Renal papillary adenoma—a putative precursor of papillary renal cell carcinoma

"Papillary Adenoma-like" Renal Tumor with TFE3 Gene Rearrangement, A Potential Precursor to or Early Event in the Development of TFE3 Translocation Renal Cell Carcinoma

MiT family translocation renal cell carcinomas harbor gene fusion involving members of MiT family of transcription factors. Their precursor lesions have not been identified. Herein, we report the first case of small papillary tumors morphologically resembling papillary adenomas but harboring TFE3 gene alteration. The patient was a 23-year old man with multiple small papillary tumors in the right kidney discovered following a gunshot wound injury. These lesions were < 5 mm, well-circumscribed but not encapsulated tubulopapillary proliferation lined with a single layer of cuboidal cells with WHO/ISUP grade 1 or 2 nuclei. The tumor cells were immunoreactive to PAX8, AMACR, high molecular weight cytokeratin, and keratin 7 and negative for CD10, CA9, TTF1, and cathepsin K. Morphologically and immunohistochemically, these lesions were diagnosed as papillary adenomas. TFE3 gene rearrangement was confirmed by fluorescence in-situ hybridization (FISH) using a TFE3 break-apart probe. We term these tumors "papillary adenoma-like" renal tumor with TFE3 gene rearrangement. These tumors are likely a precursor to or represent an early event in the development of TFE3 translocation renal cell carcinomas. An understanding of such tumors to translocation renal cell carcinoma progression can provide insight into the pathogenic mechanism, and ultimately aid the diagnosis and management of translocation renal cell carcinoma.

Updates in Grading of Renal Cell Carcinomas Beyond Clear Cell Renal Cell Carcinoma and Papillary Renal Cell Carcinoma

The World Health Organization (WHO) recommends grading of clear cell renal cell carcinoma (RCC) and papillary RCC using the WHO/International Society of Urological Pathology (ISUP) grade, which is primarily based on nuclear features. As the spectrum of RCC continues to evolve, with more recently described subtypes in the past decade, literature evidence on grading these subtypes is limited or not available for some tumor types. Herein, we outline a pragmatic approach to the topic of grading RCC, dividing the contemporarily described RCC subtypes into 7 categories based on the potential clinical applicability of grading as a useful prognostic parameter: (1) RCC subtypes that are reasonably validated and recommended for WHO/ISUP grading; (2) RCC subtypes where WHO/ISUP is not applicable; (3) RCC subtypes where WHO/ISUP grading is potentially clinically useful; (4) inherently aggressive RCC subtypes where histologic classification itself confers an aggressive biologic potential; (5) renal epithelial tumors where WHO/ISUP grading provides potentially misleading prognostic implication; (6) renal epithelial neoplasms where low WHO/ISUP grade features are a prerequisite for accurate histologic classification; and (7) renal epithelial neoplasms with no or limited data on grading or incomplete understanding of the biologic potential. Our aim in outlining this approach is 2-fold: (a) identify the gaps in understanding and application of grading in RCC subtypes so that researchers in the field may perform additional studies on the basis of which the important pathologic function of assignment of grade may be recommended to be performed as a meaningful exercise across a wider spectrum of RCC; and (b) to provide guidance in the interim to surgical pathologists in terms of providing clinically useful grading information in RCC based on currently available clinicopathologic information.

Ten-year follow-up of renal adenomatosis with magnetic resonance imaging: a case report

Background

Renal adenomatosis is a rare disease that presents as multiple papillary adenomas in the bilateral kidneys. Moreover, papillary adenoma is considered a precursor to papillary renal cell carcinoma. Therefore, patients with renal adenomatosis may have higher risk of developing malignancy than patients without this benign condition.

Case presentation

We present the case of a 62-year-old Asian woman with past history of papillary thyroid cancer. She underwent contrast-enhanced magnetic resonance imaging of the abdomen to screen for metastasis in 2010 and was followed up with computed tomography or magnetic resonance imaging annually. She was found to have a right renal tumor on computed tomography and underwent partial nephrectomy. The pathological diagnosis of the right renal tumor was angiomyolipoma. Renal adenomatosis was also histologically confirmed in the renal parenchyma adjacent to the angiomyolipoma. In this case report, we demonstrate the natural course of renal adenomatosis over 10 years using imaging studies. The benign tumors gradually progressed during the follow-up period. Larger tumor sizes and more hypoenhanced nodules in the bilateral kidneys were observed on follow-up computed tomography and magnetic resonance imaging.

