Acquired cystic transformation of the kidneys of haemodialysed patients

Renal shear wave velocity by acoustic radiation force impulse did not reflect advanced renal impairment

AIM

Acoustic radiation force impulse is a noninvasive method for evaluating tissue elasticity on ultrasound. Renal shear wave velocity measured by this technique has not been fully investigated in patients with renal disease. The aim of the present study was to compare renal shear wave velocity in end-stage renal disease patients and that in patients without chronic kidney disease and to investigate influencing factors.

METHODS

Renal shear wave velocities were measured in 59 healthy young subjects (control group), 31 subjects without chronic kidney disease (non-CKD group), and 39 end-stage renal disease patients (ESRD group). Each measurement was performed 10 times at both kidneys, and the mean value of eight of 10 measurements, excluding the maximum and minimum values, was compared.

RESULTS

Renal shear wave velocity could be measured in all subjects. Renal shear wave velocity in the control group was higher than in the non-CKD group and in the ESRD group, and no difference was found between the non-CKD group and the ESRD group. Age and depth were negatively correlated to the renal shear wave velocity. In multiple regression analysis, age and depth were independent factors for renal shear wave velocity, while renal impairment was not. There was no difference between the non-CKD group and the ESRD group, even when ages were matched and depth was adjusted.

CONCLUSION

Renal shear wave velocity was not associated with advanced renal impairment. However, it reflected alteration of renal aging, and this technique may be useful to detect renal impairment in the earlier stages.

Role of magnetic resonance imaging in renal transplant recipients with acquired cystic kidney disease

OBJECTIVES

To evaluate the impact of magnetic resonance imaging (MRI) in renal transplant recipients whose ultrasound (US) examinations of the native kidneys have met the criteria of acquired cystic kidney disease (ACKD).

METHODS

The US scans of 840 renal allograft recipients were prospectively studied. In addition, 46 of 169 patients diagnosed with ACKD by US scans underwent MR examination. MRI protocols included (a) T1 and T2-weighted fast spin echo imaging, (b) T2-weighted gradient echo imaging, and (c) gadolinium-enhanced T1-weighted imaging in 7 patients with evidence of complex cysts. In the case of complex lesions, both US and MRI follow-up examinations were performed between 6 and 12 months after the prior examination.

RESULTS

US examination showed ACKD in 169 of 840 patients. In addition, US revealed 8 patients with renal cell carcinomas (RCC). Of these 8 patients, 7 had evidence of ACKD. The median number of cysts depicted on US examination in native kidneys of renal transplant recipients was 3 (range 0 to 10) on both sides. MRI revealed significantly more and smaller cysts compared to US. The median number of cysts was seven on the left and nine on the right native kidneys, respectively. MRI revealed 18 complex lesions in 7 patients. Thirteen of 18 complex lesions were undetected by US.

CONCLUSIONS

MRI is superior to US in depiction of simple and complex lesions of native kidneys in renal allograft recipients. MRI exhibits no overestimation of the prevalence of ACKD on the basis of the US criteria already mentioned. Advantages of MRI do not justify routine screening tests by this imaging modality. However, MRI should be used for further evaluation of complex lesions detected by US.

Enhanced neoplastic lesion development with adenine-induced experimental multicystic nephropathy by adenine--a model system for the analysis of renal tumor generation in long-term hemodialysis patients

To cast light on the high incidence of renal cell tumors (RCT) in long-term hemodialysis patients, the role of background multicystic nephropathy was studied in a rat model. Group 1 animals were initially given N-ethyl-N-hydroryethylnitrosamine (EHEN) then subjected to adenine feeding until killing during weeks 20-27. Groups 2 and 3 received EHEN and adenine, respectively. All rats receiving adenine developed multicystic nephropathy. The incidence of renal cell hyperplasias (RCH) and multiplicities of both RCH and RCT in Group 1 were significantly increased as compared with Group 2, suggesting multicystic nephropathy provides favorable environment for tumor development.

Acquired cystic disease and renal adenocarcinoma following renal transplantation

Acquired renal cystic disease has been associated with the development of renal cell carcinoma in patients on chronic dialysis. The disease has been documented to regress in the native kidney after successful renal transplantation. We report 4 cases of renal cell carcinoma occurring in the native kidney 3 to 8 years after successful renal transplantation. Of these patients 3 also had acquired cystic disease of the native kidney. These 3 cases suggest that the malignant potential associated with acquired renal cystic disease may not be reduced significantly by renal transplantation and that periodic imaging of the native kidney is advisable after transplantation, particularly when the disease is present before transplantation.

