Renal cell carcinomas in children and young adults: increased incidence of papillary architecture and unique subtypes

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.

Clinicopathological Features and Survival Data of Localized Renal Masses in Young Adults

Purpose:

Renal tumors are rarely seen in young adults. In this study, was aimed to report the data of 18-40 years old patients with Renal Cell Carcinoma (RCC) whom we operated.

Material and Method:

We retrospectively reviewed the data of patients between the ages of 18 and 40 years old patients who have renal masses. All patients were evaluated with chest X-ray, Computed tomography (CT) and/or MRI. Radical or partial nephrectomy was performed for clinical localized masses with malignancy suspicion. Clinicopathological features and survival data of all the patients were recorded. In the follow-up protocol routine blood tests, chest X-ray and abdominal CT were used.

Results:

A total of 42 patients, [22 (52.4%) male and 20 (47.6%) female], with a mean age of 34.48 (range 18 to 40) were included in the study. Of these, 32 (%76) had RCC and 10 (24%) had benign pathologies. Female patients had more benign pathology (35% vs 13.6%). The most commonly subtype of RCC (n = 22% 69) was clear cell RCC (cRCC), while the most common benign mass was oncocytoma (n = 4% 40). At the mean follow-up period of 42.34 months, overall survival rate was found to be 93.8%.

Conclusion:

Young adults with localized renal mass have benign pathology in a considerable rate. All of the malign masses in this population have low Furhman grade (1 or 2).

Bilateral Xp11.2 translocation renal cell carcinoma: a case report

Background

Xp11.2 translocation renal cell carcinoma (RCC) is a rare variety of a kidney neoplasm. We report a case of bilateral Xp11.2 translocation RCC occurring metachronously and discuss this very rare entity with reference to the literature.

Case presentation

The patient was a 56-year-old woman who presented with a right renal tumor. The patient had undergone left radical nephrectomy 7 years previously, which resulted in a histopathological diagnosis of clear cell RCC. Open right partial nephrectomy was performed under the presumptive diagnosis of recurrence of clear cell RCC. The present right renal tumor was pathologically diagnosed Xp11.2 translocation RCC. More than 70% of the tumor cells in the present right tumor were strongly positive for transcription factor E3 (TFE3) expression by immunohistochemical analysis with an anti-TFE3 antibody. A break-apart of the TFE3 genes in the bilateral tumors was identified by fluorescence in situ hybridization analysis. Real time-polymerase chain reaction analysis for the alveolar soft part sarcoma locus-TFE3 fusion gene was performed, which gave a positive result in the bilateral tumors. Pathological comparison of each of the tumors might lead to a final diagnosis of Xp11.2 translocation RCC occurring metachronously.

Conclusions

We present the bilateral Xp11.2 translocation RCC. A combination of immunohistochemical, cytogenetic and molecular biological approaches allowed the final diagnosis of such a rare RCC.

Re-evaluation of 33 'unclassified' eosinophilic renal cell carcinomas in young patients

AIMS

We sought to determine if some unclassified renal cell carcinomas (RCCs) in children and young adults that are characterised by predominantly eosinophilic cytoplasm are related to the recently described succinate dehydrogenase (SDH)-deficient RCC, fumarate hydratase (FH)-deficient RCC or eosinophilic solid and cystic (ESC) RCC.

METHODS AND RESULTS

We reviewed 33 unclassified RCCs with predominantly eosinophilic cytoplasm in patients aged 35 years or younger. Immunohistochemistry (IHC) for SDHB, FH and CK20 (a marker of ESC) was performed in all cases. IHC for 2-succinocysteine (2SC) was performed on RCC with loss of FH labelling. Four RCC (12%) (median age 18 years) demonstrated loss of FH labelling as well as aberrant 2SC labelling, and were thus classified as FH-deficient RCCs. Importantly, none of these cases demonstrated the characteristic macronucleoli typical of FH-deficient RCC. Eight RCC (24%) (median age 20.5 years) demonstrated loss of SDHB and were reclassified as SDH-deficient RCCs. Importantly, only four of eight SDH-deficient RCC demonstrated the characteristic cytoplasmic vacuoles and inclusions of typical SDH-deficient RCC. Ten RCC (30%) (median age 27 years) were reclassified as ESC RCCs. Four of 10 ESC RCC were multifocal (one bilateral), four of 10 ESC RCC occurred in males and one patient presented with liver and lung metastases, all not described previously in ESC. Eleven RCC (33%) remained unclassified.