Conclusions

Due to its malignant potential, the clinical course of renal adenomatosis must be monitored. We present the natural course of renal adenomatosis with magnetic resonance imaging during a 10-year follow-up period.

The evolution and ecology of benign tumors

Tumors are usually classified into two main categories - benign or malignant, with much more attention being devoted to the second category given that they are usually associated with more severe health issues (i.e., metastatic cancers). Here, we argue that the mechanistic distinction between benign and malignant tumors has narrowed our understanding of neoplastic processes. This review provides the first comprehensive discussion of benign tumors in the context of their evolution and ecology as well as interactions with their hosts. We compare the genetic and epigenetic profiles, cellular activities, and the involvement of viruses in benign and malignant tumors. We also address the impact of intra-tumoral cell composition and its relationship with the tumoral microenvironment. Lastly, we explore the differences in the distribution of benign and malignant neoplasia across the tree of life and provide examples on how benign tumors can also affect individual fitness and consequently the evolutionary trajectories of populations and species. Overall, our goal is to bring attention to the non-cancerous manifestations of tumors, at different scales, and to stimulate research on the evolutionary ecology of host-tumor interactions on a broader scale. Ultimately, we suggest that a better appreciation of the differences and similarities between benign and malignant tumors is fundamental to our understanding of malignancy both at mechanistic and evolutionary levels.

Symptomatic giant renal oncocytoma with an incidental papillary adenoma

Renal oncocytomas are benign, slow-growing tumours accounting for 3-7% of all solid renal neoplasms. These tumours tend to be small, unilateral and asymptomatic and are often discovered incidentally on imaging. Large oncocytomas are rare and can be difficult to distinguish from renal cell carcinoma based off clinical findings or imaging characteristics alone. Papillary adenomas are also benign renal neoplasms but arising from the renal tubular epithelium and almost always located within the cortex. We present a case of a 63-year-old Caucasian male with a large symptomatic renal oncocytoma with an incidental concurrent papillary adenoma.

Clinicopathological and molecular characterisation of papillary renal neoplasm with reverse polarity and its renal papillary adenoma analogue

AIMS

Papillary renal neoplasm with reverse polarity (PRNRP) is a newly defined entity with distinct histomorphology and recurrent KRAS mutation. It has been estimated to constitute 4% of previously diagnosed papillary renal cell carcinoma (PRCC). Renal papillary adenoma (PA) is suggested to be the precursor of PRCC. This study aimed to investigate the association between PRNRP and PA, particularly the morphologically similar type D PA.

METHODS AND RESULTS

Nephrectomy specimens of PRCC and PA from our 10-year pathology archives were retrieved and reviewed. GATA3 immunohistochemistry and RAS/BRAF testing were performed in all cases reclassified as PRNRP and all PAs with sufficient materials. Overall, PRNRP accounted for 9.1% (10 of 110) of PRCC and there was no recurrence/metastasis with a mean follow-up period of 39 months. Three novel morphological features were described, including clear cell change, mast cell infiltration and metaplastic ossification. Nine of the 10 PRNRPs showed diffuse and strong GATA3 expression and KRAS missense mutations at codon 12. One case exhibited moderate GATA3 staining on 80% of the tumour cells and RAS/BRAF wild-type. In a total of 73 PAs, 11 were classified as type D. GATA3 expression was significantly more frequent in type D versus non-type D PAs (100 versus 35%, P < 0.01). KRAS missense mutations were identified in six of eight (75%) of the type D PAs but none of the 18 non-type D PAs.

CONCLUSIONS

Type D PA was different from other types of PA and represented an analogue or a small-sized PRNRP for their identical morphology, immunophenotype and molecular signature.