Renal cell adenomas and carcinomas in hemodialysis patients: relationship between hemodialysis period and development of lesions

Step-sections of 96 whole kidneys from 50 chronic hemodialysis patients were subjected to a histopathological and quantitative investigation with regard to the development of renal neoplastic lesions. The range of hemodialysis duration was from 1 to 222 months. A total of 349 renal cell adenomas were found in 41 cases (82%). They were commonly multiple and present bilaterally. Renal cell carcinomas were evident in four cases (8%), with hemodialysis durations of 54, 57, 112 and 222 months. The incidence of adenomas increased in a hemodialysis duration-dependent manner, indicating a high risk of renal cell tumor development in chronic hemodialysis patients. Furthermore, acquired cystic disease of the kidney (ACDK) was also observed in 12 cases (24.0%), where the mean hemodialysis period was 143.4 +/- 48.0 months. This value was significantly longer than that of non-ACDK cases (P < 0.001). There was, however, no clear relationship between the appearance of ACDK and renal cell tumors. The present results underline the necessity for attention to possible neoplasia of the kidney in patients on long-term hemodialysis.

Metastatic renal cell carcinoma associated with acquired cystic kidney disease 15 years after successful renal transplantation

Renal cell carcinoma (RCC) is a relatively uncommon cancer in renal transplant patients. From 1968 to 1987, 101 cases of RCC of native kidneys have been reported to the Cincinnati Transplant Tumor Registry. We describe here a case of metastatic RCC associated with acquired cystic kidney disease (ACKD) 15 years after successful renal transplantation. The patient presented with a subcutaneous nodule, which led to discovery of a large primary tumor in the left kidney. ACKD was present in the atrophic right kidney. The reported cases of ACKD-associated RCC in renal transplant recipients were reviewed. Most of these cases are middle-aged men with a long posttransplant course, good graft function, and usage of azathioprine and prednisone as immunosuppressive agents. ACKD can develop or persist and progress to RCC many years after successful renal transplantation. Transplant patients with flank pain, hematuria, or other suspicious symptoms should have imaging studies of their native kidneys.

Renal cell carcinoma

Renal cell carcinoma accounts for 3% of all adult cancers and has many unusual features in its presentation, diagnosis, and management. It develops in a significant number of patients with acquired renal cystic disease, a disorder found almost exclusively in chronic hemodialysis patients. Abnormalities of chromosome 3 are frequently found in sporadic and familial forms. Radical nephrectomy remains the only potentially curative therapy for this tumor.

End stage renal disease serum contains a specific renal cell growth factor

End stage renal disease (ESRD) kidneys display abnormal growth characterized by a continuum of cystic disease, adenoma and carcinoma. This study evaluates the hypothesis that serum of patients with ESRD contains increased amounts of a growth factor which specifically induces proliferation of renal cells. ESRD sera compared to sera from normal controls induced a two to three-fold increase in the proliferative rate of renal cell carcinoma cell lines and normal kidney explants compared to cell lines from other sites. The increased proliferative activity of ESRD sera on renal cells was paralleled by an increase in cytosolic free calcium. The growth factor activity was encoded by a polypeptide of between 15 and 30 kd. The activity of ESRD sera on renal cells was not mimicked or inhibited by epidermal growth factor, basic fibroblast growth factor and platelet derived growth factor indicating that the renal cell specific growth factor activity in ESRD is different from these factors.

Clinicopathological study of kidneys from patients on chronic dialysis

Kidneys removed from 58 pediatric patients at renal transplantation (except 3 cases), who had developed chronic renal failure and were maintained on dialysis, were investigated histopathologically, and the clinical profiles were taken into account. The patients ranged in age from 2 to 24 years, with an average of 11.2 years. The duration of dialysis ranged from 0.5 to 63 months, with an average of 12.6 months. The kidneys, which were conventionally prepared for histological observation, were subjectively divided into three groups depending on the degree of remaining nephrons. Patients with completely atrophic type (type 1), incompletely atrophic type (type 2), and mixed type of atrophy and hypertrophy (type 3) had a duration of dialysis of 20.0, 12.3, 6.3 months, respectively (Type 1 greater than Type 3, P less than 0.01). A correlation between histology and function was demonstrated, since urinary output was more than 200 ml/day in most of the type 3 patients, and less than 20 ml/day in all of the patients with type 1. The findings suggest that the functioning nephrons that remained at the beginning of dialysis generally become atrophic within one year after the initiation of dialysis. The ratio of kidney weight to body weight showed a significant negative correlation with both the duration of dialysis and that of illness. The histopathological changes seen in kidneys of patients on dialysis were reviewed. The findings suggested that certain changes, unusual epithelial proliferations an oxalate deposition, are associated with persisting renal function rather than the duration of dialysis.

