Hereditary renal cancers

ERN GENTURIS clinical practice guidelines for the diagnosis, surveillance and management of people with Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé syndrome (BHD syndrome) is an autosomal dominant multisystem disorder with variable expression due to pathogenic constitutional variants in the FLCN gene. Patients with BHD syndrome are predisposed to benign cutaneous fibrofolliculomas/trichodischomas, pulmonary cysts with an associated risk of spontaneous pneumothorax, and renal cell carcinoma. A requirement for updated International consensus recommendations for the diagnosis and management of BHD syndrome was identified. Based on a comprehensive literature review and expert consensus within the fields of respiratory medicine, urology, radiology, dermatology, clinical oncology and clinical genetics, updated recommendations for diagnosis, surveillance and management in BHD syndrome were developed. With the widespread availability of FLCN genetic testing, clinical scenarios in which a diagnosis should be considered and criteria for genetic testing were defined. Following a clinical and/or molecular diagnosis of BHD syndrome, a multidisciplinary approach to disease management is required. Regular renal cancer surveillance is recommended in adulthood and life-long, but the evidence base for additional tumour surveillance is limited and further research warranted. Recommendations for the treatment of cutaneous, pulmonary and renal manifestations are provided. Awareness of BHD syndrome needs to be raised and better knowledge of the clinical settings in which the diagnosis should be considered should enable earlier diagnosis. Further details, including areas for future research topics are available at: https://www.genturis.eu/l=eng/Guidelines-and-pathways/Clinical-practice-guidelines.html .

Predominantly multiple focal non-cystic renal lesions: an imaging approach

Multiple non-cystic renal lesions are occasionally discovered during imaging for various reasons and poses a diagnostic challenge to the practicing radiologist. These lesions may appear as a primary or dominant imaging finding or may be an additional abnormality in the setting of multiorgan involvement. Awareness of the imaging appearance of the various entities presenting as renal lesions integrated with associated extrarenal imaging findings along with clinical information is crucial for a proper diagnostic approach and patient work-up. This review summarizes the most relevant causes of infectious, inflammatory, vascular, and neoplastic disorders presenting as predominantly multiple focal non-cystic lesions.

[Genetic diffuse cystic lung disease in adults]

Multiple cystic lung diseases comprise a wide range of various diseases, some of them of genetic origin. Lymphangioleiomyomatosis (LAM) is a disease occurring almost exclusively in women, sporadically or in association with tuberous sclerosis complex (TSC). Patients with LAM present with lymphatic complications, renal angiomyolipomas and cystic lung disease responsible for spontaneous pneumothoraces and progressive respiratory insufficiency. TSC and LAM have been ascribed to mutations in TSC1 or TSC2 genes. Patients with TSC are variably affected by cutaneous, cognitive and neuropsychiatric manifestations, epilepsy, cerebral and renal tumors, usually of benign nature. Birt-Hogg-Dubé syndrome is caused by mutations in FLCN encoding folliculin. This syndrome includes lung cysts of basal predominance, cutaneous fibrofolliculomas and various renal tumors. The main complications are spontaneous pneumothoraces and renal tumors requiring systematic screening. The mammalian target of rapamycin (mTOR) pathway is involved in the pathophysiology of TSC, sporadic LAM and Birt-Hogg-Dubé syndrome. MTOR inhibitors are used in LAM and in TSC while Birt-Hogg-Dubé syndrome does not progress towards chronic respiratory failure. Future challenges in these often under-recognized diseases include the need to reduce the delay to diagnosis, and to develop potentially curative treatments. In France, physicians can seek help from the network of reference centers for the diagnosis and management of rare pulmonary diseases.

Case report: Ultrasonographic findings of retroperitoneum and abdominal wall metastases of renal cell carcinoma with FH gene deletion

Renal cell carcinoma with FH gene deletion is a rare subtype of renal cell carcinoma. There had been few reports about ultrasonographic imaging of metastasis of renal cell carcinoma with FH gene deletion. This case reported one of the features of metastasis of renal cell carcinoma with FH gene deletion of a male patient 7 months after undergoing radical nephrectomy. He was diagnosed with a renal malignant tumor before the operation and confirmed to be primary FH gene-deficient renal cell carcinoma after undergoing radical nephrectomy in another hospital. Reexamination 7 months after the operation indicated that multiple metastases all over the body were found; therefore, he came to our hospital for further diagnosis and therapy. The tumors have metastasized in the lungs, bones, and lymph nodes adjacent to the left reproductive vessels and external iliac vessels, retroperitoneum, and abdominal wall so far as confirmed by PET/CT or MRI. Ultrasonographic findings of masses in the retroperitoneum and abdominal wall are fully discussed, which have been confirmed by biopsy and diagnosed as renal cell carcinoma with FH gene deletion by pathology.

Understanding Mechanisms of RKIP Regulation to Improve the Development of New Diagnostic Tools

Simple Summary

Raf Kinase Inhibitor protein is a protein that governs multiple intracellular signalling involved primarily in the progression of tumours and the development of metastases. In this review, we discussed the main mechanisms that regulate the expression and activity of RKIP with the aim of identifying the link between the transcriptional, post-transcriptional and post-translational events in different tumour settings. We also tried to analyse the studies that have measured the levels of RKIP in biological fluids in order to highlight the possible advantages and potential of RKIP assessment to obtain an accurate diagnosis and prognosis of various tumours.