Morphological, immunohistochemical, and genomic analyses of papillary renal neoplasm with reverse polarity

Papillary renal neoplasm with reverse polarity (PRNRP) is a recently proposed entity of renal tumor. It shows a far better prognosis than papillary renal cell carcinoma (PRCC) and frequently has KRAS missense mutation. In this study, we compared 14 cases of PRNRP and 10 cases of PRCC type 1 (PRCC1) and type 2 (PRCC2) from clinical, morphological, immunohistochemical, and molecular biological perspectives. We subjected all PRNRP and PRCC cases to immunohistochemical analysis. Whole-exome sequencing using next-generation sequencing (NGS) was performed for six cases of PRNRP, three cases of PRCC1, and four cases of PRCC2. A search for KRAS gene mutation in the remaining eight cases of PRNRP was performed by polymerase chain reaction (PCR) sequencing. The results showed that all cases of PRNRP were pT1N0M0, none of which followed a course of recurrence or tumor-related death. Immunohistochemical analysis revealed diffuse staining of CK7, EMA, PAX8, and GATA3 but weak or negative staining of CD10, CD15, and AMACR in PRNRP. By NGS and PCR, KRAS missense mutation was detected in 11 of 14 PRNRP cases, although pathogenic KRAS mutation was not observed in PRCC1 and PRCC2. NGS analysis revealed less tumor mutation burden in PRNRP than in PRCC. PRNRP also showed no specific chromosomal copy number abnormalities, including gains of 7 and 17. In conclusion, we propose that PRNRP is a distinct condition from PRCC.

Bilateral Nephrectomy for Adult Polycystic Kidney Disease Does Not Affect the Graft Function of Transplant Patients and Does Not Result in Sensitisation

Background

Native nephrectomy in Adult Polycystic Kidney Disease (ADPKD) patients is a major operation with controversy related to timing and indications. We present our single centre experience in transplanted patients and future candidates for transplantation.

Methods

Retrospective analysis from an anonymised database of bilateral nephrectomies for ADPKD patients. Results were reported as median, range, and percentage. Differences between groups were tested using ANOVA and t-test. Surgery was performed between January 2012 and July 2018.

Results

Thirty-three patients underwent bilateral native nephrectomy for APKD. 18 had a functioning kidney transplant (transplant group, 55%) while 15 patients were on dialysis (dialysis group, 45%) at the time of surgery; 8 patients of the latter group (24% of the whole cohort) were eventually transplanted. 53% were males, with median age of 55 years (27-71). Indications to surgery were the following: space (symptoms related to the size of the native kidneys or need to create space for transplantation) (59%), recurrent cyst infection (36%), haematuria (15%), pain (24%), and weight loss associated with cystic alteration on imaging (3%). In the transplant group, postoperative kidney function was not affected; haemoglobin serum levels significantly dropped in the whole cohort: 121 (82-150) g/L, versus 108 (58-154) g/L (p<0.001), with 14 patients being transfused perioperatively. Elevation of anti-HLA antibodies was noted in one female patient on dialysis, with no change in DSA levels and no rejection after transplant for all 26 transplanted patients. Median postoperative length of hospital stay was 9 days (6-71). One patient died (3%) after six months. Median follow-up for the whole cohort was 282 days (13-1834). Histopathological examination revealed incidental renal neoplasms in five cases (15%): 1 pT1a papillary renal cell carcinoma and 4 papillary adenomas.

Conclusions

Native nephrectomy for ADPKD could be safely performed in case of refractory symptoms, suspect of cancer or to create space for transplantation. It does not affect graft function or DSA status of transplanted patients or the prospect of transplantation of those on the waiting list.

Renal adenomatosis

Adenomatosis is a rare lesion of unknown etiology, defined as multiple (usually 5 or more) adenomas in one kidney. A case of renal adenomatosis in a 68-year-old woman treated previously for urolithiasis, who underwent nephrectomy because of the nonfunctional left kidney is reported. Apart from multiple adenomas, numerous hyperplastic lesions involving single tubules were present in the resected kidney. Both adenomas and hyperplastic lesions exhibited the expression of alpha-methylacyl-coenzyme A racemase (AMACR). Renal adenomatosis is worth special attention, since renal papillary adenomas are suggested as precursor lesions of papillary renal cell carcinoma that show similar AMACR expression.

Precursor Lesions of Urologic Malignancies

CONTEXT

- Precursor lesions of urologic malignancies are established histopathologic entities, which are important not only to recognize for clinical purposes, but also to further investigate at the molecular level in order to gain a better understanding of the pathogenesis of these malignancies.

OBJECTIVE

- To provide a brief overview of precursor lesions to the most common malignancies that develop within the genitourinary tract with a focus on their clinical implications, histologic features, and molecular characteristics.

