Renal cell carcinoma of native kidneys in renal transplant recipients

Detection and Characterization of Atypical Renal Cysts and Solid Renal Masses in Kidney Transplant Patients by Use of Dual-Energy CT Iodine Maps

OBJECTIVE. The purpose of this study was to evaluate whether dual-energy CT follow-up of kidney transplant recipients performed with only two contrast-enhanced phases and reconstructed material maps has the same diagnostic efficiency as triphasic conventional CT in detection and characterization of atypical renal cysts and renal masses. MATERIALS AND METHODS. In a retrospective study, 175 renal transplant patients underwent dual-energy CT as part of their follow-up (monoenergetic unenhanced, late contrast-enhanced, and tubular contrast-enhanced dual-energy phases). An unenhanced virtual series and material separation maps were reconstructed. ROIs were marked on theses lesions, the bladder, and the psoas muscle. Material suppressed iodine was used to record attenuation measurements on the unenhanced and virtual unenhanced series in the tubular and late phases, and material concentration measurements were obtained on the iodine density images. The delivered doses for each series were registered. RESULTS. One hundred one renal lesions (spontaneous attenuation > 20 HU, size > 10 mm) were detected. An iodine concentration threshold greater than 1500 μg/mL was associated with excellent diagnostic performance (sensitivity, 100%; specificity, 92.55%; positive predictive value, 50%; negative predictive value, 100%) for detection of suspect lesions (enhancement > 20 HU). The two lesions with an iodine concentration greater than 5000 μg/mL corresponded to the only two histologically proven cancers. CONCLUSION. Iodine concentration maps obtained with dual-energy CT perform as well as enhanced images obtained at conventional CT in the detection and characterization of tissue and atypical cystic renal lesions in kidney transplant recipients. Use of this method could reduce radiation dose, especially by avoiding the unenhanced series.

Two papillary renal cell carcinomas of different origin following renal transplantation (Case report)

Papillary renal cell carcinoma (PRCC) is a rare malignant tumor entity compared to common clear cell renal carcinoma. In the present study, we report a patient who was diagnosed with PRCC twice and successfully treated each time following renal transplantation. The first PRCC was located in the left native kidney two years following transplantation, and the second PRCC was diagnosed in the allograft 13 years following transplantation. The two tumors were completely removed by surgery in stage I of the disease with sufficient conservation of the allograft function. Notably, the tumors had a different origin as indicated by the microsatellite analysis, which reflects the exceptional course of the case. Risk factors for PRCC were identified in our patient. We concluded that high-risk candidates for malignancies in renal transplant recipients should receive shorter ultrasonic screening intervals, which may facilitate early tumor detection and improve outcome rates.

De novo renal tumors arising in kidney transplants: midterm outcome after percutaneous thermal ablation

PURPOSE

To retrospectively evaluate the midterm outcome of patients treated for primary renal cell carcinomas arising in kidney transplants with minimally invasive techniques.

MATERIALS AND METHODS

The institutional review board of each participating institution approved this retrospective study and waived informed consent. This study was HIPAA compliant. A request for cases through the European Society of Urogenital Radiology network was made to institutions for patients who fit the requirements outlined by the authors, and a prospective follow-up of recipients was performed. Twenty-four tumors were identified that developed in the renal allograft of 20 patients from 11 institutions who were treated with radiofrequency ablation (n = 19) or cryoablation (n = 5) between 2003 and 2010. Maximal diameter of masses was 6-40 mm (median, 19.5 mm). Twenty masses were solid, and four were type 4 cystic masses. Preablation biopsy was performed for solid tumors only. All images and biologic and biopsy reports were retrospectively reviewed. Significant differences were determined by using a paired t test before and after ablation.

RESULTS

Mean follow-up was 27.9 months (range, 7-71 months). Histopathologic examination revealed papillary carcinoma in 17 patients and clear cell carcinoma in three. Tumors were successfully treated with ultrasonographic guidance in six patients, with computed tomographic guidance in 10 patients, and with both in four patients. One case of infection of the tumor site and one case of transitory genitofemoral nerve injury were the only reported complications. No significant change of renal function was noted. Subsequent imaging follow-up did not reveal any case of recurrence in the ablative site.