The role of ischemia in acquired cystic kidney disease

Acquired cystic kidney disease (ACKD) is the result of cyst formation in failing noncystic kidneys. This condition occurs in patients with chronic renal failure and becomes more common with increasing time on renal replacement therapy. Its complications include hemorrhage and tumor formation, which have acquired greater significance as more patients are started on dialysis treatment. The causes of ACKD remain speculative thus far. Its occurrence in nondialyzed patients suggests that dialysis itself is not a necessary factor in its pathogenesis. Five cases of severe unilateral renovascular disease and associated cyst formation are reported. The authors conclude that ACKD may derive from primary renovascular occlusion or from the secondary arterial and arteriolar occlusions seen in the end-stage kidney.

An autopsy case of interlobar arterial dissection of the kidney following long-term hemodialysis

An autopsy case of massive renal hemorrhage in a 49-year-old male who had undergone maintenance hemodialysis for 8 years, is reported. No bleeding tendency had been noticed, and blood pressure had been reduced to within the normal range. Histological investigation with semiserial sections revealed that hemorrhage had occurred in four arteries, corresponding to the interlobar, arcuate, and interlobular levels, which existed in the same ruptured cyst wall. Acute dissection had occurred in two of the four arteries, leading to rupture of the cyst; this led to destruction of the remaining arteries. Both kidneys, which were markedly shrunken and had numerous cysts in the cortex and medulla, fell into the category of acquired cystic renal disease of long-term hemodialysis. It was suspected that renal vascular change during hemodialysis, mechanical factors compressing the protruding artery in the cyst with scanty renal interstitium, and relatively radical hemodynamic changes during dialysis had contributed to the hemorrhage.

Effects of chronic phthalate exposure on the kidney

Several investigators have reported the finding of polycystic kidney disease (PKD) at autopsy in patients who had undergone long-term hemodialysis for renal failure due to causes other than PKD. We initiated studies to determine whether the drugs or chemicals to which patients on dialysis are exposed could be responsible for these cystic changes. Adult rats were tube fed chemical residues from an artificial kidney or phthalate esters [di(2-ethylhexyl) phthalate, DEHP], which are a main component of these plastic kidneys or a control solution. Rats receiving DEHP or residues showed a significantly higher incidence of focal cysts when compared to controls. Rats receiving DEHP developed a significant decrease in kidney function as demonstrated by creatinine clearance, and these animals had the highest tissue levels of measureable DEHP. We postulate that patients receiving long-term dialysis may acquire PKD secondary to their exposure to chemicals leached from artificial kidneys.

Acquired cystic kidney disease in children undergoing long-term dialysis

Acquired cystic kidney disease (ACKD) occurs in adult patients undergoing long-term dialysis. Early detection is important because clinically significant hematuria and malignancies are associated with ACKD. We evaluated by magnetic resonance imaging (MRI) and ultrasonography (US) the incidence of ACKD in 15 patients aged 7.3-21.6 years (mean 15.9 years) with non-cystic primary renal disease. Nine patients had been treated with peritoneal dialysis only, and 6 with both hemodialysis and peritoneal dialysis for 24-73 months (mean 37 months). Three patients (20%) had no cysts. In 5 patients (33%) with bilateral multiple cysts, the diagnosis of ACKD was made by MRI and US. In another 5 patients, solitary cysts were localized to one kidney by MRI, and in 2 patients solitary cysts were seen in both kidneys. This study documents that ACKD is not limited to older patients with end-stage renal disease. Early detection of these cysts can be accomplished by MRI and is warranted since 1 patient developed neoplastic tubular changes which can precede tumor formation.

Renal adenocarcinoma and end stage kidney disease

The association of end stage kidney disease with cystic degeneration and renal adenocarcinoma was first recognized in 1977. Since then a number of reports have confirmed this relationship. Duration of dialysis has been the most strongly associated risk factor. We report 8 cases of end stage kidney disease and renal adenocarcinoma. Median duration of hemodialysis was approximately 1 year, and 3 patients never had hemodialysis. Factors other than duration of dialysis, such as toxic metabolites, toxins from dialysis tubing, polyamines or other carcinogens, may be as or more important.