DATA SOURCES

- Literature review from PubMed, urologic pathology textbooks, and the 4th edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs. All photomicrographs were taken from cases seen at Weill Cornell Medicine or from the authors' personal slide collections.

CONCLUSIONS

- The clinical importance and histologic criteria are well established for the known precursor lesions of the most common malignancies throughout the genitourinary tract, but further investigation is warranted at the molecular level to better understand the pathogenesis of these lesions. Such investigation may lead to better risk stratification of patients and potentially novel treatments.

Oncocytic Papillary Renal Cell Carcinoma in the Background of Renal Adenomatosis

Renal adenomatosis is a rare disease characterized by numerous adenomas in bilateral kidneys. A literature review shows that malignant tumors can arise in this condition. The present case describes an oncocytic papillary renal cell carcinoma (PRCC) arising in renal adenomatosis. A 70-year-old man presented with incidentally identified, multiple right renal masses on computed tomography. Right nephrectomy was performed, and the resected kidney revealed numerous radiologically undetected small nodules additionally. Microscopically, the nodules were papillary neoplasms of variable sizes and cytological features. The largest nodule measured 1.6 cm and was composed of oncocytic cells, meeting the diagnostic criteria of oncocytic PRCC. The smaller nodules of papillary adenomas and tiny lesions showing a single papillary ingrowth were also seen. This case exhibits a spectrum of renal papillary neoplasms in a resected kidney and can be a valuable case in the understanding of tumorigenesis.

AMACR Positive Papillary Renal Adenomatosis and Multifocal Papillary Carcinoma in End Stage Renal Disease

Immunomarker α-methylacyl-coenzyme A racemase (AMACR), a protein involved in the metabolism of branched chain fatty acids was initially recognized in the evaluation of prostate cancer. AMACR is also a fairly sensitive marker for papillary renal cell carcinoma. Papillary adenoma associated with papillary renal cell carcinoma are AMACR positive and both represent a continuum of the same biological process. However, the papillary adenomas associated with end-kidney and/or acquired cystic disease are AMACR negative. Herein, we report a case of AMACR positive renal adenomatosis with tiny foci of papillary carcinoma in a background of end stage kidney disease and nephrolithiasis. AMACR staining pattern in renal papillary adenomas needs more evaluation to better understand their pathogenesis under different settings.

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.

Human de novo papillary renal-cell carcinomas in a kidney graft: evidence of recipient origin with adenoma-carcinoma sequence

Papillary renal-cell carcinoma (pRCC) is unusual for its occurrence in kidneys with chronic dysfunction, for its frequent multifocality and for its common association with papillary adenoma, a benign renal lesion morphologically indistinguishable from pRCC. Concomitant development of papillary adenoma and pRCC in five transplanted kidneys, where donor and recipient characteristics are well established, provided a unique opportunity for molecular studies of de novo pRCC carcinogenesis. We aimed to study this tumor type to determine whether or not the different papillary tumors have the same origin, and whether or not papillary adenomas are precursor lesions of pRCC. We performed XY-FISH in sex-mismatched kidney transplants, and polymorphic microsatellite DNA and high-resolution melting of mitochondrial DNA analyzes in all five patients on laser-microdissected tumor cells, then compared these molecular profiles to donor and recipient profiles. This study (i) identified the recipient origin of de novo papillary adenomas and pRCCs in a kidney transplant, (ii) demonstrated an identical origin for precursor cells of papillary adenomas and pRCCs and (iii) showed additional genetic alterations in pRCCs compared to papillary adenomas. This molecular approach of papillary tumors developed in transplanted kidney identified successive steps in carcinogenesis of human de novo papillary renal-cell carcinoma.

Incidentally detected renal adenomatosis in a patient with urolithiasis: a case report

A renal epithelial tumor with a papillary or tubulopapillary pattern and a low nuclear grade is defined as a renal adenoma if its diameter is 5 mm or less. Two important issues related to the renal adenoma are the lack of exact criteria for the histopathological differentiation from a papillary renal cell carcinoma and the lack of consensus as to whether it is a precancerous lesion. Renal adenomatosis is very rarely seen entity entity characterized by multiple and usually bilateral adenomas. Innumerable adenomas, adenomatous transformations within a single tubule and adenomas measuring 7 mm or less, were detected in a 47-year-old man who underwent simple nephrectomy due to nonfunctional hydronephrosis secondary to urolithiasis. In this paper, our diagnostic approach to this fairly rare entity is discussed along with a brief literature review.

