Comparative study of cystic variations of the kidneys in haemodialysis and continuous ambulatory peritoneal dialysis patients.

In recent years, many complications of renal cell carcinoma accompanying the increase in the number of peritoneal dialysis cases have been studied more often. Clinicopathologically, we studied comparatively cystic changes of the kidney, considered to be a background factor of cancerous development in 69 patients on peritoneal dialysis without past history of haemodialysis and in 192 patients on long-term haemodialysis. From the results, differences with respect to the duration of dialysis until the development of cysts and primary diseases commonly associated with cysts were not found between the two groups. Moreover, in the extirpated kidneys examined for cancerous development, cysts were found in both the peritoneal dialysis and the haemodialysis cases, and proliferative changes were found in the cystic epithelium. A relationship between cystic and cancerous development in the peritoneal dialysis cases was strongly suggested by these findings. Therefore, it was considered that careful follow-up studies for complications such as renal cell carcinoma would be necessary in both the peritoneal dialysis and the haemodialysis cases.