Abstract

One of the most dangerous aspects of cancer cell biology is their ability to grow, spread and form metastases in the main vital organs. The identification of dysregulated markers that drive intracellular signalling involved in the malignant transformation of neoplastic cells and the understanding of the mechanisms that regulate these processes is undoubtedly a key objective for the development of new and more targeted therapies. RAF-kinase inhibitor protein (RKIP) is an endogenous tumour suppressor protein that affects tumour cell survival, proliferation, and metastasis. RKIP might serve as an early tumour biomarker since it exhibits significantly different expression levels in various cancer histologies and it is often lost during metastatic progression. In this review, we discuss the specific impact of transcriptional, post-transcriptional and post-translational regulation of expression and activation/inhibition of RKIP and focus on those tumours for which experimental data on all these factors are available. In this way, we could select how these processes cooperate with RKIP expression in (1) Lung cancer; (2) Colon cancer, (3) Breast cancer; (4) myeloid neoplasm and Multiple Myeloma, (5) Melanoma and (6) clear cell Renal Cell Carcinoma. Furthermore, since RKIP seems to be a key marker of the development of several tumours and it may be assessed easily in various biological fluids, here we discuss the potential role of RKIP dosing in more accessible biological matrices other than tissues. Moreover, this objective may intercept the still unmet need to identify new and more accurate markers for the early diagnosis and prognosis of many tumours.

Bibliometric Analysis of Birt-Hogg-Dubé Syndrome From 2001 to 2021

Background

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant inherited disorder caused by germline mutations in folliculin (FLCN). Despite our significantly evolved understanding of BHD over the past decades, no bibliometric analyses have been conducted in this field. This study aimed to analyze and visualize the characteristics of publication outputs, the research hotspots, and scientific frontiers about BHD using bibliometric analysis.

Methods

All relevant literature on BHD was culled from the Web of Science Core Collection (WoSCC) database. Valid data were extracted from the articles and visually analyzed using CiteSpace and VOSviewer.

Results

A total of 751 qualifying papers were included. Publication outputs concerning BHD increased over time. The dominant position of the United States and Japan in BHD research field was evident. National Cancer Institute (the USA) and Yokohama City University (Japan) were the two most productive organizations. W. Marston Linehan exerted a considerable publication impact and had made the most remarkable contributions in the field of BHD. Plos One was the journal with the highest publication outputs, and half of the top 10 journals and co-cited journals belonged to Q1 or Q2. Keyword citation bursts revealed that management, tumor suppressor, flcn gene, spectrum, diagnosis, risk, computed tomography were the emerging research hotspots.

Conclusion

Research on BHD is prosperous. International cooperation between countries and organizations is also expected to deepen and strengthen in the future. Our results indicated that FLCN-associated pathways involved in the pathogenesis of BHD, specific options for early diagnosis, and molecular-targeting therapies will remain research hotspots in the future.

Tuberous Sclerosis Complex (TSC): Renal and Extrarenal Imaging

Tuberous sclerosis complex is a multiorgan syndrome manifesting with several benign and malignant tumors. Complications arising from renal abnormalities are a leading cause of death in patients with tuberous sclerosis complex. Renal cell carcinoma is relatively uncommon, occurring in 2%-4% of patients with tuberous sclerosis complex syndrome, but nonetheless can significantly contribute to morbidity and mortality. Extrarenal manifestations of tuberous sclerosis complex, including within the chest, abdomen and central nervous system, aid in diagnosis. Pathogenesis and management are also discussed, including the importance of the types of renal masses found in these patients.

Kidney Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Kidney Cancer focus on the screening, diagnosis, staging, treatment, and management of renal cell carcinoma (RCC). Patients with relapsed or stage IV RCC typically undergo surgery and/or receive systemic therapy. Tumor histology and risk stratification of patients is important in therapy selection. The NCCN Guidelines for Kidney Cancer stratify treatment recommendations by histology; recommendations for first-line treatment of ccRCC are also stratified by risk group. To further guide management of advanced RCC, the NCCN Kidney Cancer Panel has categorized all systemic kidney cancer therapy regimens as "Preferred," "Other Recommended Regimens," or "Useful in Certain Circumstances." This categorization provides guidance on treatment selection by considering the efficacy, safety, evidence, and other factors that play a role in treatment selection. These factors include pre-existing comorbidities, nature of the disease, and in some cases consideration of access to agents. This article summarizes surgical and systemic therapy recommendations for patients with relapsed or stage IV RCC.

[Hereditary kidney cancer - easily clarified and diagnosed with ToSCaNA]

BACKGROUND

In recent years great improvements in the diagnosis and differentiation of hereditary syndroms with predisposition for kidney cancer have been achieved. It has been assumed that 5-8% of all kidney cancer have a hereditary origin. In reality, this number will probably be much higher as many genetic aspects of kidney cancer are still not entirely known. Hereditary kidney cancer usually shows two characteristic properties: While the median age of diagnosis of sporadic renal cell carcinoma is 64 years, patients with a hereditary tumor predisposition are about 20 years younger at the time of diagnosis. Additionally, their tumors often occur multifocal/bilateral. Therefore, a special management with extended diagnostics is necessary for these young kidney cancer patients. In literature many reports on hereditary syndromes with kidney cancer predisposition exist. Though, these papers usually put their focus on single syndromes rather than on the aspects of kidney cancer. The goal of this article is to present the practicing urologist with a compact overview of the most important hereditary syndromes with kidney cancer predisposition and by this improve the primary diagnostic and treatment of renal cancer patients and their relatives.

MATERIAL/METHODS

We conducted a literature search on the five most important hereditary syndromes with kidney cancer association and summarized the results in a chart. Additionally, we formed the acronym ToSCaNA combining the most important extrarenal manifestations of the syndromes. Based on this data, a diagnostic workflow and treatment path was established.

