Translocation renal cell carcinoma: lack of negative impact due to lymph node spread

Outcome after treatment with axitinib in children, young adults, and adults with renal cell carcinoma: a narrative review

Renal cell carcinoma (RCC) is a very rare type of renal cancer in children and young adults. When metastasized or recurrent, no standards of care are available, and outcome is still poor. The tyrosine kinase inhibitor axitinib is approved for treatment of RCC in adults, but its effects in children and young adults with RCC remains unclear. Due to the histological and biological differences between children and adults, it is difficult to extrapolate knowledge on treatments from the adult to the pediatric and young adult setting. This paper summarizes the clinical characteristics and outcomes of patients with RCC who were treated with axitinib, with the aim to gain insight in the clinical efficacy of this compound in this young patient group.

The New WHO Category of "Molecularly Defined Renal Carcinomas": Clinical and Diagnostic Features and Management Implications

The evolution of classification of renal tumors has been impacted since the turn of the millennium by rapid progress in histopathology, immunohistochemistry, and molecular genetics. Together, these features have enabled firm recognition of specific, classic types of renal cell carcinomas, such as clear cell renal cell carcinoma, that in current practice trigger histologic-type specific management and treatment protocols. Now, the fifth Edition World Health Classification's new category of "Molecularly defined renal carcinomas" changes the paradigm, defining a total of seven entities based specifically on their fundamental molecular underpinnings. These tumors, which include TFE3-rearranged, TFEB-altered, ELOC-mutated, fumarate hydratase-deficient, succinate dehydrogenase-deficient, ALK-rearranged, and SMARCB1-deficient renal medullary carcinoma, encompass a wide clinical and histopathologic phenotypic spectrum of tumors. Already, important management aspects are apparent for several of these entities, while emerging therapeutic angles are coming into view. A brief, clinically-oriented introduction of the entities in this new category, focusing on relevant diagnostic, molecular, and management aspects, is the subject of this review.

A nomogram based on TFE3 IHC results and clinical factors as a preliminary screening scheme for TFE3-rearranged renal cell carcinoma

BACKGROUND

TFE3 immunohistochemistry (TFE3-IHC) is controversial in the diagnosis of TFE3-rearranged renal cell carcinoma (TFE3-rearranged RCC). This study is to investigate the accuracy and sensitivity of IHC and establish a predictive model to diagnose TFE3-rearranged RCC.

METHODS

Retrospective analysis was performed by collecting IHC and fluorescence in situ hybridization (FISH) results from 228 patients. IHC results were evaluated using three scoring systems. Scoring system 1 is graded based on nuclear staining intensity, scoring system 2 is graded based on the percentage of stained tumor cell nuclei, and scoring system 3 is graded based on both the nuclear staining intensity and the percentage. We collected patients' IHC results and clinical information. Important variables were screened based on univariate logistic regression analysis. Then, independent risk factors were established through multivariate logistic regression, and a nomogram model was constructed. The model was validated in internal test set and external validation set. The receiver operating characteristic curve (ROC curve), calibration curve, and decision curve analysis (DCA) were generated to assess discriminative ability of the model.

RESULTS

The accuracy of IHC based on three scoring systems were 0.829, 0.772, and 0.807, respectively. The model included four factors including age, gender, lymph node metastasis and IHC results. Area under the curve (AUC) values were 0.935 for the training set, 0.934 for the internal test set, 0.933 for all 228 patients, and 0.916 for the external validation set.

CONCLUSIONS

TFE3 IHC has high accuracy in the diagnosis of TFE3-rearranged RCC. Clinical information such as age and lymph node metastasis are independent risk factors, which can be used as a supplement to the results of TFE3 IHC. This study confirms the value of IHC in the diagnosis of TFE3-rearranged RCC. The accuracy of the diagnosis can be improved by incorporating IHC with other clinical risk factors.

Clinicopathologic Classification of Renal Cell Carcinoma in Patients ≤40 Years Old From Peru

INTRODUCTION

There are scant data on renal cell carcinoma (RCC) from relatively younger patients in South America using contemporary classification.

METHODS

Fifty-nine consecutively treated patients with RCC (≤40 years old) were assessed from the National Institute of Neoplastic Diseases in Peru from 2008 to 2020 (34 males; 25 females), age range of 13 to 40 years.

RESULTS

Most common presenting symptoms were flank pain (n = 40), hematuria (n = 19), and weight loss (n = 12). Associated conditions included 4 patients with proven or presumed tuberous sclerosis and 1 patient with von Hippel Lindau syndrome, all with clear cell RCC. Tumor histopathology was clear cell RCC in 32 of 59 (54%), chromophobe RCC in 6 of 59 (10%), and 5 of 59 (8%) each of papillary RCC and MiT family translocation-associated RCC. Four of 59 (7%) were FH-deficient RCC and 2 of 59 (3%) remained unclassified. The remaining tumors were isolated examples of clear cell papillary renal cell tumor, eosinophilic solid and cystic RCC (ESC RCC), RCC with fibromyomatous stroma, sarcomatoid RCC, and sarcomatoid clear cell RCC. Of the 4 FH-deficient RCCs, none had the classic morphology. The 5 MiT family translocation RCCs had variable morphology. There were 41 tumors without recurrence or metastases, 3 tumors with local recurrence only, 8 tumors with metastases only, and 7 tumors with both local recurrence and metastases.

CONCLUSIONS

The current study demonstrates the importance of special studies in accurately classifying RCC in younger individuals. The distribution of RCC subtypes in younger individuals is similar between 2 representative large institutions of the United States and Peru.

Targeted therapies in children with renal cell carcinoma (RCC): An International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG)-related retrospective descriptive study

INTRODUCTION

Introduction: Renal cell carcinoma (RCC) is a very rare pediatric renal tumor. Robust evidence to guide treatment is lacking and knowledge on targeted therapies and immunotherapy is mainly based on adult studies. Currently, the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) 2016 UMBRELLA protocol recommends sunitinib for metastatic or unresectable RCC.

METHODS

This retrospective study describes the effects of tyrosine kinase inhibitors (TKI), anti-programmed cell death 1 (PD-(L)1) monoclonal antibodies, and immunotherapeutic regimens in advanced-stage and relapsed pediatric RCC.

RESULTS

Of the 31 identified patients (0-18 years) with histologically proven RCC, 3/31 presented with TNM stage I/II, 8/31 with TNM stage III, and 20/31 with TNM stage IV at diagnosis. The majority were diagnosed with translocation type RCC (MiT-RCC) (21/31) and the remaining patients mainly presented with papillary or clear-cell RCC. Treatment in a neoadjuvant or adjuvant setting, or upon relapse or progression, included mono- or combination therapy with a large variety of drugs, illustrating center specific choices in most patients. Sunitinib was often administered as first choice and predominantly resulted in stable disease (53%). Other frequently used drugs included axitinib, cabozantinib, sorafenib, and nivolumab; however, no treatment seemed more promising than sunitinib. Overall, 15/31 patients died of disease, 12/31 are alive with active disease, and only four patients had a complete response. The sample size and heterogeneity of this cohort only allowed descriptive statistical analysis.

