaging study
• Occasionally renal cysts cause pain and/or hematuria
• The primary clinical concern is accurately distinguishing simple from complex renal cysts that are associated with an increased risk of malignancy
• No treatment is necessary in most cases of renal cysts
• Simple renal cyst


  • Well defined outline
  • Homogenous content
  • Absent calcification
  • Minimal change in size
  • No enhancement with contrast
• Malignant renal cyst


  • Irregular outline
  • Heterogenous content with thick septa
  • Present calcification
  • Enlarge with time
  • Enhance with contrast
• Polycystic renal disease


  Can be inherited as an autosomal dominant (Adult polycystic kidney disease) or autosomal recessive (previously called infantile polycystic kidney disease)
• Type


  • Adult (ADPKD)
  • Infantile (ARPKD)
• Inheritance


  • adult: Autosomal dominant (the most common genetic cause of chronic kidney disease)
  • infant: Autosomal recessive
• Incidence


  • Adult: 1:1000
  • Infantile: 1:20,000
• Genetics (adult)


  • Chromosome 16 p (most cases): mutation in PKD1 gene which encodes for protein polycystin 1, an integral membrane protein that regulates tubular and vascular development in kidneys and other organs
  • Chromosome 4: mutation in the PKD2 gene
  • Chromosome 6
• Age of presentation


  • 30s-50s
  • Perinatal
• Pattern of presentation (Adult)


  • Hypertension (> 50% of cases)
  • Hematuria
  • Acute loin pain (due to hemorrhage, infection, or stone formation especially uric acid stones)
  • Abdominal discomfort (due to enlargement)
• Pattern of presentation (Infantile)


  • Oligohydramnios (it indicates severe disease and may lead to potter syndrome)
  • Large liver and kidney
  • Chronic renal failure
• Liver involvement (Adult)


  • Adult liver cysts are common à hepatomegaly
• Liver involvement (Infantile)


  • Always congenital hepatic fibrosis
  • Sometimes biliary ectasia
  • Complications: portal hypertension & cholangitis
• Other systemic involvement (Adult) Adult * (ADPKD)


  • Intracranial aneurysms (5-20% -most do not rupture but it may lead to subarachnoid hemorrhage) à screening is ONLY indicated if positive family history
  • Diverticulosis (not polyps)
  • Mitral valve prolapse (20%)
  • Hernia (abdominal or inguinal)
  • Rarely: cysts in pancreas, spleen, brain, ovaries and other organs
• Other systemic involvement (Infantile) (ARPKD)


  • Usually none; however, there may be pulmonary insufficiency secondary to pulmonary hypoplasia and enlarged kidneys limiting diaphragmatic movement which may be severe (Pulmonary complications are the leading cause of morbidity and mortality in neonatal period)
• Prognosis


  Often require dialysis but good
• End-stage renal failure (most common cause of death)

  • Develops in about 50% of patients by 50-60 years of age as a result of recurrent episodes of pyelonephritis and nephrolithiasis
• All die by age 20


  • Often in neonatal period
• Medullary sponge kidney


  Uncommon condition characterized by dilatation of the collecting ducts in the papillae, sometimes with cystic changes
• Medullary sponge kidney


  • Thought to be associated with hyperparathyroidism and parathyroid adenoma and in 20% of the patients there is hypercalciuria or renal acidosis