Natural history of acquired renal cystic disease in dialysis patients: a prospective longitudinal CT study.

Patients with end-stage kidney disease, particularly those treated with dialysis, develop proliferative processes in their native kidneys that result in the formation of multiple acquired renal cysts, renal adenomas, and carcinomas. Data about these abnormalities have been acquired mainly from retrospective studies. We undertook a longitudinal prospective study in which the native kidneys of 30 dialysis patients were surveyed by serial CT during a 7-year period to study the natural history of acquired renal cystic disease and the frequency of associated complications. Acquired cysts were seen in 87% of patients at the end of the study compared with 57% at the study's onset, and a significant increase was seen in mean renal volume with time. Five patients (17%) developed large hemorrhagic renal cysts and four (13%) developed large perinephric hematomas. Renal cell carcinomas developed in two patients (7%) without renal symptoms. One carcinoma invaded the renal capsule, but did not cause metastases. The other carcinoma was widely metastatic. Our findings are consistent with those of earlier studies documenting an increased prevalence of renal cell carcinoma in dialysis patients as compared with the general population. However, our conclusions are limited because the study sample is small and no control population was studied. We conclude that acquired renal cystic disease in dialysis patients is a progressive disorder often associated with cyst hemorrhage. Dialysis patients may also have an increased prevalence of renal cell carcinoma.