CONCLUSION

This study provides an overview of a unique series of clinical and treatment characteristics of pediatric patients with RCC treated with targeted therapies.

Factors associated with survival in paediatric and adolescent renal cell carcinoma: a population-based study

BACKGROUND

The purpose of this study was to conduct a population-based study to determine the prognosis of renal cell carcinoma (RCC) in children and adolescents.

METHODS

Patients with RCC who were registered in the Surveillance, Epidemiology, and End Results (SEER) program between 2000 and 2018 had their demographic and clinical characteristics evaluated retrospectively. The log-rank test was used to compare survival curves. Kaplan-Meier estimates were used to generate survival curves based on various factors. To identify factors associated with overall survival, Cox proportional-hazards regression was used.

RESULTS

A total of 251 patients were enrolled in the study. For all patients, the overall survival (OS) rates at 3- and 5- year were 93.5% and 92.0%, respectively. A multivariable study revealed that the following factors were independently associated with overall survival: sex, race, histologic type, SEER stage, AJCC stage, and type of surgery. Cox analysis showed that white patients had the lowest risk of mortality (hazard ratio (HR) 2.58, 95% confidence interval (CI), 1.33-4.99; P = 0.005), compared with black patients. Patients having metastatic disease had significantly higher mortality risk (HR 43, 95% CI, 14.8-125; P < 0.001) than the patients with localized tumour.

CONCLUSIONS

Our study emphasizes the importance of race, SEER stage, and surgery in the prognosis of paediatric RCC, providing valuable epidemiological evidence for clinical practice. Economic studies assessing a race/ethnic group specific strategy are also required.

Clear cell variant of pediatric renal cell carcinoma: Rare and challenging

We report a very rare case of clear cell variant of renal cell carcinoma (RCC) in a 3-year-old male child, who presented to us with a left-sided lump in his abdomen. Computed tomography (CT) scan and technetium-99 Dimercapto succinic acid (DMSA) scan revealed a large left renal mass with compromised left renal function. Left-sided nephroureterectomy was done and histopathology demonstrated clear cell carcinoma, possibly translocation-associated RCC (miT family) staged as pT2NxMx. Postoperative CT scans of the thorax and whole abdomen showed secondaries in the lungs and liver. We discussed treatment options in a multidisciplinary tumor board but meanwhile the child succumbed to respiratory failure.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

Estrogen associates with female predominance in Xp11.2 translocation renal cell carcinoma

Based on the epidemiological characteristics of susceptibility and age selectivity for women in Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC), we inferred that estrogen was to be blamed. Rad54 like 2 (Rad54l2) which might be one of key effector proteins of DNA damage mediated by estrogen was downregulated in numerous cancers, however, its role in epidemiological characteristics of Xp11.2 tRCC was needed to further study. We reviewed 1005 Xp11.2 tRCC cases and collected estrogen data and then compared the onset time of Xp11.2 tRCC cases in female with estrogen changing trend. An RNA-sequencing was performed in estrogen treated HK-2 cells and subsequently bioinformatic analysis was applied based on the Cancer Genome Atlas (TCGA) and GEO database. The male-to-female ratio of Xp11.2 tRCC was 1:1.4 and the median age of onset was 29.7 years old. The onset trend of female was similar to estrogen physiological rhythm (r = 0.67, p < 0.01). In Xp11.2 tRCC and HK-2 cells after estrogen treatment, Rad54l2 was downregulated, and GSEA showed that pathways significantly enriched in DNA damage repair and cancer related clusters after estrogen treated, as well as GO and KEGG analysis. Downregulation of Rad54l2 was in numerous cancers, including renal cell carcinoma (RCC), in which Rad54l2 expression was significantly decreased in male, age over 60 years old, T2&T3&T4 stages, pathologic SII&SIII&SIV stages as well as histologic G3&G4 grades, and cox regression analysis proved that Rad54l2 expression was a risk factor for overall survival, disease-specific survival and progression-free interval in univariate analysis. There existed female predominance in Xp11.2 tRCC and Rad54l2 might play vital role in estrogen mediating female predominance in Xp11.2 tRCC.

Clinical and pathological heterogeneity of four common fusion subtypes in Xp11.2 translocation renal cell carcinoma

Background

Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) is a group of rare and highly heterogeneous renal cell carcinoma (RCC). The translocation involving TFE3 and different fusion partners lead to overexpression of the chimeric protein. The purpose of this study is to explore the clinicopathological features of Xp11.2 tRCC with four common fusion subtypes.

Methods

We screened out 40 Xp11.2 tRCC patients from January 2007 to August 2021 in our institution. The diagnosis was initially confirmed by TFE3 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assay and their fusion partners were verified by RNA sequencing. Then the 40 cases were divided into two groups (DBHS family and non-DBHS family group) and a clinical comparison among the four common fusion subtypes was performed.

Results

Among the 40 cases, 11 cases with SFPQ-TFE3 gene fusion and 7 cases with NONO-TFE3 gene fusion were classified in DBHS group, the remaining cases with ASPL-TFE3 (11 cases) or PRCC-TFE3 (11 cases) gene fusion were classified in non-DBHS group. Lymph node (LN) metastasis (P=0.027) and distant metastasis (P=0.009) were more common seen in non-DBHS family group than DBHS family group and cases in DBHS family group have better progressive-free survival (PFS) (P=0.02). In addition, ASPL-TFE3 fusion was associated with worse outcome (P=0.03) while NONO-TFE3 fusion (P=0.04) predicted a better prognosis.

Conclusions

Different fusion partner genes may play a functional role in various morphology, molecular and biological features of Xp11.2 tRCCs. The impact of fusion partners on clinical characteristics of Xp11.2 tRCCs deserves further exploration.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

TFE3 Rearrangement and Expression in Renal Cell Carcinoma

TFE3 rearranged Renal cell carcinoma (RCC) is not very common, and demonstrates unique heterogenous morphological features overlapping other recognized entities and distinct immunoprofile. It can be seen in any age group, therefore practicing pathologists should be aware of the distinctive clinical settings and histologic findings associated with these tumors and subsequently employ an adequate panel of ancillary studies in order to confirm the diagnosis. Recognizing these entities remains crucial for future clinical trials and development of novel therapies.

Renal cell carcinoma in children and adolescents: A retrospective study of a French-Italian series of 93 cases

BACKGROUND

Renal cell carcinomas represent 2 to 5% of kidney malignancies in children and adolescents. Appropriate diagnostic and classification are crucial for the correct management of the patients and in order to avoid inappropriate preoperative chemotherapy, which is usually recommended if a Wilms tumor is suspected.