Papillary renal cell carcinoma is associated with PTEN hamartoma tumor syndrome

OBJECTIVE

To formally study the prevalence and histologic classification of renal cell carcinoma (RCC) in a series of patients with PTEN hamartoma tumor syndrome (PHTS).

METHODS

We evaluated prevalence of RCC within a prospectively-accrued series of 219 patients found to have pathogenic germline PTEN mutations. Clinical data including pathology reports were requested for all participants. Slides and tumor blocks were requested for central pathology re-review and immunohistochemistry (IHC) analysis.

RESULTS

Nine patients were identified with RCC. Based on Surveillance Epidemiology and End Results (SEER) data 0.28 RCC cases were expected for the group, giving an overall age-adjusted Standardized Incidence Ratio (SIR) of 31.7 (95% CI 15.4-58.1, P < 0.001) with a higher sex-adjusted SIR for females (46.7 vs 21.6 for males). Reported histology of each mutation positive patient's RCC was variable. However, on central pathology re-review of eight patients, six examined lesions were determined to be of papillary subhistology (pRCC), with the other two patients' tumors consistent with the initial report of chromophobe RCC (chRCC). IHC demonstrated complete loss of PTEN protein in all PTEN mutation positive patients' pRCCs and patchy positivity in one chRCC.

CONCLUSION

PHTS is a hereditary syndrome newly associated with pRCC, and PTEN IHC may be a helpful screening tool to identify pRCC patients with PHTS. Physicians caring for PHTS patients should note the >31-fold increased risk for RCC and have a low threshold for investigating possible RCC in patients with relevant complaints. Renal ultrasound is not sensitive for detecting pRCC and so PHTS patients should have alternate renal imaging (CT or MRI).

Native nephrectomy in transplant patients with autosomal dominant polycystic kidney disease

INTRODUCTION

This study examined the clinical indications and timing for native nephrectomy (NN), together with the associated pathological findings in transplant patients with autosomal dominant polycystic kidney disease (ADPKD) at our institute over a period of 20 years.

METHODS

A retrospective review was performed of ADPKD patients who had undergone both kidney transplantation and NN. Patients were identified from the kidney transplant database between 1988 and 2008 at Guy's and St Thomas' Hospital and the notes reviewed. All NN specimens were re-reviewed and reported according to current guidelines.

RESULTS

There were 157 kidney transplants performed for ADPKD (114 cadaveric and 43 living donor). Of these, 31 required NN (28 bilateral). The timing of NN was pre-transplant in 10 cases, at the time of the transplant in 1 case and post-transplant in 20 cases. The indications for NN were urinary tract infection (n=14, 45%), pain (n=12, 39%), tumour suspicion (n=3, 10%), haematuria (n=1, 3%) and space (n=1, 3%). Mortality in this NN series was 3%, with a 65% surgical morbidity rate. The length of hospital stay post-NN was significantly longer with open compared with laparoscopic techniques (p=0.003). There were two renal cell carcinomas (RCCs) in this series. Both patients presented with macroscopic haematuria (bilateral pT1a papillary RCCs in one case and a pT3b clear cell RCC in the other case). The incidence of RCC in this series of ADPKD transplant patients was 1.3%.

CONCLUSIONS

We have demonstrated that the majority of ADPKD patients do not require NN, with only 20% of our series undergoing this procedure. The timing of NN is variable and dictated by indication. NN was only required to make space for transplantation in one case (combined kidney and pancreas transplant). The main indications for NN were recurrent infection and pain, where NN can provide a successful outcome. Laparoscopic NN can be performed safely in patients with ADPKD. Haematuria in such patients should not be assumed to be of benign origin and requires exclusion of urinary tract malignancy as the incidence of RCC in this population is at least as common as in the general population.