RESULTS

All in all, hereditary kidney cancer is a rare entity, which nonetheless could present as a significant number in high-volume centers. For doctors who scarcely get in contact with these types of tumors, the acronym and workflow could pose a valuable asset for their clinical diagnostic portfolio. An early identification and diagnostic work-up of affected patients and their relatives is crucial for appropriate treatment and surveillance and allows the identification/treatment of additionally affected relatives.

CONCLUSION

In patients with young age of onset and multifocal/bilateral occurrence of kidney cancer, hereditary syndromes should always be considered. The initial suspicion of a hereditary genesis of the cancer can be further evaluated by the acronym ToSCaNA and the presented workflow.

A case of bilateral renal oncocytomas in the setting of Birt-Hogg-Dube syndrome

Birt-Hogg-Dube syndrome is a rare autosomal dominant disorder characterized by pulmonary cysts, renal tumors, and dermal lesions. This syndrome results from a mutation in the gene folliculin, located on chromosome 17p11.2. Herein, a case is described in which the presence of bilateral renal oncocytomas led to the diagnosis of Birt-Hogg-Dube syndrome via an interdisciplinary effort by radiology, pathology, and primary care medicine. No radiographic features alone are sufficient to confirm the diagnosis of Birt-Hogg-Dube. A high index of suspicion must be maintained by both the pathologist and radiologist in the appropriate clinical setting.

Imaging features of fumarate hydratase-deficient renal cell carcinomas: a retrospective study

Backgound

Fumarate hydratase-deficient renal cell carcinoma (FH-RCC) is a subtype of RCC that is increasingly recognized pathologically. The aim of this study was to evaluate the imaging features of FH-RCC on computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG PET), and to determine the pre-operative diagnostic potential of imaging.

Methods

This single-site retrospective study included patients with histologically confirmed FH-RCC or with a renal cancer and known germline FH mutation; imaging of the renal mass before treatment with contrast-enhanced CT, contrast-enhanced MRI, or FDG PET/CT between October 2007 and May 2019. Clinical information, pathological data, and imaging features were analyzed and reported descriptively.

Results

Sixteen patients with sixteen tumors were included (median age 46 years, interquartile range 38–53 years; 31 % female). Almost all tumors were unifocal (15/16, 94 %). Most tumors had infiltrative margins (14/16, 88 %); few were circumscribed (2/16, 12 %). A large cystic tumor component (> 75 % of tumor volume) was seen in 8/16 (50 %) of tumors. Involvement of renal sinus fat was seen in 13/16 (81 %) of tumors, involvement of the hilar collecting system in 8/16 (50 %), and renal vein tumor thrombus in 6/16 (38 %). All 12 tumors (100 %) imaged with MRI had heterogenous tumor enhancement and heterogenous T2 signal. Of those patients that had diffusion-weighted imaging, 11/11 (100 %) of tumors had diffusion restriction in the solid portions of the tumor. Of the patients who had PET, 3/3 (100 %) tumors showed high metabolic activity with mean maximum standardized uptake value (SUV_max) of 16.4 (range 9.6–21.9). Patients presented with retroperitoneal nodal metastases in 69 % of cases and distant metastases in 75 %. Of those four patients without metastatic disease at presentation, three (75 %) developed metastases within 4 years of diagnosis.

Conclusions

In our study, the majority of tumors (≥ 75 %) were unifocal, had an infiltrative margin, invaded the renal sinus fat, and presented with distant metastases. On MRI, most tumors had heterogenous T2 signal and diffusion restriction in their solid components. The small number of cases that had PET imaging showed high metabolic activity.

Using Data from a Sickness Fund Claims Database to Assess the Treatment Patterns and Healthcare Resource Utilization among Patients with Metastatic Renal Cell Carcinoma in Germany

OBJECTIVES

To characterize real-world prescribing patterns and their clinical and healthcare resource utilization (HRU) implications in patients with metastatic renal cell carcinoma (mRCC) treated in Germany.

METHODS

Eligible individuals were enrolled in the "Bundesverband der Betriebskrankenkassen" claims database and received targeted mRCC therapy between 1 January 2008 and 31 December 2016. Prescribing patterns and HRU were characterized by treatment line and summarized by descriptive statistics. Proxy progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier curves.

RESULTS

536 patients receiving mRCC treatment were included. The median treatment duration was 4.2 months (interquartile range [IQR]: 1.7-9.3) for first-line therapy and 3.8 months (IQR: 1.7-9.1) for second-line therapy. Median PFS and OS estimates were similar for the first- and second-line treatments: PFS, 7.4 versus 7.2 months; OS, 14.9 versus 13.6 months. Mean HRU costs were higher for patients receiving first-line therapy (€7,253.2) compared with those receiving second-line therapy (€6,242.9). Exploratory stratification of outcomes by centre expertise suggested a possible trend towards improved OS in the 10 most experienced centres versus all -others: first-line, 18.4 versus 13.2 months; second-line, 16.4 versus 12.4 months.

CONCLUSIONS

In routine care, German clinicians make rational prescribing decisions; possible variations in outcomes between centres warrant further investigation.

Update on Hereditary Renal Cancer and Imaging Implications

Up to 8% of renal cancers are thought to have a hereditary component. Several hereditary renal cancer syndromes have been identified over the last few decades. It is important for the radiologist to be aware of findings associated with hereditary renal cancer syndromes to detect tumors early, enroll patients in appropriate surveillance programs, and improve outcomes for the patient and affected family members. This review discusses from a radiologist's perspective well-known hereditary renal cancer syndromes and emerging genetic mutations associated with renal cancer that are less well characterized, focusing on imaging features and known associations.