CONCLUSION

Percutaneous thermal ablation of renal tumors occurring in renal grafts is effective, with low morbidity. .

Renal cell carcinoma in the native and allograft kidneys of renal transplant recipients

PURPOSE

Renal cell carcinoma develops in renal transplant recipients 30 or more times more commonly than in the general population. We assessed the prevalence, histology and outcome of renal cell carcinoma in a large, single center recipient population.

MATERIALS AND METHODS

We examined outcomes in patients who underwent renal transplantation at our center to determine the prevalence, histology and outcome of those in whom renal cell carcinoma developed.

RESULTS

A total of 3,568 patients received a renal allograft at our institution between 1966 and 2009. A total of 45 renal cell carcinomas were diagnosed in the native kidney of 39 patients (1.1%) and in 8 (0.2%) renal cell carcinoma developed in the allograft kidney. Mean age at diagnosis was 51.6 and 48.2 years in patients with native kidney and allograft tumors, respectively. The mean interval between transplantation and the native or allograft renal cell carcinoma diagnosis was 10.6 and 12.1 years, respectively. Clear cell renal cell carcinoma was the most common tumor histology in native kidneys, diagnosed in 21 cases, while papillary renal cell carcinoma was diagnosed in 20. Five allograft tumors were papillary renal cell carcinoma and 3 were clear cell renal cell carcinoma. Native kidney tumors were managed by radical nephrectomy in 44 or by observation after biopsy. Allograft tumors were managed by transplant nephrectomy in 3 cases, radio frequency ablation in 3 and partial nephrectomy in 2. At a mean 6.6-year followup 32 patients with native kidney renal cell carcinoma were alive while 7 with allograft tumors were alive at a mean 3.6-year followup.

CONCLUSIONS

Renal cell carcinoma is more prevalent in patients with renal transplantation than the general population, although the subtype distribution differs. Excellent survival is seen at more than 6 years after treatment.

[Results of nephrectomy for native kidney tumors in renal transplanted patients]

OBJECTIVE

Evaluate epidemiology, diagnosis and outcome of de novo renal cell carcinoma in renal transplanted patients.

PATIENTS AND METHOD

From June 1989 to December 2007, 824 renal transplantations were carried out and followed in annual consultation by an urologist with abdominal echography or tomodensitometry. The suspect renal lesions were treated by a widened nephrectomy. Incidence, diagnosis, treatment, histological type, and outcome of all patients were analysed.

RESULTS

Thirty-three patients had nephrectomy for suspect renal lesions. Twenty-two de novo tumours of native kidneys among 21 patients were diagnosed (15 renal clear cell carcinoma and seven papillary tumours) with mean time after transplantation of 25,6 months (2.3-105.5). All tumours were classified pT1aN0M0. Only one patient died at 8 months of metastatic dissemination of a papillary tumour classified initially pT1aN0M0. All the other patients are alive with mean follow-up of 34.8 months (2.8-113.9). Specific survival to 5 years was 93.3%.

CONCLUSION

The increase risk of tumour at the renal transplanted patient led to propose in the event of suspect lesions of the native kidneys, a widened nephrectomy. In our series, 65% of the operated patients carried a cancer. The good forecast of these localized tumours justifies a regular radiological monitoring and an aggressive therapeutic attitude despite of absence of tumours in 35% of the transplanted patients.

Renal cell carcinoma of native kidney in Chinese renal transplant recipients: a report of 12 cases and a review of the literature

Objectives

To present and discuss the epidemiological and clinical aspects, as well as therapeutic options and outcome of de novo renal cell carcinoma (RCC) of the native kidneys in a series of Chinese renal transplant recipients.