Isolation and characterization of progenitor-like cells from human renal proximal tubules

The tubules of the kidney display a remarkable capacity for self-renewal on damage. Whether this regeneration is mediated by dedifferentiating surviving cells or, as recently suggested, by stem cells has not been unequivocally settled. Herein, we demonstrate that aldehyde dehydrogenase (ALDH) activity may be used for isolation of cells with progenitor characteristics from adult human renal cortical tissue. Gene expression profiling of the isolated ALDH(high) and ALDH(low) cell fractions followed by immunohistochemical interrogation of renal tissues enabled us to delineate a tentative progenitor cell population scattered through the proximal tubules (PTs). These cells expressed CD24 and CD133, previously described markers for renal progenitors of Bowman's capsule. Furthermore, we show that the PT cells, and the glomerular progenitors, are positive for KRT7, KRT19, BCL2, and vimentin. In addition, tubular epithelium regenerating on acute tubular necrosis displayed long stretches of CD133(+)/VIM(+) cells, further substantiating that these cells may represent a progenitor cell population. Furthermore, a potential association of these progenitor cells with papillary renal cell carcinoma was discovered. Taken together, our data demonstrate the presence of a previously unappreciated subset of the PT cells that may be endowed with a more robust phenotype, allowing increased resistance to acute renal injury, enabling rapid repopulation of the tubules.

Reduced Notch signaling leads to renal cysts and papillary microadenomas

The formation of proximal nephron segments requires canonical Notch2 signaling, but other functions of Notch signaling during renal development are incompletely understood. Here, we report that proximal tubules forming with reduced Notch signaling, resulting from delayed conditional inactivation of Notch1 and/or Notch2, are prone to cyst formation and tubular epithelial stratification. Conditional inactivation of the DNA binding factor RBP-J, which mediates Notch signaling, also resulted in multiple congenital cysts arising from the proximal tubule. Moreover, a few stratified foci/microadenomas containing hyperproliferative cells, resembling precursors of papillary renal cell carcinoma, formed in these proximal tubules. Epithelial stratification correlated neither with reduced expression of the transcriptional regulator of ciliary proteins TCF2/HNF1beta nor with loss of apical-basal polarity. Instead, Notch signaling helped to restrict the orientation of epithelial mitotic spindles to a plane parallel to the basement membrane during nephron elongation. In the absence of Notch, random spindle orientation may explain the epithelial stratification and cyst formation. Furthermore, post hoc analysis of human class 1 papillary renal cell carcinoma revealed reduced Notch activity in these tumors, resulting from abundant expression of a potent inhibitor of canonical Notch signaling, KyoT3/FHL1B. In summary, these data suggest that canonical Notch signaling maintains the alignment of cell division in the proximal tubules during nephrogenesis and that perturbations in Notch signaling may lead to cystic renal disease and tumorigenesis.

Renal cell carcinoma in patients with end-stage renal disease: relationship between histological type and duration of dialysis

OBJECTIVE

To evaluate the clinical outcomes and histological types of renal cell carcinoma (RCC) arising in patients with end-stage renal disease (ESRD), and to analyse the relationship of histopathological features with the duration of dialysis.

PATIENTS AND METHODS

Clinical characteristics and outcomes of 34 patients who had a radical nephrectomy for RCC arising in ESRD between November 1994 and June 2008 were investigated. Archive paraffin-embedded tissue specimens obtained from 27 patients were histochemically and immunohistochemically analysed to determine the histopathological type.

RESULTS

There was one death from cancer and one patient with local progression within a median observation period of 29.5 months. Acquired cystic disease (ACD)-associated RCC, clear cell-papillary RCC, mucinous tubular and spindle-cell carcinoma, and Xp11.2 translocation/TFE3 gene fusion were identified in eight, two, three and one patient, respectively. Conventional clear-cell RCC was the predominant histological type (nine of 15) in patients with a duration of dialysis of <10 years, while ACD-associated RCC was predominant (seven of 12) in those with dialysis for > or =10 years. Sarcomatoid foci were identified in three patients with dialysis for > or =10 years. Papillary adenoma was microscopically identified as a satellite tumour in 10 patients.

CONCLUSION

The spectrum of histological types of RCCs arising in ESRD is distinct from that of sporadic RCCs. Patients with a longer duration of dialysis should have particular attention for progression and metastasis. Immunohistochemical profiling is efficient in the histological classification of RCCs arising in ESRD, although knowledge about genetic changes remains to be accumulated.