METHODS

a French-Italian series of 93 renal cell carcinomas collected from 1990 to 2019 in patients aged less than 18 years old was reclassified according to the 2016 WHO classification and the latest literature. TFE3 and TFEB FISH analyses and a panel of immunohistochemical stains were applied.

RESULTS

The median age at diagnosis was 11 years (range: 9 months - 17 years). MiT family (MiTF) translocation renal cell carcinomas accounted for 52% of the tumors, followed by papillary renal cell carcinomas (20%) and unclassified renal cell carcinomas (13%). Other subtypes, such as SDHB-deficient and Fumarate hydratase-deficient renal cell carcinomas, represented 1 to 3% of the cases. We also described a case of ALK-rearranged renal cell carcinoma with a metanephric adenoma-like morphology.

CONCLUSION

A precise histological diagnosis is mandatory as targeted therapy could be applied for some RCC subtypes, i.e., MiTF-translocation and ALK-translocation renal cell carcinomas. Moreover, some RCC subtypes may be associated with a predisposition syndrome that will impact patients' and family's management and genetic counseling. A precise RCC subtype is also mandatory for the clinical management of the patients and the inclusion in new prospective clinical trials.

Gene Expression Analysis of Aggressive Adult Xp11.2 Translocation Renal Cell Carcinoma at Clinical Stage T1N0M0 to Identify Potential Prognostic and Therapeutic Biomarkers

Xp11.2 translocation renal cell carcinoma (tRCC), involving transcription factor E3 (TFE3) gene fusions, is a rare and aggressive RCC variant when present in adults and has been recently recognized as a unique entity in RCC. Biomarkers and treatment guidelines do not exist for patients with aggressive Xp11.2 tRCC. The aim was to identify and evaluate therapeutic biomarkers for aggressive Xp11.2 tRCC. RNA sequencing was performed using formalin-fixed, paraffin-embedded tissues from 11 adult patients with clinical T1N0M0 Xp11.2 tRCC, including three patients with aggressive characteristics (recurrence or cancer-specific death after nephrectomy). Thirty genes were differentially expressed between the aggressive and non-aggressive groups, even after adjustment, and were associated with KEGG pathways related to the aggressiveness of Xp11.2 tRCC. PIK3R2, involved in various KEGG pathways, including the PI3K/AKT/mTOR pathway, was overexpressed in the Xp11.2 tRCC cell lines UOK120 and UOK146. The PI3K pathway inhibitor LY294002 showed a significant therapeutic benefit. This study provides the first candidate biomarker, PIK3R2, for aggressive clinical T1N0M0 Xp11.2 tRCC. Furthermore, this study is the first to recommend a targeted drug, LY294002, for aggressive Xp11.2 tRCC based on the molecular pathophysiology.

Investigation of temperature-responsive tocosomal nanocarriers as the efficient and robust drug delivery system for Sunitinib malate anti-cancer drug: Effects of MW and chain length of PNIPAAm on LCST and dissolution rate

In this study, for the first time, the coated tocosome by blend of chitosan, CS, and poly(N-isopropylacrylamide), PNIPAAm, was developed as the efficient and robust drug delivery system with improved drug encapsulation efficiency, extended stability, proper particle size and industrial upscaling for Sunitinib malate anti-cancer drug. Tocosome was synthesized by using Mozafari method as a scalable and robust method and without the need for organic solvents. The effects of tocosome composition and drug concentration on the stability, particle size of tocosome, zeta potential, encapsulation efficacy and loading of drug into it were investigated by Taguchi method, and optimum composition was selected for combining with the polymeric blend. Homopolymer of PNIPAAm was synthesized by two different polymerization methods, including free radical and reversible addition-fragmentation chain transfer (RAFT). Effects of molecular weight (MW) and chain length of the polymers on lower critical solution temperature (LCST) were examined. The developed nanocarrier in this research, CS-Raft-PNIPAAm-tocosome, indicated LCST value beyond 37°C (about 45°C) and this is suitable for hyperthermia and spatio-temporal release of drug particles.

Translocation carcinomas of the kidney

The MiT subfamily of transcription factors includes TFE3, TFEB, TFEC, and MITF. Gene fusions involving two of these transcription factors have been well-characterized in renal cell carcinoma (RCC). The TFE3-rearranged RCC (also known as Xp11 translocation RCC) was first officially recognized in the 2004 World Health Organization (WHO) renal tumor classification. The TFEB-rearranged RCC, which typically harbor a t(6;11)(p21;q12) translocation which results in a MALAT1-TFEB gene fusion, were first officially recognized in the 2016 WHO renal tumor classification. These two subtypes of translocation RCC have many similarities. Both disproportionately involve young patients, although adult translocation RCC overall outnumber pediatric cases. Both often have unusual and distinctive morphologies; the TFE3-rearranged RCCs frequently have clear cells with papillary architecture and abundant psammoma bodies, while the TFEB-rearranged RCCs frequently have a biphasic appearance with both small and large epithelioid cells and nodules of basement membrane material. However, the morphology of these two neoplasms can overlap, with one mimicking the other or other more common renal neoplasms. Both of these RCC underexpress epithelial immunohistochemical markers, such as cytokeratin and epithelial membrane antigen, relative to most other RCC. Unlike other RCC, both frequently express the cysteine protease cathepsin k and often express melanocytic markers like HMB45 and Melan A. Finally, TFE3 and TFEB have overlapping functional activity as these two transcription factors frequently heterodimerize and bind to the same targets. Therefore, these two neoplasms are now grouped together under the heading of "MiT family translocation RCC." Approximately 50 renal cell carcinomas with gene fusions involving the anaplastic lymphoma kinase (ALK) gene have now been reported. While those with a Vinculin-ALK fusion have distinctive features (predilection to affect children with sickle cell trait and to show solid architecture with striking cytoplasmic vacuolization), other ALK-fusion RCCs have more varied clinical presentations and pathologic features. This review summarizes our current knowledge of these recently described RCC.

Key Renal Neoplasms With a Female Predominance

Renal neoplasms largely favor male patients; however, there is a growing list of tumors that are more frequently diagnosed in females. These tumors include metanephric adenoma, mixed epithelial and stromal tumor, juxtaglomerular cell tumor, mucinous tubular and spindle cell carcinoma, Xp11.2 (TFE3) translocation-associated renal cell carcinoma, and tuberous sclerosis complex (somatic or germline) associated renal neoplasms. The latter category is a heterogenous group with entities still being delineated. Eosinophilic solid and cystic renal cell carcinoma is the best-described entity, whereas, eosinophilic vacuolated tumor is a proposed entity, and the remaining tumors are currently grouped together under the umbrella of tuberous sclerosis complex/mammalian target of rapamycin-related renal neoplasms. The entities described in this review are often diagnostic considerations when evaluating renal mass tissue on biopsy or resection. For example, Xp11.2 translocation renal cell carcinoma is in the differential when a tumor has clear cell cytology and papillary architecture and occurs in a young or middle-aged patient. In contrast, tuberous sclerosis complex-related neoplasms often enter the differential for tumors with eosinophilic cytology. This review provides an overview of the clinical, gross, microscopic, immunohistochemical, genetic, and molecular alterations in key renal neoplasms occurring more commonly in females; differential diagnoses are also discussed regardless of sex predilection.

