Primary Renal Cell Carcinoma in a Transplanted Kidney: Genetic Evidence of Recipient Origin

Management of renal cell carcinoma in transplant kidney: a systematic review and meta-analysis

INTRODUCTION

After transplantation, approximately 10% of renal cell carcinomas are detected in graft kidneys. These tumors (gRCC) present surgeons with the difficulty of finding a treatment that guarantees both oncological clearance and maintenance of function. We conducted a systematic review and an individual patient data meta-analysis on the oncology, safety and functional outcomes of the available treatments for gRCC.

EVIDENCE ACQUISITION

A systematic search was performed across MEDLINE, EMBASE, and Web of Science including any study reporting perioperative, functional and survival outcomes for patients undergoing graft nephrectomy (GN), partial nephrectomy (PN) or thermal ablation (TA) for gRCC. Quade's ANCOVA, Spearman Rho and Pearson χ², Kaplan-Meier, Log-rank and Standard Cox regression and other tests were used to compare treatments. Studies' quality was evaluated using a modified version of Newcastle Ottawa Scale.

EVIDENCE SYNTHESIS

A number of 29 studies (357 patients) were included. No differences between TA and PN were found in terms of safety, functional and oncological outcomes for T1a gRCCs. When applied to pT1b gRCC, PN showed no difference in complications, progression or cancer-specific deaths compared to smaller lesions; PN validity for pT2 gRCCs should be considered unverified due to lack of sufficient evidence. The efficacy and safety of PN or TA for multiple gRCC remain controversial. In case of non-functioning, large (T≥2), complicated or metastatic gRCCs, GN appears to be the most reasonable choice. Quality of evidence ranged from very low to moderate. Studies with large cohorts and longer follow-up are still needed to clarify oncological and functional differences.

CONCLUSIONS

PN and TA might be offered as a nephron-sparing treatment in patients with T1a gRCC. There is no significant difference between these options and GN in terms of oncological outcomes and complications. PN and TA offer similar functional outcomes and graft preservation. PN for T1b gRCC seems feasible and safe, but its validity should be considered unverified.

Tumors after kidney transplantation: a population study

One of the main causes of post-transplant-associated morbidity and mortality is cancer. The aims of the project were to study the neoplastic risk within the kidney transplant population and identify the determinants of this risk. A cohort of 462 renal transplant patients from 2010 to 2020 was considered. The expected incidence rates of post-transplant cancer development in the referenced population, the standardized incidence ratios (SIR) taking the Italian population as a comparison, and the absolute risk and the attributable fraction were extrapolated from these cohorts of patients. Kidney transplant recipients had an overall cancer risk of approximately three times that of the local population (SIR 2.8). A significantly increased number of cases were observed for Kaposi's sarcoma (KS) (SIR 195) and hematological cancers (SIR 6.8). In the first 3 years post-transplant, the risk to develop either KS or hematological cancers was four times higher than in the following years; in all cases of KS, the diagnosis was within 2 years from the transplant. Post-transplant immunosuppression represents the cause of 99% of cases of KS and 85% of cases of lymphomas, while only 39% is represented by solid tumors. Data related to the incidence, the percentages attributable to post-transplant immunosuppression, and the time of onset of neoplasms, particularly for KS and hematological tumors could help improve the management for the follow-up in these patients.

Donor-derived urologic cancers after renal transplantation: A retrospective non-randomized scientific analysis

Background

Malignancies in the urinary tract and the kidney graft are quite common after kidney transplantation. In some selected cases tumours develop from donor-derived tissue.

Objectives

We hypothesised that there is a clinical value to investigate donor/recipient origin in urologic malignancies in renal transplant recipients.