Prevalence of renal cell carcinoma in patients with autosomal dominant polycystic kidney disease and chronic renal failure

OBJECTIVES

To study the prevalence and the characteristics of renal cell carcinoma (RCC) in patients with autosomal dominant polycystic kidney disease (ADPKD) in our series.

METHODS

We reviewed retrospectively all the nephrectomies performed in our department between 1982 and 2003 in patients with ADPKD and chronic renal failure.

RESULTS

Seventy-nine patients (42 males and 37 females) with ADPKD and chronic renal failure underwent 89 nephrectomies; in 10 of 79, both kidneys were removed but not simultaneously. Mean age was 50.4 years (range, 32-69 years). Of 79 patients, 50 had end-stage renal disease (ESRD) and were on hemodialysis or had received a transplant for >1 year. On histologic examination, 11 of 89 kidneys were diagnosed with carcinomas. There was 1 patient with bilateral tumor (tubulopapillary Ca) and 3 kidneys (27.3%) with multifocal tumors. Regarding the histologic type, there were 7 of 12 (58.3%) clear cell carcinomas and the remaining 5 (41.7%) were tubulopapillary carcinomas.

CONCLUSIONS

The prevalence of RCC was higher in patients with ADPKD and ESRD, with >1 year on dialysis or renal transplantation undergoing nephrectomy according the protocol. It would be 2 to 3 times more frequent than RCC in patients with ESRD alone. The clinician should maintain a high alert of suspicion for RCC in such patients.

Antiproliferative effects of essential oils and their major constituents in human renal adenocarcinoma and amelanotic melanoma cells

OBJECTIVES

The purpose of this study was to evaluate cytotoxic activity of Platycladus orientalis, Prangos asperula and Cupressus sempervirens ssp. pyramidalis essential oils and to identify active components involved in inhibition of population growth of human cancer cell lines.

MATERIALS AND METHODS

Essential oils were obtained by hydrodistillation and were analysed by gas chromatography and gas chromatography coupled to mass spectrometry. Antiproliferative activity was tested on amelanotic melanoma C32 cells and on renal cell adenocarcinoma cells, using the sulphorhodamine B assay.

RESULTS

Cupressus sempervirens ssp. pyramidalis leaf oil exerted the highest cytotoxic activity with an IC(50)value of 104.90 microg/mL against C32, followed by activity of P. orientalis and P. asperula on the renal adenocarcinoma cell line (IC(50) of 121.93 and 139.17 microg/mL, respectively). P. orientalis essential oil was also active against amelanotic melanoma with an IC(50) of 330.04 microg/mL. Three identified terpenes, linalool, beta-caryophyllene and alpha-cedrol, were found to be active on both cell lines tested.

CONCLUSIONS

Our findings provide novel insights into the field of cytotoxic properties of essential oils. This study provided evidence on how cytotoxic activity of the oils is not always related to their major constituents, except for lower activity found in both cell lines for alpha-cedrol. Interestingly, beta-caryophyllene and linalool exhibited comparable IC(50) values to the commercial drug vinblastine on the ACHN cell line. This opens a new field of investigation to discover mechanisms responsible for the observed activity.

Renal adenomas: pathological differential diagnosis with malignant tumors

The renal adenomas can be confused by imaging diagnosis with malignant renal tumors, but there are also real biological dilemmas to determine their behavior. The consensus decisions are the following. (1) The adenoma of clear cells is not accepted, instead it is considered that all the clear-cell tumors are carcinomas, with greater or lesser aggressiveness. (2) Among the papillary neoplasms the WHO 2004 renal cell tumors classification are considered as papillary adenomas tumors with a maximum diameter of 5 mm and may represent a continuum biological process to papillary renal cell carcinoma. The papillary adenomas associated with End-kidney and/or acquired cystic disease may have a different pathogenesis. (3) To consider a tumor as an oncocytoma the size is not important, only the cytological features, microscopic, ultrastructural, and immunohistochemically can help, but some chromosomal observations introduce some questions about its relation with the chromophobe renal cell carcinoma. (4) Finally, the metanephric adenoma, a tumor with some morphological similarity with the nephroblastoma must be considered in the renal adenomas diagnosis.

