Acquired cystic kidney disease

Acquired cystic kidney disease (ACKD) is a condition that occurs in patients with end-stage renal disease (ESRD), especially when on dialysis treatment. They do not have a history of other cystic renal disease.

Epidemiology

Its incidence increases with the amount of time a patient is azotemic and has been estimated at 44% after three years of dialysis and 90% after ten years of dialysis . It is equally common with haemodialysis as with peritoneal dialysis .

Clinical presentation

Usually asymptomatic. Cyst hemorrhage may cause flank pain and hematuria .

Pathology

Although uremia is associated with an eventual development of acquired cystic kidney disease, the pathogenesis is currently unknown. Some theories suggest that tubular epithelial hyperplasia from accumulation of growth factors, such as epidermal growth factor may play a role .

The hyperplastic renal cysts in ACKD have been considered a possible source of dialysis-associated renal cell carcinoma .

Radiographic features

The classic imaging appearance is multiple bilateral small renal cysts, occurring in both the cortex and medulla, with both kidneys typically small in size (refer to the chronic kidney disease (CKD) article for a broad discussion on the condition's correlated imaging findings).

Diagnostic criteria include:

• patients with chronic renal failure
  • kidneys usually decreased in size
• >3-5 cysts in each kidney
• cysts are mostly cortical, but may also be medullary

Treatment and prognosis

Renal transplantation has been thought to resolve acquired renal cysts, but there is still a risk of renal cell carcinoma in the native kidneys.

Complications

• hemorrhage into cysts, which occurs occasionally
• development of renal cell carcinoma in ~7% 
  • imaging screening for these patients is controversial
    • one screening strategy images patients <55 years old who have been on dialysis for three years

History and etymology

ACKD was first described in 1977 by MS Dunnil et al. .