Methods

In this retrospective study, including patients transplanted between the years 1969 and 2014 at Uppsala University Hospital, Sweden, 11 patients with malignancies in urinary tract and 4 patients with malignancies in kidney transplants were investigated. Donor/recipient origin of tumour tissue was analysed by polymerase chain reaction (PCR) of human leucocyte antigen (HLA) genotypes or by fluorescence in situ hybridization (FISH analysis) of sex chromosomes. HLA genotype and sex chromosomes of the tumour were compared to the known HLA genotype and sex chromosomes of recipient and donor.

Results

Three of ten cancers in the urinary tract and three of four cancers in the kidney transplants were donor-derived.

Conclusions

We suggest that urologic malignancies in renal transplant recipients can be investigated for transplant origin. In addition to conventional therapy the allograft immune response against these tumours can be valuable to treat donor-derived cancers.

Malignancy Diseases in Kidney Transplantation, Clinical Outcomes, Patient, and Allograft Survival: A Case-Control Study

BACKGROUND

Malignancy is a well-known complication in patients after kidney transplantation (KT), but its effect on posttransplant outcomes, allograft, and patient survival remains unexplored. The aim of this study is to report the impact of the comorbidity on clinical outcome, function, and failure of an allograft kidney.

METHODS

This case-control study included 101 KT patients. Twenty-six patients who developed cancer (CA) were assigned to the case group and 75 to the control group. Statistical analysis was performed using logistic regression models, and graft survival was analyzed using the Kaplan-Meier curve.

RESULTS

Non-melanoma skin CA was the most common malignancy, accounting for almost 60% of cases, followed by stomach CA, prostate CA, and lymphoproliferative diseases (7.70% each). Difference in graft and patient survival was not significant between the two groups (P > .05). A tumor in nonfunctioning in the first nonfunctioning KT was identified in 1 KT patient with a second allograft and by anatomopathological was detect Fuhrman grade II renal cell carcinoma. This KT patient was in good clinical condition with serum creatinine level of 1.5 mg/dL.

CONCLUSIONS

No association was observed between CA development and risk factors, including family history and smoking habit, and no differences in allograft and patient survival were found. Nevertheless, in our data, CA in KT patients occurred early after transplantation. Renal cell carcinoma in allograft failure was identified in a patient; that suggested that nephrectomy of kidney failure must be performed to avoid patient allosensitization and neoplasia. Thus, we suggest continuous screening of malignancy diseases for KT patients.

Incidence, management and treatment outcomes of renal malignancy in a post-transplant recipient at a tertiary care centre: A 16-year experience

Introduction and Objective:

Although the incidence of malignancy in renal transplant recipients is on the rise owing to boom in the post-transplant immunosuppressive therapy, there is paucity of literature regarding their reporting and management. In this study, we report the incidence of de novo renal malignancies, post-renal transplantation at our centre over a 16-year period and discuss their management.

Methods:

All patients who underwent renal transplantation at our department between March 2004 and February 2020 were included and retrospectively reviewed. We analysed the incidence of renal malignancy both in the native kidney and the graft, histological subtype, time to and type of treatment.

Results:

A total of 376 patients underwent renal transplantation. Mean age of recipients was 48.2 and 52.15 years among those who developed cancer. 13 (2.93%) of 376 recipients developed urogenital malignancy, of whom 8 had renal cell carcinoma (RCC) in their native kidneys and 1 in the allograft. Transitional cell carcinoma (TCC) of renal pelvis was noted in three patients with one concomitant TCC of bladder. No treatment-related graft losses occurred in the native kidney malignancy. Patients with RCC underwent nephrectomy while TCC of renal pelvis underwent nephroureterectomy with bladder cuff excision. Transurethral resection was done for bladder tumour. All patients were followed up as per standard protocol.

Conclusion:

A rise in urological post-transplant malignancies mandates regular surveillance after renal transplantation to ensure early detection of de novo malignancies and early initiation of treatment. Goal should be to minimise adverse graft outcomes with no compromise on oncological outcomes.