CONCLUSIONS

Pathologists should have a low threshold for performing FH, SDHB and CK20 IHC when confronted with unclassified eosinophilic RCC or 'oncocytoma' in young patients.

[Renal cell carcinomas in childhood]

BACKGROUND

Renal cell carcinoma is a rare childhood disease. However, it should be considered in the differential diagnosis in the detection of a renal mass.

OBJECTIVES

Incidence and mortality of renal cell carcinomas in childhood. Presentation of clinical symptoms, diagnostics, histology, therapy and course of the disease.

PATIENTS AND METHODS

Evaluation of our own prospective data of a small patient population of 8 patients, as well as discussion of the current literature on this tumor entity.

RESULTS

The average follow-up period was 27 months. Preoperative staging studies showed no metastases. The histologically primary predominant subtype was papillary renal cell carcinoma. Tumor stage and lymph node status were the most important prognostic factors in our study.

CONCLUSIONS

Renal cell carcinoma in childhood is a rare disease whose treatment is challenging and should be performed in an interdisciplinary team. Typical clinical symptoms, as in adults, are absent. The partial nephrectomy should be, if practicable, the surgical treatment of choice. The most important risk factors for survival are tumor stage and lymph node status. Data on adjuvant target therapy for metastatic disease in childhood are lacking. Further prospective, multicenter studies are necessary to generate more information on the biology and course of this disease and to obtain adjuvant treatment options in locally advanced disease.

Pediatric Clear Cell Renal Cell Carcinoma with Pelvicalyceal System Invasion and Contiguous Extension Upto Bladder: Novel and Bizarre Tumor Behaviour

Background

Paediatric renal cell carcinoma (RCC) is a rare neoplasm which differs significantly in its clinico-pathological behaviour from the adult variant. The clear cell variant constitutes a relatively small histological subset of this neoplasm.

Case Report

We present a very unusual, pathologically proven case of clear cell variety of pediatric RCC which showed invasion into the pelvicalyceal system with contiguous extension up to the urinary bladder. Such a novel manifestation of paediatric RCC has not been described previously in literature. A relevant review of literature is included.

Conclusions

The aggressive biological behaviour of the paediatric RCC in our case and the consequent atypical imaging findings are distinctly unusual. These findings may represent a new aggressive variant of this rare neoplasm. The radiologist and clinician should be aware of these novel manifestations of paediatric clear cell RCC.

Laparoscopic Partial Nephrectomy for Renal-Cell Carcinoma During Pregnancy

BACKGROUND

The incidence of renal-cell carcinoma (RCC) is low during pregnancy. There are different approaches for timing of surgery and treatment modalities for RCC in pregnant women in the literature. To our knowledge, this is the first laparoscopic partial nephrectomy case in a pregnant woman.

CASE PRESENTATION

Herein, we present a 34-year-old woman with a renal mass at her 14th gestational week. She was admitted to our clinic after a right renal mass was incidentally diagnosed during routine antenatal ultrasonography. MRI revealed a completely endophytic tumor of 6 × 6.5 × 6.5 cm, located in the upper half of the right kidney. We performed laparoscopic partial nephrectomy in our patient and the postoperative course was uneventful.

CONCLUSION

This is the first presented laparoscopic partial nephrectomy case in a pregnant patient. Nephron-sparing surgeries can be performed laparoscopically in appropriate sized renal tumors in suitable pregnant patients.

