Acquired multicystic transformation of kidneys

Acquired Renal Cystic Disease and Its Complications in Continuous Ambulatory Peritoneal Dialysis Patients

Purpose

To determine whether there is any difference in the prevalence of acquired cystic disease and malignancy of the kidney in patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis.

Data Identification

Relevant studies published from January 1983 to June 1991 were identified by manual search and MEDLINE search.

Study Selection

We reviewed the studies in which acquired renal cystic disease and/or renal cell carcinoma developed in patients on CAPD.

Data Extraction

Details of the prevalence of acquired cystic disease and renal malignancy as a complication of acquired cysts in CAPD patients were tabulated with the duration of treatment.

Results

Acquired cystic disease was observed in 195 of 425CAPD patients(41.1%), which is comparable to the prevalence of 47.1% (520/1103) seen in hemodialysis patients. The overall prevalence of renal cell carcinoma accompanying acquired cystic disease in this series of CAPD patients was 2 of 375 (0.4%), which is comparable to the prevalence of 1.5% (17/1103) in hemodialysis patients. So far, eight other instances of renal cell carcinoma complicating acquired cystic disease in CAPD patients were described as case reports. Retroperitoneal bleeding due to the rupture of acquired cysts has been reported on a few occasions.

Conclusion

In this review no differences were detected in the prevalence or severity of acquired renal cystic disease in patients treated with CAPD as compared with those on hemodialysis. Therefore, the incidence of complications associated with acquired cysts may also be the same for the two treatment modalities, although reports on such complications are rare.

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.

Renal neoplasm in acquired cystic kidney disease

The development of renal cell neoplasms ranging from adenoma to metastatic carcinoma is the most serious complication of acquired cystic kidney disease (ACKD). A comprehensive review of the pertinent literature shows that there is up to 50-fold increased risk of renal cell carcinoma in ACKD compared to the general population. The ACKD-associated renal cell carcinoma is seen predominantly in males, occurs approximately 20 years earlier than in the general population, and is frequently bilateral (9%) and multicentric (50%). Acquired cystic kidney disease-associated renal cell carcinoma is frequently asymptomatic (86%), but may be associated with bleeding, abrupt changes in hematocrit, fever, and flank pain or rarely with hypoglycemia, hypercalcemia, or metastases at presentation. Computed tomography seems to provide a better diagnostic yield than sonography or magnetic resonance imaging; nevertheless, large (up to 8 cm) tumors not visualized by any imaging techniques have been reported. It is generally agreed that there is a need for regular screening of symptomatic ACKD patients for early detection of renal cell carcinoma; however, whether screening is needed for asymptomatic patients remains controversial. Nephrectomy is indicated for tumors larger than 3 cm. Management for tumors smaller than 3 cm with persistent symptoms, such as back pain or hematuria, remains controversial, but nephrectomy may be recommended since many of these tumors turn out to be unequivocal renal cell carcinoma. Asymptomatic tumors smaller than 3 cm should be serially screened, and tumor enlargement may be an indication for nephrectomy. Acquired cystic kidney disease-associated renal cell carcinoma accounts for approximately 2% of deaths in renal transplant patients. A median length of survival of approximately 14 months and a 5-year survival rate of 35% are comparable to the same data for renal cell carcinoma in the general population. Successful renal transplant probably decreases the risk of renal cell carcinoma in ACKD patients, but this preliminary observation needs confirmation. The development of ACKD-associated renal carcinoma is a continuous process with evolving phenotypic expression, including damaged renal tubule, simple cyst, cyst with atypical lining, adenoma, and, finally, carcinoma. The pathogenesis of this continuous process is not entirely known, but growth factor-induced compensatory growth of tubular epithelium initiated by the changes of end-stage kidney disease, and probably perpetuated by activation of proto-oncogenes, seems to be the most significant factor.

Acquired cystic disease of the kidney in association with chronic ambulatory peritoneal dialysis

A combined necropsy and ultrasound study in patients with end-stage renal disease treated exclusively by peritoneal dialysis revealed acquired cystic disease of the kidney (ACDK) in five of 15 necropsies and in one of seven sonograms from living patients. Two benign microscopic adenomas were also found in the first group of patients. No malignant renal tumors or hemorrhagic complications were detected. The cause of the cyst formation is clearly related to chronic renal failure rather than dialysis per se, as one patient had cysts prior to CAPD and seven of 41 patients with end-stage renal disease in the predialysis era were found to have renal cysts on postmortem examination. This study shows that ACDK is not uncommon in patients with chronic renal failure treated by chronic ambulatory peritoneal dialysis.