New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia

The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.

The Molecular Characteristics of Non-Clear Cell Renal Cell Carcinoma: What's the Story Morning Glory?

Non-clear cell renal cell carcinomas are a miscellaneous group of tumors that include different histological subtypes, each one characterized by peculiarity in terms of genetic alteration, clinical behavior, prognosis, and treatment response. Because of their low incidence and poor enrollment in clinical trials, alongside their heterogeneity, additional efforts are required to better unveil the pathogenetic mechanisms and, consequently, to improve the treatment algorithm. Nowadays, tyrosine kinase inhibitors, mTOR and MET inhibitors, and even cisplatin-based chemotherapy and immunotherapy are potential weapons that are still under evaluation in this setting. Various biomarkers have been evaluated for detecting progression and monitoring renal cell carcinoma, but more studies are necessary to improve this field. In this review, we provide an overview on the molecular characteristics of this group of tumors and the recently published trials, giving an insight into what might become the future therapeutic standard in this complex world of non-clear cell kidney cancers.

Characteristics and outcome of pediatric renal cell carcinoma patients registered in the International Society of Pediatric Oncology (SIOP) 93-01, 2001 and UK-IMPORT database: A report of the SIOP-Renal Tumor Study Group

In children, renal cell carcinoma (RCC) is rare. This study is the first report of pediatric patients with RCC registered by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Pediatric patients with histologically confirmed RCC, registered in SIOP 93-01, 2001 and UK-IMPORT databases, were included. Event-free survival (EFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Between 1993 and 2019, 122 pediatric patients with RCC were registered. Available detailed data (n = 111) revealed 56 localized, 30 regionally advanced, 25 metastatic and no bilateral cases. Histological classification according to World Health Organization 2004, including immunohistochemical and molecular testing for transcription factor E3 (TFE3) and/or EB (TFEB) translocation, was available for 65/122 patients. In this group, the most common histological subtypes were translocation type RCC (MiT-RCC) (36/64, 56.3%), papillary type (19/64, 29.7%) and clear cell type (4/64, 6.3%). One histological subtype was not reported. In the remaining 57 patients, translocation testing could not be performed, or TFE-cytogenetics and/or immunohistochemistry results were missing. In this group, the most common RCC histological subtypes were papillary type (21/47, 44.7%) and clear cell type (11/47, 23.4%). Ten histological subtypes were not reported. Estimated 5-year (5y) EFS and 5y OS of the total group was 70.5% (95% CI = 61.7%-80.6%) and 84.5% (95% CI = 77.5%-92.2%), respectively. Estimated 5y OS for localized, regionally advanced, and metastatic disease was 96.8%, 92.3%, and 45.6%, respectively. In conclusion, the registered pediatric patients with RCC showed a reasonable outcome. Survival was substantially lower for patients with metastatic disease. This descriptive study stresses the importance of full, prospective registration including TFE-testing.

A new risk-scoring system to predict Xp11.2 translocation renal cell carcinoma in adults

Objective

The objective was to derive and validate a practical scoring system for preoperative diagnosis of Xp11.2 translocation renal cell carcinoma (RCC) in adults.

Methods

Epidemiology, symptomatology, and imaging methods were correlated between patients with common RCC and those with Xp11.2 translocation RCC using a derivation study (N = 6352) and a validation study (N = 127). Univariate analysis of risk factors was performed to derive a scoring system to predict the occurrence of Xp11.2 translocation RCC in adults. The Hosmer–Lemeshow goodness-of-fit test and receiver operating characteristic (ROC) curve were used to validate the scoring system.

Results

Based on odd ratios, three low-risk factors (sex, gross haematuria, and intratumoural calcification) and three high-risk factors (age, unenhanced computed tomography density, and enhancement pattern) were given weighted scores of 1 and 2, respectively. Patients who scored 3 to 5 points underwent an additional magnetic resonance imaging examination. The final scoring system had a sensitivity of 81.0% and a specificity of 98.0%.

Conclusion

We established a practical scoring system for the preoperative diagnosis of Xp11.2 translocation RCC in adults, which can be optimised through further clinical findings in the future.

An Intratumoral Aneurysm and an Extrarenal Synchronous Cystic Tumour in a Case of a Renal Cell Carcinoma

Background

Renal cell carcinoma is a heterogeneous group of malignant tumors originating from the kidney. We report a case of a renal cell carcinoma with two very rare associates, i.e., a large intratumoral aneurysm and a synchronous extrarenal cystic tumor outside the main tumor. Case Presentation. A 31-year-old woman, who presented with painless hematuria and loin pain, was diagnosed to have a large renal mass measuring 15 × 9 × 8.5 cm with an intralesional arterial aneurysm measuring 4.5 × 3.5 cm on radiological examination. During surgery, a separate cystic tumor measuring 5 × 4.5 × 4 cm with distinct vascular supply was noted anteromedial to the kidney, in addition to the renal mass. The histology of the main tumor was compatible with t(6:11) type microphthalmia-associated transcription factor (MiT) family translocation RCC. The aneurysm was of venous origin histologically, and a radiologically demonstrable arteriovenous fistula was recognized retrospectively. The extrarenal cyst has also showed similar histology to that of main tumor and had no evidence of a degenerated lymph node. Discussion. Although few cases were reported with various vascular anomalies associated with a renal tumor, this is the first ever case to find an arteriovenous fistula with a secondary venous aneurysm located inside a malignant renal mass. Similarly, no solid RCC is reported to present with an extrarenal malignant cystic nodule. The prognostic and oncological significance of the extrarenal malignant cyst is unclear. Both of these extraordinary features of this case were not properly identified on preoperative imaging. Reviewing the preoperative imaging when pathology reports are available helps to overcome difficulties in making the final diagnosis of complex cases.

Conclusion

RCCs can house vascular anomalies like arteriovenous fistula and venous aneurysms and can exist with concomitant extrarenal malignant cystic nodules.

