What is acquired renal cystic disease (ARCD)?
ARCD is a noninherited condition characterized by multiple small cysts (three or more per kidney) filled with serous fluid distributed throughout the renal parenchyma of patients with ESKD. Therefore family and clinical history are often helpful for distinguishing ARCD from ADPKD. The prevalence of ARCD varies as a function of serum creatinine levels, being 7% to 22% in patients with CKD and serum creatinine greater than 3 mg/dL, 35% in patients with less than 2 years of dialysis, 58% with 2 to 4 years, 75% with 4 to 8 years, and 92% in those undergoing dialysis for 8 or more years.
ARCD usually affects both kidneys equally, and the affected kidneys are typically small (<100 g), although a few exceptional cases may growth resembling ADPKD. Most patients with ARCD are asymptomatic, but hemorrhage may occur. Cysts often regress after kidney transplantation but may occasionally develop in chronically rejected kidneys. Importantly, patients with ESKD and ARCD have 50-times higher risk of developing RCC during dialysis or after kidney transplantation compared with the general population. Risk factors for coexisting ARCD and RCC in ESKD patients include uremic toxins (p-cresol), ischemia, viral infections, tubular obstruction, and increased secretion of parathyroid hormone and growth factors. Carcinomas in patients undergoing dialysis are three times more common in the presence than in the absence of ARCD, and it is six times more common in large cystic kidneys than in small cystic kidneys. Therefore ultrasonography or MRI screening has been recommended after 3 years of dialysis, followed by screening for neoplasm at 1- or 2-year intervals thereafter.