Patients and Methods

A retrospective, cohort study examining all renal transplant recipients with the diagnosis of RCC of native kidney followed up in two major regional hospitals in Hong Kong between January 2000 and December 2009. Clinical data included age, gender, cause of renal failure, symptoms at presentation, duration of transplantation, immunosuppressive therapy, and history of acquired cystic kidney disease (ACKD). Laboratory, radiographic, operative, and pathology reports were used to assess the tumor extent.

Results

Among the 1,003 renal transplant recipients recruited, 12 transplant recipients had a nephrectomy for a total of 13 RCC. The prevalence of de novo RCC was 1.3%. The mean age at diagnosis of RCC was 48.4 years, and the median time from transplantation to diagnosis was 6.1 years. ACKD was found in 6 (50%) of the patients. All patients except one were asymptomatic. pT1 disease was found in ten patients with a mean tumor size of 3.2 cm. All patients were treated successfully with radical nephrectomy. After a median follow-up of 38 months, two patients (16.7%) died. One died of sepsis, and the other died of metastatic carcinoma.

Conclusions

With increasing data showing a better prognosis if RCC is detected early by screening, it is time to consider screening all kidney transplant recipients for ACKD and RCC.

Renal cell carcinoma of native kidney in renal transplant recipients

OBJECTIVE

To evaluate the prevalence, prognosis and possible risk factors of renal cell carcinoma (RCC) of the native kidney in renal transplant recipients.

PATIENTS AND METHODS

We retrospectively re-examined the follow-up data of 373 consecutive renal transplant recipients at our institution between August 1993 and September 2004. We collected the data of all de novo RCC of the native kidney in the current analysis.

RESULTS

Of the 373 patients examined, 12 tumours of the native kidney were diagnosed in 10 individuals. The mean ages at transplantation and diagnosis were 33 and 45.8 years, respectively. Thirteen malignancies were discovered fortuitously. Among the renal ultrasonograms there were two false-negative results. The mean tumour size was 21 mm. Nephrectomy was performed in all cases. Among the 12 kidney malignancies, there were five conventional RCCs and seven papillary RCCs. Half of all tumours were Furhman Grade 3 lesions, and pT1aN0M0 tumours also accounted for all malignancies in the current cohort. One of the 10 patients died, from progression of metastases 6 years after diagnosis. One patient had a local recurrence 2 years after diagnosis. The other eight patients were alive with no evidence of disease at the time of the current report. No significant relationship was detected between RCC occurrence and clinical patient characteristics.

CONCLUSIONS

There appears to be a greater risk of RCC of the native kidney in patients with end-stage renal disease. The present results suggest that an annual examination of the native kidney before and after renal transplantation is essential.

Epstein-Barr Virus-Negative Posttransplant Lymphoproliferative Disorder With Coexisting Native Renal Cell Carcinoma: PET/CT Demonstration

Compared with the general population, solid organ transplant recipients, including renal transplant patients, who are under long-term immunosuppression, present with up to a 120-fold increased risk of developing skin cancer and non-Hodgkin lymphoma. For the renal transplant population with prior long-term dialysis, there is also an enhanced potentiality of native kidney malignancy. The authors present a case with a posttransplant lymphoproliferative disorder of the duodenum and concomitant left native papillary renal cell carcinoma. The uncommon coexistence of these 2 malignant processes is demonstrated by PET/CT imaging.

De novo renal cell carcinoma of native kidney in renal transplant recipients

BACKGROUND

The 10-year risk of developing a solid malignancy is 20% for kidney transplant recipients. The goal of the current study was to investigate the epidemiology and the diagnostic and prognostic parameters associated with de novo malignancies of the native kidney among transplant recipients at the authors' institution (Department of Urology and Renal Transplantation, Hôpital Salvator, Marseille, France).

METHODS

The authors reexamined the follow-up of 933 consecutive transplant recipients at their institution between 1987 and 2003. Immunossupressive therapy was not modified in the event of malignant disease, nor was systematic radiologic monitoring of native kidneys performed. All de novo malignancies of the native kidney were included in the current analysis.