Birt-Hogg-Dubé syndrome presenting with spontaneous pneumothorax and extensive pulmonary cysts in the absence of skin lesions or renal pathology

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition which classically manifests with skin lesions such as fibrofolliculomas, pulmonary cysts that predispose to spontaneous pneumothorax and an increased risk of developing renal cell carcinoma. We describe the case of a patient who presented with a spontaneous pneumothorax on a background of multiple lung cysts, in the absence of cutaneous fibrofolliculomas and renal tumours. A germline mutation in the folliculin FLCN gene was subsequently identified, confirming BHD syndrome. Our case highlights the importance of considering a broad differential diagnosis for the cause of a spontaneous pneumothorax in the presence of unexplained cystic lung disease and emphasises the value of maintaining a high index of clinical suspicion for inherited causes of pneumothoraces.

The Relevance of Family History Taking in the Detection and Management of Birt-Hogg-Dubé Syndrome

BACKGROUND

Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal-dominant inherited disorder characterized by inactivation of the gene Folliculin (FLCN), pulmonary cysts with recurrent spontaneous pneumothorax, dermatological lesions, and an increased risk of developing renal malignancies.

OBJECTIVES

We aimed to investigate the real prevalence of BHDS and its prevalence among patients with a familial history of pneumothorax.

METHODS

From July 2014 to December 2016, we consecutively studied all patients with spontaneous pneumothorax and a positive family history for the same condition referring to our Institution. The suspicious cases underwent genetic analysis of the BHDS-causative gene FLCN. FLCN-positive cases were further evaluated with routine blood tests, chest radiography, chest CT, abdominal MRI, and dermatological evaluation.

RESULTS

Among 114 patients admitted with spontaneous pneumothorax, 7 patients had a family history of pneumothorax, and 6/7 (85.7%) patients had positive genetic test for FLCN as well as 7/13 family members. Pulmonary cysts were found in all patients with a FLCN-positive genetic test. Most patients (10/13, 76.9%) had tiny pulmonary cysts less than 1 cm in diameter. The vast majority of cysts were intraparenchymal (12/13, 92.3%) and located in lower lobes. Dermatological lesions were found in 7/13 (54%) patients, renal cysts in 4/13 (31%) patients, and renal cancer in 1 (1/13, 7.7%) patient.

CONCLUSIONS

Although BHDS is considered a rare disease, BHDS underlies spontaneous pneumothorax more often than usually believed, especially whenever a family history of pneumothorax is present. Diagnosis of BHDS is essential to start monitoring patients for the risk of developing renal malignancies.

Cost-Effectiveness Analysis of Treatment for Metastatic Renal Carcinoma in Romania

Rationale: In recent years, the cost of several treatment options for renal cancer have been supported by the Romanian healthcare system for both first- and second-line therapies. First-line alternatives through real-life efficacy and amplitude of adverse reactions may influence the efficacy and costs of patients treated with second-line treatment.

Objective: Estimation of the cost-effectiveness and cost-benefit ratio for first-line treatment alternatives: Sunitinib and Pazopanib from the payer’s perspective in the Romanian healthcare system.

Methods and Results: We developed a Markov model to calculate the cost-effectiveness and cost-benefit ratio for 2 cohorts of patients using the results from the COMPARZ study for efficacy (progression-free survival, general survivability and quality of life) and safety and costs from national hospital databases. For an estimated population of 800 patients, Pazopanib has a quantified benefit of 7.19 years in progression-free survival, 11.71 life years gained and 8.97 years of quality-adjusted life-years compared to Sunitinib. The analysis is limited by the accuracy of the national data used and the transposition of general data on efficacy and safety at the local level.

Physiological and pathological levels of prostaglandin E2 in renal parenchyma and neoplastic renal tissue

Prostaglandin (PG)E₂ seems to promote tumor proliferation by regulating cell growth, inhibiting apoptosis, promoting angiogenesis, and suppressing host immune surveillance of cancer cells. The suppression of prostaglandins biosynthesis is thought to be the main molecular mechanism for non-steroidal anti-inflammatory drugs antineoplastic effect. Yet the relationship between PGE₂ and human renal cell carcinoma remains unclear. The aim of our study is to evaluate the PGE₂ content in human renal parenchyma and Renal Cell Carcinoma. The study was conducted on 20 consecutive patients undergoing radical nephrectomy for Renal Cell Carcinoma. In the normal renal parenchyma and in the neoplastic renal tissue the PGE₂ level was 83.43 ± 5.89 pg/mg and 289.67 ± 22.2 pg/mg, respectively (P < 0.0001). There was no relationship between PGE₂ content and Renal Cell Carcinoma dimension, Fuhrman grade, pathological-Tumor-Node and Metastasis (pTNM) stage and histological subtype. The PGE₂ over-content in neoplastic renal tissue suggests a role of PGE₂ in development and progression of renal carcinoma.

Kidney cancer characteristics and genotype-phenotype-correlations in Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé syndrome (BHDS) is a genetic tumor syndrome characterized by lung cysts, pneumothorax, fibrofolliculomas and renal cell cancer. The diagnosis of BHDS is usually considered if kidney cancer occurs before age 50 years, is multifocal and/or bilateral or of the oncocytoma/hybrid oncocytoma-chromophobe type. Using a sample of 50 BHDS families with a total of 178 patients we analyzed how many kidney cancer patients fulfilled one or more of these criteria. Furthermore, we addressed the question if genotype-phenotype-correlations exist that can be used for risk stratification. Renal cell cancer occurred in 34/178 (19.1%) patients, and the reported male bias was not observed. Furthermore, most kidney malignancies occurred after the age of 50 years. Thus, the majority of tumors did not show the typical hallmarks of BHDS. A below-average tumor frequency (17.2%) was observed for the known mutational hotspot c.1285delC/dupC that was the cause of BHDS in 24% of families. Unexpected was the high tumor frequency (66.7%) associated with mutation c.887C>G within a single family, a finding that merits further exploration.

