[A study of the native kidneys in patients with chronic renal failure. Report 2: Correlation between cystic changes in native kidneys and development of renal tumor].

The factors which made acquired cysts develop to renal tumors in chronic hemodialysis patients was investigated from clinical and histological findings. Although three renal tumors were found among 151 patients with chronic renal failure, clinically, one case had acquired cystic disease of the kidneys (ACDK), one case had simple cysts and the other case did not have any cyst. However, the last two cases had multiple small cysts histologically. In ACDK, renal tubules were degenerated and dilated, fused to each other, forming more larger cysts. Furthermore, epithelium of acquired cysts showed columer and dysplastic change, and papillary adenomas were developed into the inner space of the cyst wall. And ACDK kidney without renal tumor also revealed the same findings in histological examinations. It was postulated that renal tumor occurred from the papillary projections of the dysplastic epithelium of cysts. Therefore cysts in uremic patients seemed to be different from the simple cyst in normally functioning kidneys.