Level of evidence:

Not applicable

[Renal cell carcinoma of the kidney transplant: The French guidelines from CTAFU]

OBJECTIVE

To propose recommendations for the management of renal cell carcinomas (RCC) of the renal transplant.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU to evaluate prevalence, diagnosis and management of RCC arousing in the renal transplant. References were assessed according to a predefined process to propose recommendations with levels of evidence.

RESULTS

Renal cell carcinomas of the renal transplant affect approximately 0.2% of recipients. Mostly asymptomatic, these tumors are mainly diagnosed on a routine imaging of the renal transplant. Predominant pathology is clear cell carcinomas but papillary carcinomas are more frequent than in general population (up to 40-50%). RCC of the renal transplant is often localized, of low stage and low grade. According to tumor characteristics and renal function, preferred treatment is radical (transplantectomy) or nephron sparing through partial nephrectomy (open or minimally invasive approach) or thermoablation after percutaneous biopsy. Although no robust data support a switch of immunosuppressive regimen, some authors suggest to favor the use of mTOR inhibitors. CTAFU does not recommend a mandatory waiting time after transplantectomy for RCC in candidates for a subsequent renal tranplantation when tumor stage<T3 and low ISUP grade.

CONCLUSION

These French recommendations should contribute to improving the oncological and functional prognosis of renal transplant recipients by improving the management of RCC of the renal transplant.

Treatment options for localised renal cell carcinoma of the transplanted kidney

Currently, there is no consensus among the transplant community about the treatment of renal cell carcinoma (RCC) of the transplanted kidney. Until recently, graftectomy was universally considered the golden standard, regardless of the characteristics of the neoplasm. Due to the encouraging results observed in native kidneys, conservative options such as nephron-sparing surgery (NSS) (enucleation and partial nephrectomy) and ablative therapy (radiofrequency ablation, cryoablation, microwave ablation, high-intensity focused ultrasound, and irreversible electroporation) have been progressively used in carefully selected recipients with early-stage allograft RCC. Available reports show excellent patient survival, optimal oncological outcome, and preserved renal function with acceptable complication rates. Nevertheless, the rarity and the heterogeneity of the disease, the number of options available, and the lack of long-term follow-up data do not allow to adequately define treatment-specific advantages and limitations. The role of active surveillance and immunosuppression management remain also debated. In order to offer a better insight into this difficult topic and to help clinicians choose the best therapy for their patients, we performed and extensive review of the literature. We focused on epidemiology, clinical presentation, diagnostic work up, staging strategies, tumour characteristics, treatment modalities, and follow-up protocols. Our research confirms that both NSS and focal ablation represent a valuable alternative to graftectomy for kidney transplant recipients with American Joint Committee on Cancer stage T1aN0M0 RCC. Data on T1bN0M0 lesions are scarce but suggest extra caution. Properly designed multi-centre prospective clinical trials are warranted.

Systematic review of ablative therapy for the treatment of renal allograft neoplasms

BACKGROUND

To date, there are no guidelines on the treatment of solid neoplasms in the transplanted kidney. Historically, allograft nephrectomy has been considered the only reasonable option. More recently, nephron-sparing surgery (NSS) and ablative therapy (AT) have been proposed as alternative procedures in selected cases.

AIM

To review outcomes of AT for the treatment of renal allograft tumours.

METHODS

We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2009 Checklist. PubMed was searched in March 2019 without time restrictions for all papers reporting on radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE) of solid tumours of the kidney allograft. Only original manuscripts describing actual cases and edited in English were considered. All relevant articles were accessed in full text. Additional searches included all pertinent references. Selected studies were also assessed for methodological quality using a tool based on a modification of the Newcastle Ottawa scale. Data on recipient characteristics, transplant characteristics, disease characteristics, treatment protocols, and treatment outcomes were extracted and analysed. Given the nature and the quality of the studies available (mostly retrospective case reports and small retrospective uncontrolled case series), a descriptive summary was provided.