Renal capsule metastasis from renal pelvic cancer: a case report

Background

Metastatic renal cancers are relatively common. Most are metastases to the renal parenchyma via a hematogenous route and are derived from lung, breast, and gastrointestinal cancer, malignant melanoma, and hematologic malignant cancer. However, little is known about renal capsule metastasis from other cancers.

Case presentation

We report a 71-year-old woman with breast cancer who was treated with endocrine therapy. She presented with gross hematuria and was diagnosed as having right renal pelvic cancer and renal cell cancer. She underwent right laparoscopic radical nephroureterectomy. Pathological findings revealed right pelvic cancer and renal capsule metastasis.

Conclusion

Renal capsule metastasis derived from renal pelvic cancer is very rare. When diagnosing renal capsule cancer, we believe that renal capsule metastasis should also be taken into consideration. Clinical and radiological differential diagnosis of renal capsule metastasis from renal cell cancer and primary renal capsule cancer is difficult. Assessment of the histopathological findings of the surgical specimens seems to be the only realistic approach to achieving the correct diagnosis.

The ABCs of BHD: An In-Depth Review of Birt-Hogg-Dubé Syndrome

OBJECTIVE

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant inherited syndrome involving multiple organs. In young patients, renal neoplasms that are multiple, bilateral, or both, such as oncocytomas, chromophobe renal cell carcinoma (RCC), hybrid chromophobe RCC-oncocytomas, clear cell RCC, and papillary RCC, can suggest BHD syndrome. Extrarenal findings, including dermal lesions, pulmonary cysts, and spontaneous pneumothoraces, also aid in diagnosis.

CONCLUSION

Radiologists may be one of the first medical specialists to suggest the diagnosis of BHD syndrome. Knowledge of pathogenesis and management, including the importance of the types of renal neoplasms in a given patient, is needed to properly recognize this rare condition.

Radiological diagnosis of perinephric pathology: pictorial essay 2015

The perinephric space, shaped as an inverted cone, sits between the anterior and posterior renal fasciae. It can play host to a variety of clinical conditions encountered daily in the reporting schedule for a radiologist. Lesions may be classified and diagnosed based on their imaging characteristics, location and distribution. A broad range of differential diagnoses can be attributed to pathology sitting within this space, often without clinical signs or symptoms. An understanding of commonly encountered conditions affecting the perinephric space, along with characteristic imaging findings, can illustrate and often narrow the likely diagnosis. The aim of this essay is to describe commonly encountered neoplastic and non-neoplastic entities involving the perinephric space and to describe their key imaging characteristics.

TEACHING POINT

• Despite often a bulky disease, perinephric lymphoma does not produce obstruction or stenosis. • In primarily fatty masses, defects within the renal capsule likely represent angiomyolipoma. • Consider paraganglioma if biopsy is planned; biopsy may lead to catecholamine crisis.

Mouse Models of Human Familial Cancer Syndromes

As many as 5% of human cancers appear to be of hereditable etiology. Of the more than 50 characterized familial cancer syndromes, most involve disease affecting multiple organs and many can be traced to one or more abnormalities in specific genes. Studying these syndromes in humans is a difficult task, especially when it comes to genes that may manifest themselves early in gestation. It has been made somewhat easier with the development of genetically engineered mice (GEM) that phenotypically mimic many of these inheritable human cancers. The past 15 years has seen the establishment of mouse lines heterozygous or homozygous null for genes known or suspected of being involved in human cancer syndromes, including APC, ATM, BLM, BRCA1, BRCA2, LKB1, MEN1, MLH, MSH, NF1, TP53, PTEN, RB1, TSC1, TSC2, VHL, and XPA. These lines not only provide models for clinical disease and pathology, but also provide avenues to investigate molecular pathology, gene-gene and protein-tissue interaction, and, ultimately, therapeutic intervention. Possibly of even greater importance, they provide a means of looking at placental and fetal tissues, where genetic abnormalities are often first detected and where they may be most easily corrected. We will review these mouse models, examine their usefulness in medical research, and furnish sources of animals and references.

Epidemiology of Renal Cell Carcinoma

The increasing incidence of RCC in most populations may in part be due to increasing numbers of incidentally detected cancers with new imaging methods. Further, the increase is not only limited to small local tumours but also includes more advanced tumours, which may to some part explain the still high mortality rates. The variation in incidence between populations may have several other explanations. Traditionally the starting point has included thoughts of environmental exposures, which so far have only in part explained the causes of RCC, by means of cigarette smoking and obesity, which may account for approximately 40% of cases in high-risk countries (Table 2). Further, the genetic variations may be of importance as a cause of the difference between populations. Continued research in RCC is needed with the knowledge that nearly 50% of patients die within 5 years after diagnosis. The further search for environmental exposures should take in account the knowledge that RCC consists of different types with specific genetic molecular characteristics. These genetic alterations have in some cases been suggested to be associated with specific exposures. Furthermore, there might exist a modulating effect of genetic polymorphisms among metabolic activation and detoxification enzymes. Hence, a further understanding of the genetic and molecular processes involved in RCC will hopefully give us a better knowledge how to analyse and interpret exposure associations that have importance for both initiation and progression of RCC.