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.

Renal adenocarcinoma and acquired cystic disease in chronic hemodialysis patients

Three chronic hemodialysis patients developed renal cell adenocarcinoma with evidence of acquired cystic disease in two. The incidence of renal cancer in this study population of 0.27% per year is 50 times greater than that expected in general. The cancers appeared to develop at different rates. In one patient examined by serial computed tomography (CT) over 2.5 years, the tumor progressed rapidly. In the other two patients, the process was more idolent. On the basis of our experience, we recommend that dialysis patients be screened for acquired cystic kidney disease (ACKD) and renal tumors by sonography or CT. Patients with ACKD should be observed at regular intervals by CT for the development of possible tumor.

Renal epithelial hyperplastic and neoplastic proliferation in autosomal dominant polycystic kidney disease

The early v late occurrence of tubular epithelial hyperplasia and the frequency and malignant potential of renal neoplasms in autosomal dominant polycystic kidney disease (ADPKD) are controversial. The kidneys from 87 patients with documented or presumed ADPKD, removed at autopsy (n = 49) or prior to transplantation (n = 38), were thoroughly sectioned and examined. Hyperplastic polyps were found in 90.8% of the patients, even in the absence of renal insufficiency or marked renal enlargement. However, their number was significantly higher in the patients with advanced stages of the disease, and especially in those with a history of dialysis. Hyperplastic polyps were not detected in eight cases, seven of which had no evidence of epithelial hyperplasia, despite thorough examination of multiple sections. A total of 42 neoplasms were observed in 24.1% of the patients. One patient had bilateral low-grade clear cell adenocarcinoma. Another patient had a transitional cell neoplasm. The remaining 39 neoplasms were microscopic adenomas. Neoplasms tended to occur more often in men and older patients. None of these neoplasms had been clinically diagnosed, and no metastasis had occurred. Nonneoplastic mass lesions were observed in two patients: one had malacoplakia and the other had xanthogranulomatous pyelonephritis.

Clinical characteristics and diagnostic considerations in acquired renal cystic disease

Acquired multiple bilateral cystic transformation of kidneys has been increasingly noted in patients with long-standing renal failure treated by chronic dialysis. To study the clinical characteristics of this newly described disease and assess the utility of available diagnostic methods, 130 patients with chronic renal failure (100 on dialysis, 30 nondialyzed) were studied with ultrasonography and/or computerized tomography (CT). Among patients on dialysis, 22% had acquired renal cystic disease (ARCD), an additional 30% had one to three solitary cysts, and 48% had no cysts. In nondialyzed patients, 7% had ARCD, 53% had one to three solitary cysts, and 40% had no cysts. Among these 130 chronic renal failure patients (nondialyzed and dialyzed), 21 of 86 males compared to 1 of 44 females had ARCD (P less than 0.001). Duration of dialysis therapy and age were greater in patients with ARCD (49.8 +/- 8 months, 55 +/- 4 years, respectively) compared to those with solitary cysts (28 +/- 6 months, 45 +/- 2 years) or no cysts (15 +/- 3 months, 42 +/- 2 years). The diagnostic accuracy of ultrasound (US) was compared to CT. CT is purportedly 100% accurate in the characterization of renal cysts. We are disappointed at the low level of diagnostic accuracy for both CT and US in the detection of renal cysts in chronic uremia. It appears both a negative CT and ultrasound are necessary to absolutely exclude either ARCD or solitary cyst.

Chronic renal failure: a significant risk factor in the development of acquired renal cysts and renal cell carcinoma. Case reports and review of the literature

Three male patients with end-stage renal disease on chronic hemodialysis presented with gross hematuria and were subsequently found to have acquired renal cyst disease and progressive bilateral renal cell carcinoma. There are now more than 84 similar cases in the literature, but the precise roles that renal failure and hemodialysis play in the development of renal cysts and renal neoplasms remain unclear. The high incidence of acquired renal cyst disease (45%) and the development of renal tumors (9%, with a 5% to 7% metastatic rate) in patients with end-stage renal failure clearly underscores the need for more intense radiologic monitoring.