RESULTS

Twenty-eight relevant studies were selected describing a total of 100 AT procedures in 92 patients. Recipient age at diagnosis ranged from 21 to 71 years whereas time from transplant to diagnosis ranged from 0.1 to 312 mo. Most of the neoplasms were asymptomatic and diagnosed incidentally during imaging carried out for screening purposes or for other clinical reasons. Preferred diagnostic modality was Doppler-ultrasound scan followed by computed tomography scan, and magnetic resonance imaging. Main tumour types were: papillary renal cell carcinoma (RCC) and clear cell RCC. Maximal tumour diameter ranged from 5 to 55 mm. The vast majority of neoplasms were T1a N0 M0 with only 2 lesions staged T1b N0 M0. Neoplasms were managed by RFA (n = 78), CA (n = 15), MWA (n = 3), HIFU (n = 3), and IRE (n = 1). Overall, 3 episodes of primary treatment failure were reported. A single case of recurrence was identified. Follow-up ranged from 1 to 81 mo. No cancer-related deaths were observed. Complication rate was extremely low (mostly < 10%). Graft function remained stable in the majority of recipients. Due to the limited sample size, no clear benefit of a single procedure over the other ones could be demonstrated.

CONCLUSION

AT for renal allograft neoplasms represents a promising alternative to radical nephrectomy and NSS in carefully selected patients. Properly designed clinical trials are needed to validate this therapeutic approach.

Renal cell carcinoma in renal allograft: Case series and review of literature

Renal cell carcinoma (RCC) in transplanted kidneys has been reported sporadically with incidence of about 0.5%. There are currently no standard guidelines on the management of allograft RCC in renal transplant recipients. Our objective was to study effectiveness of nephron-sparing surgery (NSS) for allograft RCC. We performed a retrospective analysis of patients with RCC in renal allografts managed with NSS in our institution from January 2000 to December 2015. Patient demographics, interval between transplant and RCC diagnosis, operative parameters, perioperative complications, final pathology, and renal function were evaluated. Three females underwent successful NSS for allograft RCC. Cause of end-stage renal disease was IgA nephropathy in all; mean time between renal transplant and diagnosis of RCC was 23 years. We were able to stay extraperitoneal in all the cases. In the final pathology, two had papillary and one had clear cell RCC. One patient developed pyelocutaneous fistula which was managed by stenting. Long-term functional outcomes of NSS are excellent; none of our patients is dialysis dependent.

The Role of Hypoxia and Cancer Stem Cells in Renal Cell Carcinoma Pathogenesis

The cancer stem cell (CSC) model has recently been approached also in renal cell carcinoma (RCC). A few populations of putative renal tumor-initiating cells (TICs) were identified, but they are indifferently understood; however, the first and most thoroughly investigated are CD105-positive CSCs. The article presents a detailed comparison of all renal CSC-like populations identified by now as well as their presumable origin. Hypoxic activation of hypoxia-inducible factors (HIFs) contributes to tumor aggressiveness by multiple molecular pathways, including the governance of immature stem cell-like phenotype and related epithelial-to-mesenchymal transition (EMT)/de-differentiation, and, as a result, poor prognosis. Due to intrinsic von Hippel-Lindau protein (pVHL) loss of function, clear-cell RCC (ccRCC) develops unique pathological intra-cellular pseudo-hypoxic phenotype with a constant HIF activation, regardless of oxygen level. Despite satisfactory evidence concerning pseudo-hypoxia importance in RCC biology, its influence on putative renal CSC-like largely remains unknown. Thus, the article discusses a current knowledge of HIF-1α/2α signaling pathways in the promotion of undifferentiated tumor phenotype in general, including some experimental findings specific for pseudo-hypoxic ccRCC, mostly dependent from HIF-2α oncogenic functions. Existing gaps in understanding both putative renal CSCs and their potential connection with hypoxia need to be filled in order to propose breakthrough strategies for RCC treatment.