RESULTS

Among the 933 patients examined, a combined total of 12 malignancies of the native kidney were diagnosed in 11 individuals. For these 11 individuals, the average ages at transplantation and diagnosis were 42.5 and 49.1 years, respectively. Ten malignancies were discovered fortuitously, whereas two were symptomatic. Among the 10 renal echographies performed, there was 1 false-negative result. Tomodensitometry was performed in 11 cases and yielded no false-negative results. The average tumor size was 37 mm. Nephrectomy was performed in 10 cases, and biopsy was performed in 1. Among the 12 kidney malignancies encountered in the current study, there were 7 conventional cell carcinomas, 3 basophilic papillary carcinomas, and 2 chromophobic renal cell carcinomas. Half of all tumors were Furhman Grade 3 lesions, and pT1aN0M0 tumors (2003 TNM staging system) also accounted for half of all malignancies in the current cohort. Two affected transplant recipients died (one due to disease), and the remaining nine are alive without recurrence and with normal renal functioning (median follow-up, 39 months).

CONCLUSIONS

There appears to be an increased risk of malignancy of the native kidney in renal transplant recipients, with high-grade and papillary tumors being particularly common. Consequently, systematic radiologic follow-up of native kidneys must be performed for individuals who undergo kidney transplantation.

Racial and ethnic variations in incidence and pattern of malignancies after kidney transplantation

Malignancies are a well-recognized complication of renal transplantation. Although the problem is well studied in developed countries, less is known about it in developing countries. Although geographic and ethnic variations have been alluded to in several reports, to our knowledge the subject has not been investigated formally. From April 1976 through March 1999, 41 (7.6%) patients were diagnosed with cancer among a heterogeneous population of renal allograft recipients treated at our institution in Cape Town, South Africa. The incidence of malignancies was comparable in white and nonwhite patients. However, squamous cell cancer and basal cell cancer of the skin (in that order) were the most common cancers in white patients, in whom they occurred exclusively. On the other hand, Kaposi sarcoma was the most common cancer in nonwhite renal allograft recipients, in whom it accounted for almost 80% of all cancers. Review of the world literature suggests that posttransplant cancers are less common in developing countries; Kaposi sarcoma is the most common lesion, with few exceptions. Malignant lymphomas are also more common in developing countries. The impact of different immunosuppressive regimens is controversial. In general, cyclosporine is not associated with a significant increase in the incidence of cancer after renal transplantation, although the time to the first cancer may be reduced. In our experience, the pattern of posttransplant cancers in white and nonwhite patients living in the same geographic region epitomizes the world experience of the disease and suggests that genetic factors, rather than geography, are the more important determinants of cancer development after renal transplantation.

Persistent dipstick haematuria following renal transplantation

Despite widespread testing for dipstick haematuria following renal transplantation, there are no published series describing the prevalence and possible causes of this complication in an adult population. A cross-sectional study of 640 renal transplant recipients under review at our follow-up clinic was performed. Persistent haematuria was defined as a minimum of 1+ of blood on urinalysis stick testing detected at not fewer than 75% of clinic visits since its onset, or since the start of routine testing, present over a period of at least 4 weeks. The prevalence of persistent dipstick haematuria was 13.3%. Median serum creatinine was higher in patients with persistent haematuria but age, gender and length of time since transplantation were not significantly different. Potential explanations for persistent haematuria in 21 of 85 affected patients were chronic infection, ureteric stent without chronic infection, regular or intermittent self-catheterization, persistent menstrual bleeding, anticoagulant therapy, graft calculus, and allograft renal cell carcinoma. Recurrent or de novo glomerular disease was confirmed by graft biopsy in 10 of 85 patients. Among the 41 recipients whose original cause of renal failure was IgA nephropathy (IgAN), the prevalence of persistent haematuria was 31.7% compared with 12% in the remaining patients (relative risk 2.6, 95% CI: 1.6-4.3). Persistent haematuria in IgAN patients was not associated with gender, age or time since transplantation. After 29 months of follow-up, 20% of patients with haematuria had progressed to graft failure or death compared with 11.6% of the unaffected group (p = 0.029). However, despite the association with earlier graft failure, haematuria did not predict this endpoint independently of renal function.