Validation and utilization of a TFE3 break-apart FISH assay for Xp11.2 translocation renal cell carcinoma and alveolar soft part sarcoma

Background

Xp11.2 or TFE3 translocation renal cell carcinomas (RCC) and alveolar soft part sarcoma (ASPS) are characterized by chromosome translocations involving the Xp11.2 breakpoint resulting in transcription factor TFE3 gene fusions. The most common translocations documented in TFE3 RCCs are t(X;1) (p11.2;q21) and t(X;17) (p11.2;q25) which leads to fusion of TFE3 gene on Xp11.2 with PRCC or ASPL respectively. TFE3 immunohistochemistry (IHC) has been inconsistent over time due to background staining problems in part related to fixation issues. Karyotyping to detect TFE3 gene rearrangement requires typically unavailable fresh tissue. Reverse transcriptase-polymerase chain reaction (RT-PCR) is generally very challenging due to degradation of RNA in archival material. The study objective was to develop and validate a TFE3 break-apart fluorescence in situ hybridization (FISH) assay to confirm Xp11 translocation RCCs and ASPS.

Methods

Representative sections of formalin-fixed paraffin-embedded tissue blocks were selected in 40 possible cases. Approximately 60 tumor cells were analyzed in the targeted region. The validation of TFE3 FISH was done with 11 negative and two positive cases. Cut off for a positive result was validated as >7.15 % positive nuclei with any pattern of break-apart signals. FISH evaluation was done blinded of the immunohistochemical or karyotype data.

Results

Three out of forty cases were positive for the TFE3 break-apart signals by FISH. The negative cases were reported as clear cell RCC with papillary features (10), clear cell RCC with sarcomatoid areas (2), Papillary RCC with clear cell areas (9), Chromophobe RCC (2), RCC, unclassified type (3) and renal medullary carcinoma (1). 3 of the negative cases were consultation cases for renal tumor with unknown histology. Seven negative cases were soft tissue tumor suspicious for ASPS.

Conclusion

Our study validates the utility of TFE3 break-apart FISH on formalin-fixed paraffin-embedded tissue sections for diagnosis and confirmation of Xp11.2 translocation RCCs and ASPS.

The relationship between histopathology and age factor in patients who were operated for renal masses

OBJECTIVE

Renal neoplasms have a predilection to occur in older patients and they are often malignant. They may have different structural characteristics according to age groups. In our study, we have investigated age-related demographic characteristics of the patients who were operated because of suspected malignant renal masses.

MATERIALS AND METHODS

Between 2010 and 2014, 129 patients were treated surgically for suspected malignant renal masses at our institution. These cases had undergone open radical, open partial, and laparoscopic radical nephrectomies. Patients were divided into two groups based on their ages and evaluated accordingly as Group 1 (≤50 years) and Group 2 (>50 years). Groups were compared based on their clinical and pathological features.

RESULTS

Group 1 and Group 2 consisted of 29 (22.4%) and 91 (77.6%) patients, respectively. The mean age of younger patients was 43.1 years (23-49 years), with a male to female ratio of 19/10, while the average tumor size was 57.6 mm (20-120 mm). Twenty-four patients (83%) had a malignant pathology and five patients (17%) had a benign pathology. Clear cell carcinoma was diagnosed in 67% of the patients in both groups. There was no significant difference with respect to age and tumor size of male and female patients in the younger age group, while younger female adults tended to have a more benign pathology than their male counterparts (40% and 5%, respectively, p<0.05).

CONCLUSION

There was no significant difference with respect to gender, tumor size, laterality, and surgical and pathologic features between younger and older patients. An organ- sparing approach should be strongly considered when treatment for renal tumors in young females is performed because of a potentially higher incidence of a benign pathology of renal masses.

A rare cause of childhood renal cysts: Xp11.2 translocation renal cell carcinoma

Pediatric renal cysts are rare, usually asymptomatic and incidentally detected in children. Cyst associated renal cell carcinoma (RCC) or cystic RCC is extremely rare in children. Bosniak classification system has been accepted for the management of cystic renal masses. Xp11.2 translocation RCC is a recently classified distinct subtype and usually affects children and adolescents. We report the case of a 10-year-old girl with Xp11.2 translocation RCC from a cyst of the right kidney.