Hereditary Renal Tumor Syndromes: Update on Diagnosis and Management

Hereditary renal cancers account for approximately 5%-8% of all renal tumors. Over the past 2 decades, a number of syndromes have been identified that predispose patients to early renal cancer development, representing all the major histologic types of tumor pathology. In this article, we describe the current knowledge concerning the cell type, known mechanism of tumor development, other manifestations of the syndrome, imaging findings, genetic screening, and imaging surveillance recommendations for each of the major syndromes associated with hereditary renal cancers.

Genetic predisposition to kidney cancer

Kidney cancer is not a single disease but is made up of a number of different types of cancer classified by histology that are disparate in presentation, clinical course, and genetic basis. Studies of families with inherited renal cell carcinoma (RCC) have provided the basis for our understanding of the causative genes and altered metabolic pathways in renal cancer with different histologies. Von Hippel-Lindau disease was the first renal cancer disorder with a defined genetic basis. Over the next two decades, the genes responsible for a number of other inherited renal cancer syndromes including hereditary papillary renal carcinoma, Birt-Hogg-Dube´syndrome, hereditary leiomyomatosis and renal cell carcinoma, and succinate dehydrogenase-associated renal cancer were identified. Recently, renal cell carcinoma has been confirmed as part of the clinical phenotype in individuals from families with BAP1-associated tumor predisposition syndrome and MiTF-associated cancer syndrome. Here we summarize the clinical characteristics of and causative genes for these and other inherited RCC syndromes, the pathways that are dysregulated when the inherited genes are mutated, and recommended clinical management of patients with these inherited renal cancer syndromes.

Inherited renal carcinomas

Hereditary forms of kidney carcinoma account for 5-8% of all malignant kidney neoplasms. The renal tumors are often multiple and bilateral and occur at an earlier age. Each of the hereditary kidney carcinoma syndromes is associated with specific gene mutations as well as a specific histologic type of kidney carcinoma. The presence of associated extrarenal manifestations may suggest a hereditary kidney cancer syndrome. Radiology is most commonly used to screen and manage patients with hereditary kidney cancer syndromes. This manuscript reviews the clinical and imaging findings of well-defined inherited kidney cancer syndromes including von Hippel-Lindau disease, Birt-Hogg-Dubé syndrome, hereditary papillary renal carcinoma syndrome, hereditary leiomyomatosis and RCC syndrome, tuberous sclerosis complex, and Lynch syndrome.

Outcome of genetic evaluation of patients with kidney cancer referred for suspected hereditary cancer syndromes

OBJECTIVE

To analyze patients with kidney cancer referred for evaluation at a high-volume genetics service at a comprehensive cancer center and identify factors associated with positive tests for hereditary cancer syndromes.

METHODS

A retrospective review of patients referred to the Clinical Genetics Service at Memorial Sloan-Kettering Cancer Center was performed, and patients with a personal history of kidney cancer were identified. Patient and disease characteristics were reviewed. In all, 4 variables including age at diagnosis of kidney tumor, presence of syndromic manifestations, family history of kidney cancer, and number of primary malignancies were evaluated for association with positive test results in 2 groups: patients tested for renal cell carcinoma syndromes and Lynch syndrome. Guidance for genetic testing strategy in patients with kidney cancer is provided.

RESULTS

Between 1999 and 2012, 120 patients with a history of kidney cancer were evaluated by the Clinical Genetics Service. The mean age at kidney cancer diagnosis was 52 years (interquartile range: 42-63), with 57% being women. A family history of kidney cancer was reported by 39 patients (33%). Time between diagnosis of first cancer and genetic consultation was <1 year in 54%, 2 to 5 years in 23%, and>5 years in the remaining 23%. Overall, 95 patients were tested for genetic abnormalities with 27 (28%) testing positive. Testing for renal cell carcinoma (RCC)-related syndromes was performed on 43 patients, with 13 testing positive (30%). Lynch syndrome testing was positive in 9 patients (32%) after 28 were tested. In RCC-associated syndromes, young age of diagnosis was associated with positive test results. Conversely, syndromic manifestations and increasing number of primary malignancies were associated with positive Lynch testing.

CONCLUSIONS

The discovery of inherited kidney cancer syndromes has provided a unique opportunity to identify patients at increased risk for cancer. Factors associated with positive genetic testing are unique to different syndromes. These data suggest that in kidney cancer patients evaluated for hereditary cancer syndromes, young age is associated with diagnosis of RCC syndromes, whereas syndromic manifestations and multiple primaries are found in Lynch syndrome. These results, along with clinical awareness, may be useful for practicing urologists to select patients with kidney cancer to refer for genetic counseling.

Renal cell carcinoma: links and risks

This review provides an overview of the incidence of renal cell carcinoma (RCC) and a summary of the most commonly associated risk factors. A literature review was performed with a focus on recent studies with a high level of evidence (large prospective cohort studies and meta-analyses). The incidence rate of RCC varies globally, with the rate rising rapidly in more developed regions, demonstrating the effects of increased use of diagnostic imaging and prevalence of modifiable risk factors. Based on the current evidence, cigarette smoking, obesity, and hypertension are the most well-established risk factors for sporadic RCC worldwide. Acquired cystic kidney disease is also a significant risk factor, specifically in dialysis patients. There is increasing evidence for an inverse association between RCC risk and moderate alcohol consumption. Certain analgesics and occupational exposure have been linked to an increased risk of RCC, although data are limited. Diets rich in fruits and vegetables may provide a protective effect.