Downregulation of the Deiminase PADI2 Is an Early Event in Colorectal Carcinogenesis and Indicates Poor Prognosis

Peptidyl arginine deiminases (PADI) are a family of enzymes that catalyze the poorly understood posttranslational modification converting arginine residues into citrullines. In this study, the role of PADIs in the pathogenesis of colorectal cancer was investigated. Specifically, RNA expression was analyzed and its association with survival in a cohort of 98 colorectal cancer patient specimens with matched adjacent mucosa and 50 controls from donors without cancer. Key results were validated in an independent collection of tumors with matched adjacent mucosa and by mining of a publicly available expression data set. Protein expression was analyzed by immunoblotting for cell lines or IHC for patient specimens that further included 24 cases of adenocarcinoma with adjacent dysplasia and 11 cases of active ulcerative colitis. The data indicate that PADI2 is the dominantly expressed PADI enzyme in colon mucosa and is upregulated during differentiation. PADI2 expression is low or absent in colorectal cancer. Frequently, this occurs already at the stage of low-grade dysplasia. Mucosal PADI2 expression is also low in ulcerative colitis. The expression level of PADI2 in tumor and adjacent mucosa correlates with differential survival: low levels associate with poor prognosis.

IMPLICATIONS

Downregulation of PADI2 is an early event in the pathogenesis of colorectal cancer associated with poor prognosis and points toward a possible role of citrullination in modulating tumor cells and their microenvironment. Mol Cancer Res; 14(9); 841-8. ©2016 AACR.

A cellular model reflecting the phenotypic heterogeneity of mutant HRAS driven squamous cell carcinoma

Squamous cell carcinomas have a range of histopathological manifestations. The parameters that determine this clinically observed heterogeneity are not fully understood. Here, we report the generation of a cell culture model that reflects part of this heterogeneity. We have used the catalytic subunit of human telomerase hTERT and large T to immortalize primary UV-unexposed keratinocytes. Then, mutant HRAS G12V has been introduced to transform these immortal keratinocytes. When injected into immunosuppressed mice, transformed cells grew as xenografts with distinct histopathological characteristics. We observed three major tissue architectures: solid, sarcomatoid and cystic growth types, which were primarily composed of pleomorphic and basaloid cells but in some cases displayed focal apocrine differentiation. We demonstrate that the cells generated represent different stages of skin cancerogenesis and as such can be used to identify novel tumor-promoting alterations such as the overexpression of the PADI2 oncogene in solid-type SCC. Importantly, the cultured cells maintain the characteristics from the xenograft they were derived from while being amenable to manipulation and analysis. The availability of cell lines representing different clinical manifestations opens a new tool to study the stochastic and deterministic factors that cause case-to-case heterogeneity despite departing from the same set of oncogenes and the same genetic background.

Renal cell carcinoma in functional renal graft: Toward ablative treatments

The occurrence of a kidney transplant tumor is a rare but serious issue with a double risk: the return to dialysis and the development of metastatic cancer. Publications on this topic are mainly case reports. The purpose of this review was to report an exhaustive literature review of functional graft renal cell carcinomas to highlight the impact of tumors on the renal graft outcomes. 201 de novo renal carcinomas in functional renal grafts from 69 publications were included. Incidence was estimated at 0.18%. Graft tumors were mostly asymptomatic (85.9%). Whatever the discovery circumstances of graft tumors, they were mostly documented by graft ultrasounds supplemented by CT-scanning or MR imaging. Nephron sparing surgery (95 patients) was the first treatment performed followed by radiofrequency ablation (38 patients) and cryotherapy (10 patients). The most common tumor graft histology was clear cell carcinoma (46.4%), followed by papillary carcinoma (43.7%). Specific mortality was 2.9% with 6 deaths. Renal graft cell carcinoma is a rare pathology with a low specific death. When possible, conservative treatment should be the first choice.

