American Urological Association - Acquired Cystic Disease
Acquired Cystic Disease
- Development of multiple (>3) and bilateral renal cysts in patients whose CRF cannot be attributed to hereditary cystic disease.
- >50% patients on dialysis for more than 4 years.
- More common in males and African-American than Caucasian.
- Clinical: Bilateral and asymptomatic in its early stages; cysts are present in 8% of patients at initiation of dialysis; 90% develop cysts after 10 years of dialysis.
- Some cysts develop before dialysis, suggesting it's not only due to dialysis.
- Mostly asymptomatic, some may present with abdominal pain and hematuria.
- Shrunken kidneys.
- Cysts range from 0.5 - 3 cm in diameter.
- Initially cortical in location, later medullary region too (image A).
- Tubular cysts in medulla and cortex.
- Cysts are lined by flattened cuboidal or columnar epithelium (image B).
- Generally involve the proximal tubules of the kidney.
- May have calcium oxalate crystal depositions.
- Occasional cysts contain clear cells that are carbonic anhydrase IX+; may be a precursor of RCC.
- Should be accompanied by other changes of dialysis (end-stage) kidneys (sclerosis, fibrosis, atrophy, etc.).
- Complications: RCC (50-100X increased risk), intrarenal and retroperitoneal hemorrhage and cyst infection.
- 2-7% developed RCC, which include some unusual form (ACD-associated RCC and clear cell papillary RCC).
- Large cysts require surgery to exclude RCC.