The natural history of simple renal cysts: a preliminary study

We examined the natural history of simple renal cysts in 59 patients followed periodically with renal ultrasonography. Using the parameters of cyst diameter and number we grouped the patients according to the differing natural history of the cystic lesions. The results indicate that simple cysts tend to progress in number rather than size. Furthermore, 3 patients had independent solid or complex lesions. The only patient explored had an adenocarcinoma of the kidney. Periodic reevaluation of patients with an ultrasonic diagnosis of simple renal cyst warrants serious consideration.

Spontaneous renal subcapsular hematoma in a patient undergoing hemodialysis

We describe a patient on hemodialysis in whom a spontaneous renal subcapsular hematoma developed. The diagnosis was confirmed by computerized tomography and angiography, and the patient was treated conservatively. We recommend conservative management in such cases based on radiological findings that rule out underlying pathological changes.

Acquired cystic disease of the end-stage kidney

The development of multiple cysts in the previously noncystic chronically diseased kidneys of patients undergoing long-term dialysis appears to be associated with spontaneous renal bleeding and benign and malignant renal tumors. Two cases of acquired cystic disease with renal hemorrhage and adenocarcinoma are presented; metastases occurred in one patient and the other had bilateral carcinoma requiring bilateral nephrectomy. Combined data from 13 studies indicate acquired cystic disease occurs in one third of patients undergoing maintenance hemodialysis and is associated with adenocarcinoma in 4 percent of cases. Four cases of metastases and five deaths linked to acquired cystic disease have been reported. Eight of 24 patients with acquired cystic disease and clinical manifestations of renal bleeding had renal adenocarcinoma. Autopsy series indicate tumors associated with acquired cystic disease are usually benign but commonly bilateral and multiple. Cystic transformation of the end-stage kidney is more frequent after several years of hemodialysis. It is suggested that patients receiving dialysis treatments for more than three years have a baseline radiologic examination of the kidneys so that subsequent problems can be more easily identified and evaluated.

Uremic acquired cystic disease of kidney

Multiple cystic disease occurring in the diseased kidneys of patients with end-stage renal insufficiency is called uremic acquired cystic disease of the kidney. In male patients undergoing long-term hemodialysis the incidence of ACDK is markedly high. ACDK is known to be accompanied by tumor, bleeding, calculus, abscess, etc., and the complication of cancer of the kidney is a special problem. In patients undergoing hemodialysis, occurrence of ACDK, tumor, and kidney cancer are observed respectively at the rate of 47.1, 4.8, and 1.5 per cent. When hemodialysis patients show gross hematuria, flank pain, rapid decrease in hematocrit, and sustained fever, ACDK or its complications should be investigated. Since the risk accompanied by kidney cancer is high in spite of a lack of symptoms, regular screening by ultrasonic examination or CT scan is needed. Renal transplantation is also recommended because of the regression of ACDK after successful renal transplantation. In the future, it appears that ACDK should be considered one disease entity and added to the categories of renal cystic diseases. In addition, ACDK can be studied as a model for clarification of the mechanism of cyst and tumor occurrence.

Cystic kidneys: an enigma evolves

Substantial contributions to the field of RCD have been made over the past 15 years. Most intriguing is a growing awareness of acquired RCD and its complications. Data have been published and are reviewed here in support of a possibility that APKD and RCD acquired during hemodialysis are premalignant lesions. More data are needed before the possibility can be confirmed or denied. The collection of these data is an immediate need in the field of RCD.

Clinical importance of acquired cystic disease of the kidney in patients undergoing dialysis

From 1976 to 1982 five patients undergoing haemodialysis at Oxford Renal Unit suffered serious complications from acquired cystic disease of the kidney and two died as a direct result. Clinical features seen were pain, haematuria, palpable renal enlargement, massive haemorrhage, resolution of anaemia, and metastatic malignancy. The clinical histories emphasise the features of a disease that is likely to assume increasing importance in patients undergoing haemodialysis.

Confirmation of the development of multiple renal cell tumors in endstage/long-term hemodialysis kidney revealed typical acquired cystic transformation

Histopathological study of the endstage kidney in a 50-year-old male who died after intermittent maintainance hemodialysis for 10 years was reported. At autopsy, both kidneys were contracted and characterized by grossly visible discrete multiple cysts. Histopathological study of consecutive sections of both kidneys revealed that these cysts were distributed throughout a completely disorganized parenchyma and were composed of dysplastic epithelial cells of different types and of structures, some of which revealed neoplastic transformation.