Lipid-poor renal angiomyolipoma: Differentiation from clear cell renal cell carcinoma using wash-in and washout characteristics on contrast-enhanced computed tomography

In the present study, a total of 82 patients (42 men and 40 women; age range, 24-84 years), including 34 patients with lipid-poor renal angiomyolipoma (AML) and 49 with clear cell renal cell carcinoma (RCC), who had undergone multiphase contrast-enhanced computed tomography (CT) (i.e., CT with unenhanced, corticomedullary, nephrographic and 5-min delay phase scanning) were evaluated. The peak enhancement attenuation value, net enhancement attenuation value, enhancement ratio, washout value and washout ratio were calculated to compare the enhancement characteristics between the two diseases. The results revealed that the lipid-poor AMLs had a significantly higher mean attenuation value compared with that of CCRCCs on unenhanced CT scans (37.8 vs. 30.9 HU; Mann-Whitney U test, P=0.003). In addition, significant differences were found between lipid-poor AMLs and CCRCCs with regard to wash-in (Mann-Whitney U test, P=0.001) and enhancement ratios (Mann-Whitney U test, P=0.010) on contrast-enhanced CT scans. A receiver operating characteristic (ROC) analysis revealed an area under the curve (AUC) of 0.722 using wash-in for differentiation between CCRCCs and lipid-poor AMLs. Lipid-poor AMLs exhibited a reduced washout of contrast enhancement (35.8±32.7 HU washout value; 29.4±0.187% washout ratio) compared with that of CCRCCs (48.3±28.4 HU washout value; 35.7±0.148% washout ratio; Mann-Whitney U test, P=0.037 and P=0.204, respectively). The ROC analysis result yielded an AUC of 0.639 for the use of washout to differentiate CCRCCs from lipid-poor AMLs. In summary, a larger wash-in and washout of contrast enhancement is a predictor that a lesion is CCRCC.

The spectrum of nephrocutaneous diseases and associations: Genetic causes of nephrocutaneous disease

There are a significant number of diseases and treatment considerations of considerable importance relating to the skin and renal systems. This emphasizes the need for dermatologists in practice or in clinical training to be aware of these associations. Part I of this 2-part continuing medical education article reviews the genetic syndromes with both renal and cutaneous involvement that are most important for the dermatologist to be able to identify, manage, and appropriately refer to nephrology colleagues. Part II reviews the inflammatory syndromes with relevant renal manifestations and therapeutic agents commonly used by dermatologists that have drug-induced effects on or require close consideration of renal function. In addition, we will likewise review therapeutic agents commonly used by nephrologists that have drug-induced effects on the skin that dermatologists are likely to encounter in clinical practice. In both parts of this continuing medical education article, we discuss diagnosis, management, and appropriate referral to our nephrology colleagues in the context of each nephrocutaneous association. There are a significant number of dermatoses associated with renal abnormalities and disease, emphasizing the need for dermatologists to be keenly aware of their presence in order to avoid overlooking important skin conditions with potentially devastating renal complications. This review discusses important nephrocutaneous disease associations with recommendations for the appropriate urgency of referral to nephrology colleagues for diagnosis, surveillance, and early management of potential renal sequelae.

Recurrent spontaneous pneumothoraces and bullous emphysema. A novel mutation causing Birt-Hogg-Dube syndrome

Birt-Hogg-Dube syndrome (BHDS) is a rare form of classically cystic lung disease that may present with spontaneous pneumothorax. The associated skin manifestations (fibrofolliculomas) are not always present. This article describes a case of spontaneous pneumothorax secondary to bullous emphysema in an otherwise healthy gentleman caused by a novel mutation in the folliculin (FLCN) gene.

CT and MR imaging for evaluation of cystic renal lesions and diseases

Cystic renal lesions are commonly encountered in abdominal imaging. Although most cystic renal lesions are benign simple cysts, complex renal cysts, infectious cystic renal disease, and multifocal cystic renal disease are also common phenomena. The Bosniak classification system provides a useful means of categorizing cystic renal lesions but places less emphasis on their underlying pathophysiology. Cystic renal diseases can be categorized as focal, multifocal, or infectious lesions. Diseases that manifest with focal lesions, such as cystic renal cell carcinoma, mixed epithelial and stromal tumor, and cystic nephroma, are often difficult to differentiate but have differing implications for follow-up after resection. Multifocal cystic renal lesions can be categorized as acquired or heritable. Acquired entities, such as glomerulocystic kidney disease, lithium-induced nephrotoxicity, acquired cystic kidney disease, multicystic dysplastic kidney, and localized cystic renal disease, often have distinct imaging and clinical features that allow definitive diagnosis. Heritable diseases, such as autosomal dominant polycystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis, are usually easily identified and have various implications for patient management. Infectious diseases have varied imaging appearances, and the possibility of infection must not be overlooked when assessing a cystic renal lesion. A thorough understanding of the spectrum of cystic renal disease will allow the radiologist to make a more specific diagnosis and provide the clinician with optimal recommendations for further diagnostic testing and follow-up imaging.

Pathology, therapy and prognosis of papillary renal carcinoma

Papillary renal cell carcinoma (pRCC) accounts for approximately 10% of renal parenchymal tumors. There are two pRCC subtypes reported in several studies, but at present, there is limited molecular evidence to validate this pRCC subtyping in the daily routine. The utility of subtyping pRCC is based on reports describing that pRCC subtype is an independent predictor of outcome, with type 1 tumors showing significantly better survival than type 2 tumors. In this article, we summarize the relevant knowledge on pRCC regarding tumor features: clinical presentation, histopathology, electron microscopy, immunohistochemistry, cytogenetics, genetic/molecular and prognosis. We present an overview of the currently available pRCC treatment options and some of the new promising agents.