Characterization of the renal cyst fluid proteome in autosomal dominant polycystic kidney disease (ADPKD) patients

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by localized autonomous cellular proliferation, fluid accumulation within the cysts, and intraparenchymal fibrosis of the kidney. Little is known about the cyst fluid's protein composition. We hypothesized that the complex collection of cyst fluid proteins (cyst fluid proteome) plays a major role in cyst formation/maintenance and contains yet unknown diagnostic and mechanistic features that are common to all forms of PKD. We analyzed five kidney cyst fluids from four patients with ADPKD. Tryptic peptides from plasma-protein immunodepleted (ProteoPrep(R)) and undepleted cyst fluid samples were analyzed by LC-MS/MS. Proteins were identified by SEQUEST and validated via the Trans-Proteomic Pipeline; 391 proteins were identified with >90% confidence; 251 of them in undepleted and 362 in immunodepleted samples. Immunodepletion removed >94% of the cyst fluid protein. A surprisingly large and functionally diverse number of proteins common to most cysts were identified. These proteins may be of mechanistic interest and include Ig gamma, kappa, and fragments; complement components; vitronectin; orosomucoid; prostaglandin D2 synthase; vitamin D-binding protein; clusterin; SERPIN family proteins; hemopexin; and fetuin-A. Additionally, these results suggest that further prefractionation and enhanced chromatographic separation of tryptic peptides is likely to expose an even greater number of relevant proteins.

Diffuse minute clear cell proliferation in kidney: case report and review of literature

To our knowledge, diffuse involvement of renal parenchyma by multiple minute foci of clear cell proliferations has not been previously reported. We report such a case, found incidentally, in an 86-year-old woman who had undergone right ureteronephrectomy for pyeloureteral urothelial carcinoma. Macroscopy of the kidney showed numerous yellow dot-like cortical nodules less than 0.3 cm. Histologic examination of the kidney and nodules revealed innumerable foci of minute clear cell proliferations in a background of chronic pyelonephritis. The benign or malignant nature of those clear cell microtumors was investigated by immunohistochemistry and fluorescent in situ hybridization analysis of chromosome 3p.

Tubulocystic carcinoma of the kidney: clinicopathologic and molecular characterization

The nature of tubulocystic carcinoma, a rare renal tumor composed of tubular and cystic structures, is poorly understood. It has been suggested that it may represent a low-grade collecting duct carcinoma of the kidney despite the lack of sufficient molecular and pathologic evidence. The aim of this study was to examine the clinical and pathologic features of 13 cases of tubulocystic carcinoma of the kidney. Furthermore, using gene expression microarray analysis, we defined the molecular signature of this tumor by comparing it with other renal tumors in our previously established molecular profile database. Histologically, all 13 tumors were composed of closely packed tubules and cysts of varying sizes separated by fibrovascular septa. The epithelial lining cells of the tubules and cysts in this tumor were characterized by abundant eosinophilic cytoplasm with prominent nucleoli often showing a hobnail appearance. Clinically, one of the 13 cases showed metastasis to the pelvic lymph nodes. Five of the 13 cases coexisted with papillary renal cell carcinoma (RCC) (n=3) or papillary adenoma (n=2). In addition, the molecular profile of tubulocystic carcinoma was similar but not identical to those of papillary RCC by clustering analysis. Through comparative genomic microarray analysis, tubulocystic carcinoma showed gains of chromosome 17, but not chromosome 7, whereas most papillary RCCs showed chromosomal gains in both 7 and 17 (trisomies). Therefore, based on its unique pathologic features and molecular signature as well as its biologic behavior to develop metastasis either by itself or in association with papillary RCC, tubulocystic carcinoma of the kidney should be recognized as a distinct subtype of RCC and be distinguished from other malignant and benign cystic lesions of the kidney.

Huge renal cyst with parietal renal cell carcinoma, osseous metaplasia and a papillary adenoma: a case report with unique clinicopathological features and literature review

The unique clinicopathological features of a giant solitary renal cyst with a parietal clear cell carcinoma in contiguity with a focus of osseous metaplasia and a papillary adenoma are reported. Ultrasonography and computed tomography showed a single cyst with a focal wall irregularity. During surgery, a frozen section revealed the presence of a renal cell carcinoma of clear cell type, so a nephrectomy was performed. After extensive pathological sampling of the cyst's wall, a focus of osseous metaplasia in contiguity with the main tumour and a microscopic papillary adenoma were found. Diagnostic implications for the present case are discussed within a pertinent literature review.