Acquired renal cystic disease mimicking adult polycystic kidney disease in a patient undergoing long-term hemodialysis.

Acquired renal cystic disease (ARCD) is defined as the development of multiple cysts in the renal cortex and medulla in patients with chronic renal failure who are free from congenital polycystic kidney disease. ARCD develops generally in contracted kidneys. We report a case of grotesque enlargement of a single kidney in a patient who had been receiving hemodialysis for 18 years. Although the exact causes of ARCD are not known, 3 factors may contribute to the development of nephromegaly; the sex, the duration of hemodialysis and previous unilateral nephrectomy. As in polycystic disease, when the involved kidney reaches considerable size, ARCD may have a favorable effect on anemia caused by chronic renal failure.