Case 221: Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome

History A 24-year-old woman presented to the emergency department with a history of acute urinary retention, gross hematuria, and left flank pain for 2 days. Past history was unrevealing. Her last menstrual period occurred 2 weeks prior to presentation. At physical examination, she had a temperature of 38.4°C. A palpable mass was noted in the suprapubic region, and a second mass was palpated in the left upper quadrant. Blood work revealed a hemoglobin level of 4.7 g/dL (normal range, 11.5-15.5 g/dL). Her coagulation profile and white blood cell count were within normal limits. Ultrasonography (US) of the abdomen and pelvis was performed and was followed by contrast material-enhanced (80 mL of iopamidol) computed tomography (CT) of the chest, abdomen, and pelvis. Magnetic resonance (MR) imaging of the abdomen and pelvis also was performed.

Common reduction of the Raf kinase inhibitory protein in clear cell renal cell carcinoma

Despite the recent progress in our understanding of clear cell renal cell carcinomas (ccRCCs), the etiology of ccRCC remains unclear. We reported here a prevailing reduction of the raf kinase inhibitory protein (RKIP) in ccRCC. In our examination of more than 600 ccRCC patients by western blot and immunohistochemistry, RKIP was significantly reduced in 80% of tumors. Inhibition of RKIP transcription in ccRCC occurs to greater levels than VHL transcription based on the quantification analysis of their transcripts in six large datasets of DNA microarray available in Oncomine™ with the median rank of suppression being 582 and 2343 for RKIP and VHL, respectively. Collectively, the magnitude of RKIP reduction and the levels of its downregulation match those of VHL. Furthermore, RKIP displays tumor suppressing activity in ccRCC. While modulation of RKIP expression did not affect the proliferation of A498 and 786-0 ccRCC cells and neither their ability to form xenograft tumors in NOD/SCID mice, ectopic expression or knockdown of RKIP inhibited or enhanced A498 and 786-0 ccRCC cell invasion, respectively. This was associated with robust changes in vimentin expression, a marker of EMT. Taken together, we demonstrate here that downregulation of RKIP occurs frequently at a rate that reaches that of VHL, suggesting RKIP being a critical tumor suppressor for ccRCC. This is consistent with RKIP being a tumor suppressor for other cancers.

Diagnostic approach to hereditary renal cell carcinoma

OBJECTIVE

The purpose of this article is to discuss the histopathologic features, genetics, clinical presentation, and imaging of hereditary renal cancer syndromes.

CONCLUSION

Hereditary renal cell carcinoma syndromes can be diagnosed with a pattern-based approach focused on the predominant histologic renal cell carcinoma subtype and associated renal and extrarenal features of each syndrome.

Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

Renal cell carcinoma (RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography (CT) is considered the examination of choice for the detection and staging of RCC. Multidetector CT (MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and three-dimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment.

Staging, surveillance, and evaluation of response to therapy in renal cell carcinoma: role of MDCT

Renal cell carcinoma is the most common malignant renal tumor in the adults. Significant advances have been made in the management of localized and advanced renal cell carcinoma. Surgery is the standard of care and accurate pre-operative staging based on imaging is critical in guiding appropriate patient management. Besides staging, imaging plays a key role in the post-operative surveillance and evaluation of response to systemic therapies. Both CT and MR are useful in the staging and follow up of renal cell carcinoma, but CT is more commonly used due to its lower costs and wider availability. In this article, we discuss and illustrate the role of multi-detector CT in pre-operative staging, post-operative surveillance, and evaluation of response to systemic therapy in renal cell carcinoma.

Birt-Hogg-Dubé syndrome in a patient presenting with familial spontaneous pneumothorax

Birt-Hogg-Dubé (BHD) syndrome is a recently discovered autosomal-dominant disease caused by a mutation in the folliculin gene. We report a patient with familial spontaneous pneumothorax who was found to have BHD syndrome. Patients with a personal and family history of pneumothoraces and computed tomographic (CT) findings of multiple pulmonary cysts should alert the thoracic surgeon to this syndrome; additional evaluation and testing may be warranted.

Role of percutaneous needle biopsy for renal masses

The role of percutaneous renal mass biopsy has expanded considerably in the past 10 years. The incidence of incidentally detected small (< 4 cm) solid renal masses is on the rise, and despite a commensurate increase in nephron-sparing treatment, the mortality rate from renal cell carcinoma remains the same. Earlier detection and treatment have not had dramatic effects on population outcome, implying that not all small renal masses will grow to be life-limiting. Indeed, many small solid renal masses are benign, and among those that are malignant, not all share the same malignant behavior. Percutaneous biopsy provides a minimally invasive method for discriminating benign from malignant renal masses, and portends the potential for stratifying malignant risk. With recent improvements in image-guided equipment and technique, percutaneous renal mass biopsy can be performed safely and effectively, with a low complication rate (< 5%) and a high diagnostic yield (> 90%).

Imaging management of incidentally detected small renal masses

Both imaging and intervention play an increasingly important role in the management of renal masses in general and renal cancer in particular. Indeed, radiologists are often the first to detect and diagnose renal cancer, and now with the burgeoning role of percutaneous ablation, they are often the treating physicians. Renal mass management begins with imaging, and although most can be diagnosed with a high degree of certainty using imaging, some remain indeterminate and require biopsy or observation, now referred to as active surveillance. Although active surveillance strategies have been employed for indeterminate renal masses that have a reasonable chance of being benign, recent data suggest that some renal cancers can undergo active surveillance safely. This article reviews the current imaging-based diagnostic evaluation of incidentally detected small renal masses, the burgeoning role of percutaneous biopsy, and how both imaging and biopsy are used to help select which patients need treatment and which can undergo active surveillance.