Pediatric Renal Cell Carcinoma

Metabolic alterations in hereditary and sporadic renal cell carcinoma

Kidney cancer is the seventh leading cause of cancer in the world, and its incidence is on the rise. Renal cell carcinoma (RCC) is the most common form and is a heterogeneous disease comprising three major subtypes that vary in their histology, clinical course and driver mutations. These subtypes include clear cell RCC, papillary RCC and chromophobe RCC. Molecular analyses of hereditary and sporadic forms of RCC have revealed that this complex and deadly disease is characterized by metabolic pathway alterations in cancer cells that lead to deregulated oxygen and nutrient sensing, as well as impaired tricarboxylic acid cycle activity. These metabolic changes facilitate tumour growth and survival. Specifically, studies of the metabolic features of RCC have led to the discovery of oncometabolites - fumarate and succinate - that can promote tumorigenesis, moonlighting functions of enzymes, and substrate auxotrophy owing to the disruption of pathways that enable the production of arginine and cholesterol. These metabolic alterations within RCC can be exploited to identify new therapeutic targets and interventions, in combination with novel approaches that minimize the systemic toxicity of metabolic inhibitors and reduce the risk of drug resistance owing to metabolic plasticity.

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.

Immune Checkpoint Therapy Combinations in Adult Advanced MiT Family Translocation Renal Cell Carcinomas

BACKGROUND

There remains a paucity of data regarding the efficacy of immune checkpoint therapy (ICT) combinations ± vascular endothelial growth factor (VEGF) targeted therapy (TT) in translocation renal cell carcinoma (tRCC).

METHODS

This is a retrospective study of patients with advanced tRCC treated with ICT combinations at 11 centers in the US, France, and Belgium. Only cases with confirmed fluorescence in situ hybridization (FISH) were included. Objective response rates (ORR) and progression-free survival (PFS) were assessed by RECIST, and overall survival (OS) was estimated by Kaplan-Meier methods.

RESULTS

There were 29 patients identified with median age of 38 (21-70) years, and F:M ratio 0.9:1. FISH revealed TFE3 and TFEB translocations in 22 and 7 patients, respectively. Dual ICT and ICT + VEGF TT were used in 18 and 11 patients, respectively. Seventeen (59%) patients received ICT combinations as first-line therapy. ORR was 1/18 (5.5%) for dual ICT and 4/11 (36%) for ICT + VEGF TT. At a median follow-up of 12.9 months, median PFS was 2.8 and 5.4 months in the dual ICT and ICT + VEGF TT groups, respectively. Median OS from metastatic disease was 17.8 and 30.7 months in the dual ICT and ICT + VEGF TT groups, respectively.

CONCLUSION

In this retrospective study of advanced tRCC, limited response and survival were seen after frontline dual ICT combination therapy, while ICT + VEGF TT therapy offered some efficacy. Due to the heterogeneity of tRCC, insights into the biological underpinnings are necessary to develop more effective therapies.

Bilateral Native Kidney Papillary Renal Cell Carcinomas in a 11-Year-Old Renal Transplant Patient

Renal cell carcinomas (RCCs) are the most common renal tumors in adults and are usually sporadic and unilateral. Renal transplant recipients have an increased risk of developing RCC. RCC development after kidney transplantation is very rarely reported in children. We present a 11-year-old boy who had cadaveric kidney transplantation for kidney failure 2 years ago. He was under immunosuppressive therapy and presented with microscopic hematuria. An ultrasound (US) revealed bilateral solid renal masses. Further cross-sectional imaging showed a 60 × 70 × 60-mm right renal mass with claw sign and a 5 × 6 × 6-mm mass in the left renal lower pole. A bilateral radical nephroureterectomy of native kidneys was performed. The pathology revealed bilateral papillary RCC without TFE3 upregulation. The patient was kept on low-dose immunosuppressive therapy in the perioperative period. He received no chemotherapy but a close radiological surveillance was undertaken. He is tumor-free 2 years after the operation. RCC is a rare tumor for children and bilateralism is even rarer. The child had a history of chronic kidney disease, peritoneal dialysis, and immunosuppressive therapy. As there are no standardized protocols regarding imaging in transplanted kidneys routine surveillance, US follow-up should also focus on detecting malignancy.