Management of colon-invading renal cell carcinoma: Operative technique and systematic review

Invasion into adjacent organs by non-metastatic renal cell carcinoma (RCC) occurs in 1% of patients suitable for resection. Colonic invasion is rare and presents technical challenges. No prospective data exists to guide management of these patients. We present the first reported case of a colon-invading RCC managed with simultaneous open right radical nephrectomy and extended right hemicolectomy. PubMed, Scopus and EMBASE databases were searched for relevant case reports reporting management of colon-invading renal cell carcinoma. Case reports, case series and cohort studies were eligible. A chart review was performed on a patient who presented with right-sided colon-invading RCC. Four previously reported cases were identified. The current case was managed with simultaneous open radical nephrectomy and extended right hemicolectomy. The patient remains well six months postoperatively with no evidence of disease recurrence. Histopathological evaluation of the resected specimen confirmed a T4 clear cell RCC with sarcomatoid differentiation. Colon-invading RCC is rare. This is the first reported case of right-sided, colon-invading RCC treated with radical resection. The current case confirms radical resection is a feasible management strategy for similar presentations. En bloc resection of involved organs remains the only potentially curative option for locally advanced disease.

Renal cell carcinoma in children and adolescents: Single-center experience and literature review

Renal cell carcinoma (RCC) is infrequent in the pediatric population. In addition, till date, only a few reports have summarized the characteristics of pediatric RCC and differences between pediatric and adult RCC. Therefore, the current study aimed to investigate the clinical characteristics of RCC in children and adolescents, and identify the differences between children and adolescent patients and adult patients through literature retrieval.The data of 13 pediatric patients diagnosed with RCC at the Children's Hospital of Zhejiang University School of Medicine between 2005 and 2019 were retrospectively analyzed.Three patients were aged <5 years, 2 were aged 6 to 10 years, and 8 were aged 11 to 18 years. Among the 13 patients, common clinical manifestations included abdominal pain in 5 patients, gross hematuria in 4, and an abdominal mass in 1, while the other 3 patients were incidentally detected after an abdominal contusion. The pathological types were microphthalmia family translocation RCC in 9 patients, clear-cell RCC in 2, papillary RCC in 1, and unclassified in 1. All the children underwent radical nephrectomy, including 2 patients with advanced disease who underwent preoperative transcatheter arterial chemoembolization. The mean follow-up time was 58.6 months. Two patients died after 4 and 17 months of follow-up, respectively.In conclusion, microphthalmia family translocation renal cell carcinoma is the predominant type of pediatric RCC associated with advanced tumor stage. The early diagnosis and treatment of pediatric patients is important for improving prognosis. Nevertheless, future studies are urgently needed to determine the treatment for pediatric advanced RCC to increase the survival rate.

Metastatic adult Xp11.2 translocation renal cell carcinoma with TFE3 gene fusion in complete remission

Xp11 translocation renal cell carcinoma (RCC) accounts for most pediatric cases of RCC but is uncommon in adults. It has an aggressive course in adults with poor response to chemoradiation. We describe a 64-year-old man with Xp11 translocation RCC who achieved complete remission following surgery and chemoimmunotherapy.

Are tumor-associated micro-angiogenesis and lymphangiogenesis considered as the novel prognostic factors for patients with Xp11.2 translocation renal cell carcinoma?

Background

Tumor micro-angiogenesis and lymphangiogenesis are effective prognostic predictors in many solid malignancies. However, its role on Xp11.2 translocation RCC has not been fully elucidated. Herein, we purposed to explore the correlation between quantitative parameters of tumor-related micro-angiogenesis or lymphangiogenesis and the prognosis of Xp11.2 translocation renal cell carcinoma (Xp11.2 translocation RCC).

Methods

Tissue samples were obtained from 34 Xp11.2 translocation RCC and 77 clear cell renal cell carcinoma (ccRCC) between January 2007 and December 2018. Micro-angiogenesis was detected using CD34 antibody and quantified with microvessel density (MVD) and microvessel area (MVA), while the lymphangiogenesis in RCC was immunostained with D2–40 antibody and assessed using lymphatic vessel density (LVD) and lymphatic vessel area (LVA). The Kaplan-Meier method of survival analysis was used to estimate prognosis, and both univariate and multivariate analysis was performing using the Cox proportional hazards.

Results

The MVD and MVA of Xp11.2 translocation RCC in two detected areas (intratumoral and peritumoral area) were not significantly different from that of ccRCC (all P > 0.05). Notably, D2–40-positive lymphatic vessels of Xp11.2 translocation RCC were highly detected in the peritumoral area compared to the intratumoral area. Interestingly, the peritumoral LVD and LVA of Xp11.2 translocation RCC were higher than that of ccRCC (all P < 0.05). Furthermore, both intratumoral MVD or MVA and peritumoral LVD or LVA were significantly associated with pT stage, pN stage, cM stage, AJCC stage, and WHO/ISUP grade (all P < 0.05). Univariate analysis of Cancer-specific survival (CSS) revealed that CSS was substantially longer in patients with low intratumoral MVD or MVA than in patients with high intratumoral MVD or MVA (P = 0.005 and P = 0.001, respectively). Lastly, the Cox proportional hazards model in CSS demonstrated that both intratumoral MVD or MVA and peritumoral LVD or LVA were not independent prognostic parameters (all P > 0.05).

Conclusions

This study outlines that Xp11.2 translocation RCC is a highly vascularized solid RCC, characterized by rich lymph vessels in the peritumoral area. Quantitative parameters of micro-angiogenesis and lymphangiogenesis could not be considered as novel prognostic factors for patients with xp11.2 translocation RCC.

Pediatric and young adult renal cell carcinoma

Renal cell carcinoma (RCC) is rare in children but is the most common renal tumor in adults. Pediatric RCC has different clinical characteristics, histopathology, and treatment compared with adult disease. Databases were reviewed from inception to February 2020, identifying 32 publications pertaining to 350 patients under 27 years. Surgery is the cornerstone for cure in localized RCC. Lymph node dissection remains controversial. Conventional radiotherapy has no curative role in RCC; similarly, conventional chemotherapy has not proven to be effective in large cohorts. Pediatric metastatic RCC has a poor outlook. There are no published prospective studies demonstrating which adjuvant therapy could improve outcome. Sunitinib, a tyrosine kinase inhibitor, is recommended in this group despite limited evidence. This review provides an overview for pediatric RCC, including the evolving role of precision medicine.

A prospective study of pediatric and adolescent renal cell carcinoma: A report from the Children's Oncology Group AREN0321 study

BACKGROUND

To the authors' knowledge, AREN0321 is the first prospective clinical study of pediatric and adolescent renal cell carcinoma (RCC). Goals of the study included establishing epidemiological, treatment, and outcome data and confirming that patients with completely resected pediatric RCC, including lymph node-positive disease (N1), have a favorable prognosis without adjuvant therapy.

METHODS

From 2006 to 2012, patients aged <30 years with centrally reviewed pathology of RCC were enrolled prospectively.