Malignancies arising in allograft kidneys, with a first reported translocation RCC post-transplantation: A case series

BACKGROUND

The increased risk of malignancy in the post-renal transplant population has been well documented. Renal carcinoma is more common in this population, usually arising in native kidneys. Rarely, tumors arise in the transplanted kidney. Our case series reports four cases of malignancy in allograft kidneys, one of which is a first reported case of translocation RCC in a transplanted kidney.

METHODS

The renal transplantation database (1584 patients) at St. Michael's Hospital was reviewed for malignancies arising in allograft kidneys: reports and pathology slides were reviewed.

RESULTS

Four cases of malignancies arising in the allograft kidney were identified among our kidney transplant population. One patient developed a high grade urothelial carcinoma in the donor kidney post BK virus infection. The other 3 cases were renal cell carcinomas: one clear cell renal cell carcinoma, one translocation renal cell carcinoma, and one papillary renal cell carcinoma. The translocation renal cell cancer had confirmed TFE3 protein over-expression by immunohistochemistry. Molecular testing of the tumors in all 4 cases identified two separate genetic profiles, favored to represent tumors arising from donor tissues along with infiltrating recipient lymphocytes.

DISCUSSION

Previous reports suggested that epithelial malignancies in allograft kidneys are rare. We identified 4 such tumors in 1584 transplant patients. Further, we identified the first reported case of translocation RCC in an allograft kidney. While the rate of malignancy in allograft kidneys is low, screening of the donor kidneys by ultrasound and/or urine cytology may be of use in detecting these lesions.

Assessment of chimerism in epithelial cancers in transplanted patients

Cancer is now the most severe complication in the long term in transplant recipients. As most solid-organ or hematopoietic stem-cell transplantations are allogeneic, chimerism studies can be performed on cancers occurring in recipients. We summarize here the different methods used to study chimerism in cancers developing in allogeneic-transplant recipients, analyze their respective advantages and report the main results obtained from these studies. Chimerism analyses of cancers in transplant recipients require methods suited to tissue samples. In the case of gender-mismatched transplantation, the XY chromosomes can be explored using fluorescent in situ hybridization on whole-tissue sections or Y-sequence-specific PCR after the laser microdissection of tumor cells. For cancers occurring after gender-matched transplantation, laser microdissection of tumor cells enables studies of microsatellite markers and high-resolution melting analysis of mitochondrial DNA on genes with marked polymorphism, provided these are different in the donor and the recipient. The results of different studies address the cancers that develop in both recipients and in transplants. The presence of chimeric cells in these two types of cancer implies an exchange of progenitor/stem-cells between transplant and recipient, and the plasticity of these progenitor/stem-cells contributes to epithelial cancers. The presence of chimeric cells in concomitant cancers and preneoplastic lesions implies that the oncogenesis of these cancers progresses through a multistep process.

Giant cavernous hemangioma in renal graft: a case report

BACKGROUND

We present a case of giant cavernous hemangioma in renal graft tumor; we have not found any cases described in literature.

CLINICAL CASE

Patient transplanted from a deceased donor, 8 years previous to her admission due to deterioration in renal function, observing a 12-cm renal mass in the front face of the renal graft, which displaces it, provoking obstructive uropathy. On ultrasonography and computed tomography, it is seen as a complicated, cystic lesion. Tumorectomy with a good functional recovery of the graft was carried out. A histopathologic study showed a mass with extensive adherences to the perirenal adipose tissue and a cross section showed a spongy appearance with blood clots in the centre, microscopically formed by vascular channels, lined by a layer of endothelial cells, and filled with blood.

CONCLUSIONS

Giant cavernous hemangioma in renal graft tumor has not been previously described. Given its benign condition, nephron-sparing surgery should be carried out if possible.