Beyond Wilms tumor: imaging findings and outcomes of rare renal tumors in children

BACKGROUND

Compared to Wilms, non-Wilms renal tumors in children are less well understood due to their rare occurrence which limits precise definition of the typical imaging patterns.

OBJECTIVE

This study aims to identify distinctive imaging findings, demographic characteristics and prognosis of pediatric non-Wilms renal tumors.

MATERIALS AND METHODS

From January 2007 to December 2018, 207 patients with a diagnosis of primary kidney neoplasia were yielded from our radiology archive, 171 of whom were diagnosed with Wilms tumor, 4 with angiomyolipoma and one with nephrogenic rest. The remaining 31 patients with a diagnosis of primary kidney neoplasia were enrolled in this retrospective study. Imaging data, age, gender, prognosis and findings regarding follow-up were noted.

RESULTS

Eight patients had renal cell carcinoma, seven had clear cell sarcoma, six had mesoblastic nephroma, four had rhabdoid tumor, three had desmoplastic small round cell tumor, two had cystic nephroma and one had metanephric stromal tumor. The age of diagnosis was > 8 years for renal cell carcinoma and desmoplastic small round cell tumor, < 5 years for rhabdoid tumor and < 7 months for mesoblastic nephroma. There was no gender preference for any tumor type. The prognosis for rhabdoid tumor was extremely poor in that all the patients followed up in our institute were deceased, whereas no recurrence was found in other tumors. Translocation type renal cell carcinoma had lower T2-weighted signal intensity, mesoblastic nephroma was a predominantly cystic mass, clear cell sarcoma was generally larger at presentation and extensive amorphous calcifications were seen in desmoplastic small round cell tumor.

CONCLUSION

For the differential diagnosis of pediatric non-Wilms renal tumors, age is the most important factor, followed by propensity to metastasize/aggressive behavior of the mass. Knowledge of specific imaging findings of these tumors may help to narrow the differential diagnosis.

How we approach paediatric renal tumour core needle biopsy in the setting of preoperative chemotherapy: A Review from the SIOP Renal Tumour Study Group

The International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) advocate treating children with Wilms tumour (WT) with preoperative chemotherapy, whereas the Renal Tumor Committee of the Children's Oncology Group (COG) advocates primary nephrectomy (without biopsy) when feasible. Successive SIOP-RTSG trial protocols recommended pretreatment biopsy of children with unilateral tumours only where there were features to suggest an increased probability of a non-WT requiring a change in management. The UK experience in the SIOP WT 2001 trial showed that an alternate approach of performing biopsies on all children with renal tumour masses to determine histology at diagnosis rarely changes management, and can result in misdiagnosis (particularly patients in the age range typical for WT). Although a more selective approach to biopsy has been routine practice in all other countries participating in SIOP-RTSG trials, there was variation between national groups. To address this variation and provide evidence-based recommendations for the indications and recommended approach to renal tumour biopsy within the SIOP paradigm, an international, multidisciplinary working group of SIOP-RTSG members was convened. We describe the resulting recommendations of this group, which are to be incorporated in the ongoing SIOP-RTSG UMBRELLA study.