RESULTS

A total of 68 patients were enrolled (39 of whom were male; median age of 13 years [range, 0.17-22.1 years]). Stage was classified according to the American Joint Committee on Cancer TNM stage seventh edition as stage I in 26 patients, stage II in 7 patients, stage III in 26 patients, and stage IV in 8 patients, and was not available in 1 patient. Sixty patients underwent resection of all known sites of disease, including 2 patients with stage IV disease. Surgery included radical nephrectomy (53 patients [81.5%]), partial nephrectomy (12 patients [18.5%]), and unknown (3 patients [4.4%]). Histology was TFE-associated RCC (translocation-type RCC; tRCC) in 40 patients, RCC not otherwise specified and/or other in 13 patients, papillary RCC in 9 patients, and renal medullary carcinoma (RMC) in 6 patients. Lymph node status was N0 in 21 patients, N1 in 21 patients (tRCC in 15 patients, RMC in 3 patients, papillary RCC in 2 patients, and not otherwise specified and/or other in 1 patient), and Nx in 26 patients. The 4-year event-free survival and overall survival rates were 80.2% (95% CI, 69.6%-90.9%) and 84.8% (95% CI, 75.2%-94.5%), respectively, overall and 87.5% (95% CI, 68.3%-100%) and 87.1% (95% CI, 67.6%-100%), respectively, for the 16 patients with N1M0 disease. Among patients presenting with metastases, 2 of 8 patients (2 of 5 patients with RMC) were alive (1 with disease) at the time of last follow-up, including 1 patient who was lost to follow-up (succinate dehydrogenase deficiency). The predominant RCC subtypes associated with mortality were tRCC and RMC.

CONCLUSIONS

Favorable short-term outcomes can be achieved without adjuvant therapy in children and adolescents with completely resected RCC, independent of lymph node status. A prospective study of patients with tRCC and RMC with M1 or recurrent disease is needed to optimize treatment.

Comprehensive Genomic Analysis of Translocation Renal Cell Carcinoma Reveals Copy-Number Variations as Drivers of Disease Progression

PURPOSE

Translocation renal cell carcinoma (tRCC) is a rare, aggressive renal cell carcinoma (RCC) subtype. There is currently limited understanding on the role of molecular alterations in the pathogenesis and progression of these tumors. We investigated the association between somatic alterations and clinical outcomes in two independent cohorts profiled using DNA sequencing.

EXPERIMENTAL DESIGN

Twenty-two tRCCs underwent targeted sequencing [Memorial Sloan Kettering Cancer Center (MSK)-IMPACT]; a subset was profiled using exome-sequencing and combined with exome data from The Cancer Genome Atlas (TCGA) for analysis. The prognostic value of specific somatic aberrations, tumor mutation burden (TMB), and fraction of copy-number-altered genome (FCNAg) was explored. In TCGA cases, neoantigen prediction and immune cell deconvolution were performed using RNA-sequencing and exome data. Overall survival estimates were computed using the Kaplan-Meier method; time-on-treatment was calculated for 14 MSK-IMPACT patients who underwent systemic therapy. Associations between molecular features and outcomes were evaluated using nonparametric testing.

RESULTS

Copy-number aberrant tRCCs were associated with poor overall survival (P = 0.03). Pediatric patients had tumors with lower FCNAg (P = 0.01). In one adult case with two chronologically distinct tumor samples sequenced, we confirmed that copy-number events occurred early during evolution. TERT promoter mutations were found exclusively in high-stage tumors. We found that tRCCs displayed distinct angiogenesis and PD-L1 gene expression profiles compared with other RCC subtypes.

CONCLUSIONS

Tumors molecularly defined by increased copy-number variations were associated with aggressive disease in tRCC. A higher burden of genomic events in adults compared with pediatric cases likely reflects a more aggressive clinical course. The unique immunophenotypic characteristics of tRCC merit further exploration.

Characteristics and Outcome of Children with Renal Cell Carcinoma: A Narrative Review

Pediatric renal cell carcinoma (RCC) is a rare type of kidney cancer, most commonly occurring in teenagers and young adolescents. Few relatively large series of pediatric RCC have been reported. Knowledge of clinical characteristics, outcome and treatment strategies are often based on the more frequently occurring adult types of RCC. However, published pediatric data suggest that clinical, molecular and histological characteristics of pediatric RCC differ from adult RCC. This paper summarizes reported series consisting of ≥10 RCC pediatric patients in order to create an up-to-date overview of the clinical and histopathological characteristics, treatment and outcome of pediatric RCC patients.

[MiT family translocation renal cell carcinomas: Natural history, molecular features and multidisciplinary management]

MiT family translocation renal cell carcinomas (tRCC) represent a rare subtype of renal cell carcinomas. These tumors have been introduced for the first time in the World Health Classification (WHO) classification of kidney cancers in 2004. tRCC are characterized by reccurent translocations involving members of the MiT family transcription factors, mainly TFE3 and TFEB. The estimated incidence of these tumors is ∼1-5 % among all renal cell carcinomas, with female prodominance. tRCC were initially described in children, and the spectrum has been expanded over time to encompass adolescents and adults. TFE3- and TFEB-rearranged RCC harbor characteristic clinicopathological and immunohistochemical features and fluorescent hybridization in situ is considered the gold standard for their diagnosis, although it has some limitations especially when the partners are located in the vicinity of TFE3. Nephron-sparing surgery is an efficient treatment of localized cases when achievable. In metastatic setting, targeted agents and immunotherapy showed modest efficacy, with response rates and median overall survival inferior to those observed in clear-cell renal cell carcinomas. Management of tRCC necessite a multidisciplinary team and accrual in clinical trials have to be encouraged when possible. Novel biological insights are urgently awaited to better understand the mechanisms associated with kidney oncogenesis in this setting, and ultimately help to identify therapeutic targets.

Comparative Clinicopathologic Characteristics and Outcomes of Paediatric and Adult Xp11 Translocation Renal Cell Carcinomas: a Retrospective Multicentre Study in China

This study aimed to compare the clinicopathologic features and prognosis in patients with Xp11 translocation renal cell carcinomas (RCCs). In total, 8083 RCCs were screened at five centres from January 2007 to December 2018, including 8001 adults (≥18 years) and 82 children (<18 years). Finally, 73 adults and 17 children were identified as Xp11 translocation RCCs, accounting for 1.1% (90 of 8083) of the RCCs. However, 4 children and 1 adult were excluded because of loss to follow-up when performing the survival analysis. The proportion of paediatric and adult Xp11 translocation RCCs was 20.7% (17 of 82) and 0.9% (73 of 8001) of RCCs, respectively, and the incidence in children and adults was significantly different (P < 0.01). Lymph node positivity (LN+) most commonly occurred in children (58.8%) compared with adults (28.8%; P = 0.02), but children with LN+ showed significantly higher five-year overall survival and progression-free rates (OS: 75.0%; PFS: 64.8%) than adult patients (OS: 40.3%; PFS: 0%) (log-rank P^PFS < 0.01; P^OS = 0.04). Multivariable analysis indicated that local lymph node metastasis was associated with both PFS (HR = 0.10; 95% CI 0.02–0.51; P = 0.01) and OS (HR = 0.11; 95% CI 0.01–0.98; P = 0.04) in adults. Adult patients with LN+ may indicate a worse prognosis than paediatric patients.