MacroH2A1 regulates the balance between self-renewal and differentiation commitment in embryonic and adult stem cells

One of the most striking epigenetic alterations that occurs at the level of the nucleosome is the complete exchange of the canonical H2A histones for the macroH2A variant. Here, we provide insight into the poorly recognized function of macroH2A in transcriptional activation and demonstrate its relevance in embryonic and adult stem cells. Knockdown of macroH2A1 in mouse embryonic stem (mES) cells limited their capacity to differentiate but not their self-renewal. The loss of macroH2A1 interfered with the proper activation of differentiation genes, most of which are direct target genes of macroH2A. Additionally, macroH2A1-deficient mES cells displayed incomplete inactivation of pluripotency genes and formed defective embryoid bodies. In vivo, macroH2A1-deficient teratomas contained a massive expansion of malignant, undifferentiated carcinoma tissue. In the heterogeneous culture of primary human keratinocytes, macroH2A1 levels negatively correlated with the self-renewal capacity of the pluripotent compartment. Together these results establish macroH2A1 as a critical chromatin component that regulates the delicate balance between self-renewal and differentiation of embryonic and adult stem cells.

Biopsy-confirmed de novo renal cell carcinoma (RCC) in renal grafts: a single-centre management experience in a 2396 recipient cohort

OBJECTIVE

To study the natural history of renal cell carcinoma (RCC) development in renal grafts and their management.

PATIENTS AND METHODS

We report a single-centre series of de novo RCC in allografts from a cohort of 2396 consecutive renal transplant recipients.

RESULTS

In all, 17 RCCs were detected in 12 patients, representing 0.5% of kidney recipients. The mean patient age was 55 years and the time to RCC diagnosis since transplantation was 13 years. The mean diameter of the RCC was 23 mm. Biopsies were taken in all cases. Concordance between biopsy and surgical specimens was 100% for nuclear grade and pathological type. Four graft removals were performed and six patients underwent nephron-sparing surgery (NSS). Two cryoablations were performed. Overall, nine papillary RCC, five clear cell carcinomas, and one chromophobe cell carcinoma were removed surgically. The mean follow-up was 43 months. One local recurrence was reported in a patient treated by NSS.

CONCLUSIONS

Our findings support evidence that radiological screening of kidney recipients allows the detection of small tumours for which a conservative management by NSS or non-surgically destructive techniques can be proposed with mid-term oncological safety. Systematic tumour biopsy may help in the management and treatment decision. Several questions remain unanswered such as the importance of mammalian target of rapamycin inhibitors in the chemoprevention of the recurrence and the genetic cell origin of RCC in renal grafts.

A lucky fall? Case report

Renal cell carcinomas (RCCs) account for 3% of all solid neoplasms, with an increased incidence after renal transplantation. In transplant recipients, RCCs predominantly occur in the patient's native kidneys. Herein is reported a case of a localized RCC of recipient origin that developed in the donor allograft and was detected 8 years after renal transplantation. Treatment with high-intensity focussed ultrasound followed by partial nephrectomy was successful, averting the need for dialysis therapy.

Human Barrett's adenocarcinoma of the esophagus, associated myofibroblasts, and endothelium can arise from bone marrow-derived cells after allogeneic stem cell transplant

This study characterizes the contribution of bone marrow-derived cells (BMDCs) to Barrett's adenocarcinoma of the esophagus using a mouse surgical model of disease and human specimens. Transplantation of bone marrow expressing beta galactosidase into a wild-type mouse, followed by surgical esophagojejunostomy, allowed tracking of BMDCs into the surgical anastomosis and resulting Barrett's metaplasia. Human tissue from a male patient who had been transplanted with female bone marrow and later developed esophageal adenocarcinoma allowed us to tract donor-derived cells into the tumor. Using a combination of antibodies directed against beta-galactosidase (animal studies) and X/Y fluorescent in situ hybridization (FISH) (human studies), combined with specific lineage staining directed against epithelial, fibroblast, endothelial, and leukocyte markers, we show that bone marrow cells contribute to both the epithelial and stromal component of esophageal adenocarcinoma. These findings demonstrate that BMDCs can generate cancer-associated fibroblasts as well as contribute directly to epithelial cells in cancer of the esophagus.