Precision Medicine: An Optimal Approach to Patient Care in Renal Cell Carcinoma

Renal cell cancer (RCC) is a heterogeneous tumor that shows both intra- and inter-heterogeneity. Heterogeneity is displayed not only in different patients but also among RCC cells in the same tumor, which makes treatment difficult because of varying degrees of responses generated in RCC heterogeneous tumor cells even with targeted treatment. In that context, precision medicine (PM), in terms of individualized treatment catered for a specific patient or groups of patients, can shift the paradigm of treatment in the clinical management of RCC. Recent progress in the biochemical, molecular, and histological characteristics of RCC has thrown light on many deregulated pathways involved in the pathogenesis of RCC. As PM-based therapies are rapidly evolving and few are already in current clinical practice in oncology, one can expect that PM will expand its way toward the robust treatment of patients with RCC. This article provides a comprehensive background on recent strategies and breakthroughs of PM in oncology and provides an overview of the potential applicability of PM in RCC. The article also highlights the drawbacks of PM and provides a holistic approach that goes beyond the involvement of clinicians and encompasses appropriate legislative and administrative care imparted by the healthcare system and insurance providers. It is anticipated that combined efforts from all sectors involved will make PM accessible to RCC and other patients with cancer, making a tremendous positive leap on individualized treatment strategies. This will subsequently enhance the quality of life of patients.

Tumor Lipids of Pediatric Papillary Renal Cell Carcinoma Stimulate Unconventional T Cells

Papillary renal cell carcinoma (PRCC) is a rare entity in children with no established therapy protocols for advanced diseases. Immunotherapy is emerging as an important therapeutic tool for childhood cancer. Tumor cells can be recognized and killed by conventional and unconventional T cells. Unconventional T cells are able to recognize lipid antigens presented via CD1 molecules independently from major histocompatibility complex, which offers new alternatives for cancer immunotherapies. The nature of those lipids is largely unknown and α-galactosylceramide is currently used as a synthetic model antigen. In this work, we analyzed infiltrating lymphocytes of two pediatric PRCCs using flow cytometry, immunohistochemistry and qRT-PCR. Moreover, we analyzed the CD1d expression within both tumors. Tumor lipids of PRCC samples and three normal kidney samples were fractionated and the recognition of tumor own lipid fractions by unconventional T cells was analyzed in an in vitro assay. We identified infiltrating lymphocytes including γδ T cells and iNKT cells, as well as CD1d expression in both samples. One lipid fraction, containing ceramides and monoacylglycerides amongst others, was able to induce the proliferation of iNKT cells isolated from peripheral blood mononuclear cells (PBMCs) of healthy donors and of one matched PRCC patient. Furthermore, CD1d tetramer stainings revealed that a subset of iNKT cells is able to bind lipids being present in fraction 2 via CD1d. We conclude that PRCCs are infiltrated by conventional and unconventional T cells and express CD1d. Moreover, certain lipids, present in pediatric PRCC, are able to stimulate unconventional T cells. Manipulating these lipids and T cells may open new strategies for therapy of pediatric PRCCs.

Twenty children with non-Wilms renal tumors from a reference center in Central Anatolia, Turkey

Background/aim

Non-Wilms renal tumors (NWRTs) are rarely encountered in children. The aim of this study is to determine the treatment strategies, prognosis, outcomes, and survival of children with NWRTs at Erciyes University in Kayseri, Turkey.

Materials and methods

Medical records of all patients (n = 20) treated for NWRTs over a 23-year period (1995–2018) were reviewed retrospectively.

Results

There was male predominance (female/male: 7/13); the median age at diagnosis was 3.2 years old (0.1–13.5 years old). The major histological groups included mesoblastic nephroma (MBN), (n: 5, 25%), malignant rhabdoid tumor (MRT), (n: 5, 25%), renal cell carcinoma, (n: 3, 15%), inflammatory myofibroblastic tumor (n: 2, 10%), multilocular cystic renal tumors (n: 2, 10%), metanephric adenoma (n: 1, 5%), renal neuroblastoma (n: 1, 5%), and bilateral renal Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) (n: 1, 5%). All of the patients with NWRTs had radical nephrectomy except the child with bilateral renal ES/PNET. Six children died because of progressive disease; the mortality rate was 30% (n: 6).

