Definition, Etiology, PathogenesisTop
Acquired cystic kidney disease refers to the presence of ≥4 cysts involving both kidneys with atrophy and a reduction of overall kidney size after development of advanced chronic kidney disease (CKD). Acquired cystic kidney disease may develop regardless of CKD etiology and should not be confused with polycystic kidney disease. Acquired cystic kidney disease is common in patients undergoing renal replacement therapy, with incidence rising with dialysis vintage (length of time on dialysis). While etiology is unknown, proximal tubular cell proliferation is thought to be important. In the majority of cases cysts remain asymptomatic, but they may cause episodes of hematuria, chronic flank pain, or renal colic. Acquired cystic kidney disease is associated with risk of renal cell carcinoma, which may occur in 4% of patients. In 25% to 50% of renal cell carcinoma cases it is multifocal and bilateral.
Diagnosis is based on ultrasonography followed by computed tomography (CT) or magnetic resonance imaging (MRI) for questionable lesions. Screening would occur during evaluation for transplantation. Screening is not recommended in patients with limited life expectancy but can be considered in patients who have long life expectancies 3 to 5 years following the initiation of renal replacement therapy.
No specific treatment is required. Episodes of hematuria are treated symptomatically. Interventional radiologic or surgical treatment may be necessary in case of retroperitoneal bleeding from a cyst, persistent or severe hematuria, cyst infection not responding to medical treatment, and suspected or confirmed renal cell carcinoma.