MiT family translocation renal cell carcinomas: A 15th anniversary update

Microphthalmia (MiT) family translocation renal cell carcinomas (RCCs) are a heterogeneous category of renal tumors which all express MiT transcription factors, typically from chromosomal translocation and rarely from gene amplification. This tumor family has two major subtypes [i.e., Xp11 translocation RCC and t(6;11) RCC] and several related neoplasms (i.e., TFEB amplification RCC and melanotic Xp11 translocation renal cancers). Increased understanding of the clinical, pathological, molecular and prognostic heterogeneity of these tumors, since their official recognition in 2004, provides the opportunity to identify prognostic biomarkers and to understand the reasons for tumor aggression. We will review the literature from the past 15 years and highlight the need for a greater understanding of the molecular mechanisms underpinning heterogeneous tumor behavior.

Treatment of advanced pediatric renal cell carcinoma

BACKGROUND

Pediatric renal cell carcinoma (pRCC) is the second most common renal malignancy of childhood; however, treatment data for advanced disease is lacking.

METHODS

A retrospective analysis of pRCC patients (age < 21 years at diagnosis) treated between 2000 and 2015 at Cincinnati Children's Hospital Medical Center was undertaken, with specific focus on medical therapies, accompanied by a detailed literature review.

RESULTS

Twenty-four patients (median age = 15 years) were identified; 11 were female. Past history of kidney pathology (4) and prior hematologic/oncologic diagnoses (5) were common associated findings. Translocation morphology RCC (tRCC) was the most common subtype (16; 64%), followed by papillary (6; 24%), clear cell renal cell carcinoma (ccRCC) (1), and chromophobe (1). The TNM stage distribution was I (8; 33%), II (2; 8%), III (3; 13%), and IV (11; 46%). Eleven patients with stage IV disease all had tRCC and received medicinal anticancer therapies, the most common being antiangiogenic (10), conventional chemotherapy (8), mTOR inhibition (7), and immunotherapy (3). Four patients also received small-port radiotherapy. The mean time to progression (TTP) was longest for axitinib (n = 2; TTP = 7.8 m; range 5.5-10 m) and sunitinib (n = 6; TTP = 4.7 m; range 0.3-12 m). Overall, 20 cases of pediatric RCC who received RCC-directed medicinal therapy with outcome data have been previously reported.

CONCLUSIONS

For patients with unresectable pRCC requiring systemic therapy, available data are scarce. Data herein support an increased TTP with antiangiogenic therapy in tRCC supporting a formal study of antiangiogenic therapies through multicooperative-group collaboration.

Microphthalmia family of transcription factors associated renal cell carcinoma

The microphthalmia (MiT) subfamily of transcription factors includes TFE3, TFEB, TFEC, and MITF. In the 2016 World Health Organization classification, MiT family translocation renal cell carcinoma (tRCC) including Xp11 tRCC and t(6;11) RCC, was newly defined as an RCC subtype. Xp11 and t(6;11) RCC are characterized by the rearrangement of the MiT transcription factors TFE3 and TFEB, respectively. Recent studies identified the fusion partner-dependent clinicopathological and immunohistochemical features in TFE3-rearranged RCC. Furthermore, RCC with TFEB amplification, melanotic MiT family translocation neoplasms, was identified may as a unique subtype of MiT family associated renal neoplasms, along with MITF associated RCC. In this review, we will collect available literature of these newly-described RCCs, analyze their clinicopathological and immunohistochemical features, and summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of these rare subtypes of RCCs, and eventually promote clinical management strategies.

Genetic Predisposition to Renal Cell Carcinoma: Implications for Counseling, Testing, Screening, and Management

In many individuals with renal cell carcinoma (RCC), a hereditary cause may have contributed to cancer development. Various risk factors can be suggestive of a genetic contribution, including early disease onset, multifocal or bilateral tumors, family history of RCC, and personal/family history of other benign or malignant tumors. Genetic counseling and understanding of the entire family tree are the first steps in evaluation and will determine if the patient should proceed with testing. Methods of testing have changed to next-generation sequencing, which allows multiple genes to be evaluated together. The results of testing have significant implications for the individual and his or her family members. Screening of the kidney and at-risk organs ensues, with most algorithms focused on early diagnosis and intervention to limit morbidity and mortality of disease manifestations. A comprehensive clinical program that can offer multidisciplinary care is useful for several complex cancer syndromes. Management of localized and advanced hereditary kidney cancers may differ from the sporadic forms of RCC. Knowledge of the genetics can have significant management implications and if necessary genetic evaluation can be expedited to allow treatment decisions.

t(6;11) renal cell carcinoma: a study of seven cases including two with aggressive behavior, and utility of CD68 (PG-M1) in the differential diagnosis with pure epithelioid PEComa/epithelioid angiomyolipoma

Renal cell carcinomas with t(6;11) chromosome translocation involving the TFEB gene are indolent neoplasms which often occur in young patients. In this study, we report seven cases of renal cell carcinoma with TFEB rearrangement, two of whom had histologically proven metastasis. Patients (4F, 3M) ranged in age from 19 to 55 years (mean 37). One patient developed paratracheal and pleural metastases 24 months after surgery and died of disease after 46 months; another one recurred with neoplastic nodules in the perinephric fat and pelvic soft tissue. Histologically, either cytological or architectural appearance was peculiar in each case whereas one tumor displayed the typical biphasic morphology. By immunohistochemistry, all tumors labelled for cathepsin K, Melan-A and CD68 (KP1 clone). HMB45 and PAX8 staining were detected in six of seven tumors. All tumors were negative for CD68 (PG-M1 clone), CKAE1-AE3, CK7, CAIX, and AMACR. Seven pure epithelioid PEComa/epithelioid angiomyolipomas, used as control, were positive for cathepsin K, melanocytic markers, and CD68 (PG-M1 and KP1) and negative for PAX8. Fluorescence in situ hybridization results showed the presence of TFEB gene translocation in all t(6;11) renal cell carcinomas with a high frequency of split TFEB fluorescent signals (mean 74%). In the primary and metastatic samples of the two aggressive tumors, increased gene copy number was observed (3-5 fluorescent signals per neoplastic nuclei) with a concomitant increased number of CEP6. Review of the literature revealed older age and larger tumor size as correlating with aggressive behavior in these neoplasms. In conclusion, we present the clinical, morphological and molecular features of seven t(6;11) renal cell carcinomas, two with histologically demonstrated metastasis. We report the high frequency of split signals by FISH in tumors with t(6;11) chromosomal rearrangement and the occurrence of TFEB gene copy number gains in the aggressive cases, analyzing either the primary or metastatic tumor. Finally, we demonstrate the usefulness of CD68 (PG-M1) immunohistochemical staining in distinguishing t(6;11) renal cell carcinoma from pure epithelioid PEComa/epithelioid angiomyolipoma.