Conclusion

We have made the first report of bilateral renal involvement of ES/PNET in the English medical literature. Physicians dealing with pediatric renal masses should be alert to the high mortality rate in children with MRT, MBN, and ES/PNET and they should design substantial management plans for NWRTs.

Pediatric renal cell carcinoma

PURPOSE OF REVIEW

To review the presentation, natural history and treatment of renal cell carcinoma in children and young adults with renal cell carcinoma (RCC).

RECENT FINDINGS

Complete resection of lymph nodes at the time of tumor resection can improve clinical outcomes and limit the need for adjuvant chemotherapy. Genetic alterations that lead to translocation tumors are a therapeutic target of receptor tyrosine kinase inhibitors.

SUMMARY

The incidence of RCC increases with age. Unlike adult patients, young patients with RCC present symptomatically and at higher stage and grade. Translocation tumors predominate RCC in children with biologic activity characterized by early spread to lymph nodes with small primary tumors. Preoperative imaging is poorly sensitive for positive lymph nodes; as such, surgeons should have a low threshold for lymph node sampling during tumor resection. Despite the advanced stage at presentation, the prognosis in children is more favorable than their adult counterparts. Complete resection of lymph nodes at the time of surgical resection improves patient prognosis. Chemotherapy targeting the PI3/AKT pathway has demonstrated clinical benefit.

Early onset renal cell carcinoma in an adolescent girl with germline FLCN exon 5 deletion

Birt-Hogg-Dube (BHD) disease is an autosomal dominant cancer syndrome characterized by benign skin tumors, renal cancer and spontaneous pneumothorax and is caused by mutations in the Folliculin (FLCN) gene. Benign skin tumors and pneumothorax occur in the majority of patients affected by BHD syndrome, but only 30-45% of them develop renal cell carcinoma (RCC) with a median age of diagnosis at 48. The earliest onset of RCC in a BHD patient has been reported at age 20. Here we report a case of a 14 year-old patient with germline FLCN mutation leading to an early-onset bulky RCC that could not be classified strictly according to existing histological types. Germline genetic testing revealed a deletion at FLCN exon 5. The father of the patient was identified as the asymptomatic carrier. We report the youngest patient with BHD-related RCC. This early onset presentation supports genetic testing of at-risk patients and initiation of imaging surveillance for RCC in early adolescence. In addition, future studies are necessary to understand the determinants of reduced penetrance in BHD disease.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Clinical efficacy of cabozantinib in two pediatric patients with recurrent renal cell carcinoma

Advanced-stage renal cell carcinoma (RCC) carries a dismal prognosis for pediatric patients with few studied therapeutic options. Cabozantinib is a small molecule tyrosine kinase inhibitor against the oncoprotein MET. It is currently approved by the U.S. Food and Drug administration for second-line treatment of RCC in adults. There is no published data on its use in children with RCC. We report here two pediatric patients with recurrent metastatic RCC whose tumors expressed MET and were treated with cabozantinib. Both patients had significant disease regression and symptomatic improvement for over 15 months with tolerable adverse effects. Cabozantinib can maintain prolonged disease control in pediatric RCC and warrants further study.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Adult Renal Cell Carcinoma: A Review of Established Entities from Morphology to Molecular Genetics

According to the current World Health Organization (WHO), renal cell carcinomas (RCCs) that primarily affect adults are classified into 8 major subtypes. Additional emerging entities in renal neoplasia have also been recently recognized and these are discussed in further detail by Mehra et al (Emerging Entities in Renal Neoplasia, Surgical Pathology Clinics, 2015, Volume 8, Issue 4). In most cases, the diagnosis of a RCC subtype can be based on morphologic criteria, but in some circumstances the use of ancillary studies can aid in the diagnosis. This review discusses the morphologic, genetic, and molecular findings in RCCs previously recognized by the WHO, and provides clues to distinction from each other and some of the newer subtypes of RCC. As prognosis and therapeutic options vary for the different subtypes of RCC, accurate pathologic distinction is critical for patient care.

TFE3-positive renal cell carcinomas are not always Xp11 translocation carcinomas: Report of a case with a TPM3-ALK translocation

Translocation-associated renal cell carcinoma (RCC) is a distinct subtype of RCC with gene rearrangements of the TFE3 or TFEB loci. The TFE3 gene is located at Xp11 and can fuse to a number of translocation partners, resulting in high nuclear expression of TFE3 protein. TFE3 immunostaining is often used as a surrogate marker for a TFE3 translocation. We report a case of an RCC that expressed TFE3 but showed only gain of TFE3 rather than a translocation. Moreover, this case had a t(1;2) translocation fusing ALK and TMP3, identical to that seen in inflammatory myofibroblastic tumour. There was resulting overexpression of ALK protein in a cytoplasmic and membranous pattern. The patient was not treated with chemotherapy but following regional nodal recurrence, an ALK inhibitor was added and the patient remains alive one year later. There are only rare reports of RCC with an ALK-TMP3 fusion, and these tumours can express TFE3 on some unknown basis not related to a TFE3 translocation. Any RCC positive for TFE3 and lacking a translocation should be tested for ALK expression and translocation. Recognition of this subtype of RCC will allow ALK inhibitor therapy to be added, in the hope of improving patient outcome.

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.

Pediatric Papillary Renal Cell Carcinoma in a Horseshoe Kidney: A Case Report with Review of the Literature

Renal cell carcinoma is the most common malignancy of the kidney in adults. In children, however, it only accounts for an estimated 1.8 to 6.3% of all pediatric malignant renal tumors. Papillary renal cell carcinoma is the second most common type of renal cell carcinoma in children. We present the case of a 12-year-old boy with a 2-month history of abdominal pain, unexplained weight loss, and gross hematuria. Computed tomography revealed a horseshoe kidney and a well-defined mass of 4 cm arising from the lower pole of the right kidney. Microscopically the tumor was composed of papillae covered with cells with abundant eosinophilic cytoplasm and high-grade nuclei with prominent nucleoli. Immunohistochemistry was performed; EMA, Vimentin, and AMACR were strongly positive while CK7, CD10, RCC antigen, TFE3, HMB-45, and WT-1 were negative. Currently, 10 months after the surgical procedure, the patient remains clinically and radiologically disease-free.

Atypical presentation of calvarial metastasis of renal cell carcinoma in an adolescent: A rare case diagnosed on fine needle aspiration cytology with literature review

Renal cell carcinoma (RCC) is a complex and challenging neoplasm both in terms of treatment as well as diagnosis. Its unpredictable biological behavior and many deceptive appearances can sometimes bewilder the pathologist. We hereby report a rare case of a 17 year old girl presenting with an occipital swelling and importantly no prior documents at the time of aspiration. Fine needle aspiration cytology showed features of metastatic carcinoma with the following possibilities; metastatic RCC, melanoma, and hepatocellular carcinoma. Further detailed history of the patient and investigations were advised. Intraoperative squash smears also showed similar features. Histopathology of the lesion showed features of metastatic RCC. This case highlights the fact that a skull lesion in rare cases may be the presenting sign of an underlying malignancy. In the absence of key documents, providing the correct diagnosis may become very challenging and cytomorphology alone can be extremely helpful.

An approach to renal masses in pediatrics

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.

Differential diagnosis of renal tumors with tubulopapillary architecture in children and young adults: a case report and review of literature

BACKGROUND

Tumors of the kidney are uncommon in children and young adults. Accurate classification is crucial for both prognostication and therapeutic intervention. However, majority of the tumors in this age group have unusual morphology that renders classification challenging. Tubulopapillary architecture is one of the most common morphological patterns observed in renal tumors of children and young adults.

METHODS

A patient with epithelial predominant Wilms tumor was reported. Differential diagnosis of renal tumors with tubulopapillary morphology was discussed with an emphasis on the histological and immunohistochemical features, and the literature was reviewed.