Synchronous Presentation of Renal Cell Carcinoma and Hodgkin Lymphoma in an Adolescent

BACKGROUND

Coincidence of renal cell carcinoma (RCC) and hematologic malignancies has been reported in adults but not in children.

OBSERVATION

We report a case of a 16-year-old girl in whom RCC was incidentally discovered on the computed tomography scan that was performed to stage her underlying Hodgkin lymphoma. Analysis of constitutional cytogenetics for common genetic aberrations that predispose to RCC did not reveal any mutations or genetic variations. However, cytogenetics on the RCC tumor demonstrated a rare reciprocal translocation between chromosomes 6 and 11, t(6;11)(p21;q12). After undergoing partial nephrectomy with regional lymphadenectomy and treatment with multiagent chemotherapy, patient is cancer-free, now 33 months from end of therapy.

CONCLUSIONS

This case highlights the importance for histologic confirmation of a renal mass when concurrently discovered during the diagnostic evaluation of other malignancies.

First Report of Renal Cell Carcinoma Metastasizing to the Clivus in a Pediatric Patient

BACKGROUND

The clivus is a rare site of tumor occurrence in general, and metastases to this site are especially rare. Renal cell carcinoma is an uncommon entity in the pediatric population. Although not infrequent in adults, when it does occur, metastases to the clivus are extremely uncommon, only having been reported 3 times in the literature. All of these cases involved adults in their sixth decade.

CASE DESCRIPTION

We present the first report in the literature of renal cell carcinoma occurring in a pediatric patient and spreading to the clivus. This 11-year-old girl presented with headaches and diplopia based on a left-sided sixth cranial nerve palsy, in the context of a wasting disease. She was also found to have vague abdominal fullness, although it was only after biopsy of a clivus lesion identified on brain scanning that its true nature became apparent, prompting abdominal scans, which revealed a renal mass with hepatic metastases.

CONCLUSIONS

This article reports for the first time in the literature the spread of a translocation renal cell carcinoma to the clivus in a young child. This serves to alert practitioners to this possibility when faced with a similar scenario.

Nephron-sparing surgery in the treatment of pediatric renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions

PURPOSE

To investigate the safety and efficacy of nephron-sparing surgery (NSS) in the treatment of pediatric Xp11.2 translocation renal cell carcinoma (RCC).

METHODS

Clinical characteristics of 9 RCC children (7 males and 2 females) with Xp11.2 translocation who received NSS between January 1973 and December 2015 were retrospectively analyzed. The mean age was 7.8years (range: 4.5-13.5years). Xp11.2 translocation RCC was found in the left side in 4 patients and right in 5. 3 tumors were located in the upper pole of the kidney, 1 in the middle dorsal, 1 in the middle ventral and 4 in the lower pole. RCC presented with painless gross hematuria in 4 patients, abdominal mass in 1, and as an incidental finding by ultrasound examination in 4 patients. The mean course of hematuria was 3months (range: 1-7months). The mean tumor diameters were 3.7cm (range: 2.2-6.9cm).

RESULTS

All the patients received NSS with open transperitoneal approach. The mean operative time and estimated blood loss were 115min and 40ml, respectively. The time of renal pedicle clamping was 19-25min (mean: 21.5min). No complications (such as leakage of urine, prolonged drainage or secondary bleeding) were noted. No patients experienced local recurrence during the mean of 50.1-month follow-up (range: 13-117months). Intravenous urography (IVU) or contrast-enhanced CT was conducted at 6months after surgery which showed favorable kidney function in all patients.

CONCLUSION

Xp11.2 translocation RCC is a predominant pathological but biologically inert type of pediatric RCC. For Xp11.2 translocation RCC sized <4-7cm in diameter and located in one pole, NSS is safe and feasible.

TYPE OF STUDY

Treatment Studies, LEVEL IV.

Postoperative recurrence of adult renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion

Objective

To analyze the postoperative recurrence of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 tRCC).

Methods

This retrospective study was approved by the institutional review board and performed in accordance with the ethical standards established by the institution. Demographic, clinical, pathological, and follow-up data were compiled for the study cohort.

Results

During a mean follow-up of 41.3 months (range, 3–104 months), 8 of 34 patients with Xp11.2 tRCC were confirmed to have recurrence. Three of these patients died with poor outcomes due to a vena cava tumor embolus, and one died of distant metastasis 48 months after the initial nephrectomy during which lymph node metastasis was found. Three patients survived after cytoreduction surgery. One patient was diagnosed with lung metastasis 11 months postoperatively.

Conclusions

The TNM classification provides significant prognostic information for Xp11.2 tRCC. A relatively active surveillance algorithm is recommended, and cytoreduction surgery is an effective approach for recurrent Xp11.2 tRCC. Larger studies are required to more extensively investigate the recurrence of these potentially aggressive tumors.

TFE3-positive renal cell carcinoma occurring in three children with dysfunctional kidneys on immunosuppression

Pediatric RCC is a rare pediatric neoplasm and is distinctly different compared to adult RCC, often demonstrating translocation morphology evidenced by unique histopathological features and TFE3 or TFEB nuclear expression. We report three cases of pediatric TFE3 positive RCC (TFE3-RCC) occurring in the setting of chronic kidney disease and long-term pharmacological immunosuppression, including two cases that developed in the native kidney following kidney transplantation. Together, these cases suggest that the kidney microenvironment in combination with immune dysregulation is likely contributing factors in the pathogenesis of some pediatric RCC, warranting further study. Long-term post-transplant surveillance may warrant screening for RCC.

A Review of Translocation T(6;11) Renal Cell Carcinoma Tumors in the Adult Patient

Historically, T(6;11) renal cell carcinoma (RCC) has been associated with the pediatric and adolescent populations and documentation of this tumor in adults has been rare. However, the frequency of translocation renal cell carcinoma (TRCC) may be widely underestimated in the adult population due to an inadequate immunohistochemical workup or misdiagnosis from similar gross and histological findings to other RCC. A subset of MiT family translocation carcinomas, t(6:11) (p21;q12) translocation tumors cause an alpha-TFEB gene fusion. Morphologically, this neoplasm tends to mimic the various types of RCC's, including clear cell, papillary, and even epitheloid angiomyolipomas. Adult cases of TRCC have shown to behave more aggressively than their indolent pediatric counterpart, but due to the limited number of reported cases the true nature of these tumors has yet to be determined. The aim of this review is to bring an awareness of translocation RCC to better understand its diagnoses, treatment and prognosis, and, in turn, to allow for new cases to further highlight the behavior of this rare variant.