RESULTS

A 25 year-old female patient presented with bilateral multilocular cystic masses. She underwent right radical nephrectomy and left partial nephrectomy. The pathological examination revealed a tumor with tubulopapillary architecture which was lined with low columnar epithelial cells. During the work-up of this case, several entities were considered and ruled out by careful gross, microscopic examination and prudent use of immunohistochemistry. The tumor cells were positive for WT-1, and variably positive for cytokeratin AE1/3, CD56, CD57, and negative for cytokeratin 7 and EMA. Fluorescent in-situ hybridization revealed no gain of chromosome 7 and 17. A diagnosis of epithelial predominant adult Wilms tumors was rendered for both kidneys. The patient received systemic chemotherapy and radiation to the remnant left kidney and was free of disease three years after the initial surgery.

CONCLUSION

The differential diagnosis of renal tumors with tubulopapillary features in children and young adults include papillary renal cell carcinoma, metanephric adenoma, epithelial predominant Wilms tumor, translocation renal cell carcinoma and metastatic adenocarcinoma to the kidney. An accurate classification relies on careful examination of clinical and pathological features and immunohistochemical characteristics.

Clinical implications of current developments in genitourinary pathology

CONTEXT

Several developments in genitourinary pathology are likely to change our understanding and management of some genitourinary cancers considerably.

OBJECTIVE

To review 5 stories in genitourinary pathology: (1) fusion in the ETS (E26) gene family in prostatic adenocarcinoma; (2) insulin-like growth factor II messenger RNA-binding protein 3 (IMP3), an important prognostic biomarker for kidney and bladder cancers; (3) translocation renal cell carcinoma; (4) UroVysion fluorescence in situ hybridization test in urine cytology for detection of bladder cancer; and (5) the use of triple immunostaining for diagnosis of prostate cancer.

DATA SOURCES

Literature review and authors' personal experiences.

CONCLUSIONS

Many scientific findings have contributed recently to the understanding of the natural pathogenesis and progression of genitourinary cancers. This translational research helps in diagnosing, predicting, and potentially, treating genitourinary cancers.

Radiologic-pathologic correlation of renal cell carcinoma associated with Xp11.2 translocation

BACKGROUND

The prognosis of translocation RCCs in adult patients is relatively poor compared to that of other subtypes of RCCs. Although there have been several reports regarding radiologic findings of translocation RCC, studies with histologic correlation could help to understand the imaging features.

PURPOSE

To explore the correlation between radiologic and pathologic findings in Xp11.2 translocation renal cell carcinoma (RCC) and provide clues for translocation RCC diagnosis.

MATERIAL AND METHODS

CT scans of six patients (one man and five women; age range, 8-71 years; mean age, 34 years) with histologically-proven Xp11.2 translocation RCCs were retrospectively evaluated in consensus by two radiologists. Tumor size, presence of necrosis, hemorrhage, fat or calcification, enhancement patterns of the tumor, presence of lymphadenopathy, and distant metastases were evaluated.

RESULTS

The average size of the tumors was 6 cm (range, 2.7-12 cm). All six tumors appeared as well-defined masses with areas of low attenuation representing hemorrhage or necrosis. Four tumors contained high attenuating solid portions, compared to the surrounding renal cortex seen on unenhanced images, where representing dense cellular component on microscopic examination. Peripheral rim enhancement pattern that correlated with histologic finding of a fibrous capsule was seen in five cases. In two patients who underwent kidney MR, the masses showed low signal intensity on T2-weighted images. One patient had lymphadenopathy. No distant metastasis was noted in any patient.

CONCLUSION

Translocation RCC appeared as a well-defined mass that contain high attenuating solid portions on unenhanced images and low attenuating necrotic or hemorrhagic foci; the tumor also showed gradual peripheral rim enhancement due to a fibrous capsule surrounding the tumor.