Renal cell carcinoma in children, adolescents and young adults: a National Cancer Database study

PURPOSE

We compared the presentation and outcomes of patients younger than 21 years with renal cell carcinoma and determined risk factors associated with mortality.

MATERIALS AND METHODS

We searched the National Cancer Database for patients diagnosed with renal cell carcinoma between 1998 and 2011. We evaluated patients younger than 30 years with renal cell carcinoma, including clear cell, chromophobe, papillary and not otherwise specified subcategories. We used logistic regression to compare presenting cancer, demographics and treatment variables in patients 0 to 15 years, 15 to 21 years and 21 to 30 years old. Cox regression analysis was used to determine risk factors for mortality in patients younger than 21.

RESULTS

Of 3,658 patients younger than 30 years included in the study 161 were younger than 15 and 337 were 15 to 21 years old. A higher proportion of younger patients had renal cell carcinoma not otherwise specified and papillary histology compared to those 21 to 30 years (p < 0.001). Younger patients presented with higher stage (p < 0.0001), higher grade (p < 0.0001) and larger tumors (p < 0.0001) than those 21 to 30 years. A higher percentage of younger patients underwent lymph node dissection (p < 0.0001) or chemotherapy as first-line treatment (p < 0.0001) compared to those 21 to 30 years. Cox regression analysis demonstrated that stage 4 presentation, government insurance status, nonchromophobic pathology results and not undergoing surgery as first-line treatment were independently associated with increased mortality in patients younger than 21 years.

CONCLUSIONS

Children and adolescents with renal cell carcinoma present with more advanced disease than those 21 to 30 years old. In patients younger than 21 years mortality was associated with the nonchromophobe histological subtype, stage 4 disease, government insurance and not undergoing surgery as first-line therapy.

Clinical heterogeneity of Xp11 translocation renal cell carcinoma: impact of fusion subtype, age, and stage

Xp11 translocation renal cell carcinomas harbor chromosome translocations involving the Xp11 breakpoint, resulting in gene fusions involving the TFE3 gene. The most common subtypes are the ASPSCR1-TFE3 renal cell carcinomas resulting from t(X;17)(p11;q25) translocation, and the PRCC-TFE3 renal cell carcinomas, resulting from t(X;1)(p11;q21) translocation. A formal clinical comparison of these two subtypes of Xp11 translocation renal cell carcinomas has not been performed. We report one new genetically confirmed Xp11 translocation renal cell carcinoma of each type. We also reviewed the literature for all published cases of ASPSCR1-TFE3 and PRCC-TFE3 renal cell carcinomas and contacted all corresponding authors to obtain or update the published follow-up information. Study of two new, unpublished cases, and review of the literature revealed that 8/8 patients who presented with distant metastasis had ASPSCR1-TFE3 renal cell carcinomas, and all but one of these patients either died of disease or had progressive disease. Regional lymph nodes were involved by metastasis in 24 of the 32 ASPSCR1-TFE3 cases in which nodes were resected, compared with 5 of 14 PRCC-TFE3 cases (P=0.02).; however, 11 of 13 evaluable patients with ASPSCR1-TFE3 renal cell carcinomas who presented with N1M0 disease remained disease free. Two PRCC-TFE3 renal cell carcinomas recurred late (at 20 and 30 years, respectively). In multivariate analysis, only older age or advanced stage at presentation (not fusion subtype) predicted death. In conclusion, ASPSCR1-TFE3 renal cell carcinomas are more likely to present at advanced stage (particularly node-positive disease) than are PRCC-TFE3 renal cell carcinomas. Although systemic metastases portend a grim prognosis, regional lymph node involvement does not, at least in short-term follow-up. The tendency for PRCC-TFE3 renal cell carcinomas to recur late warrants long-term follow-up.

13-year-old tuberous sclerosis patient with renal cell carcinoma associated with multiple renal angiomyolipomas developing multifocal micronodular pneumocyte hyperplasia

BACKGROUND

The autosomal dominant tumor syndrome tuberous sclerosis complex is caused by the mutated TSC1 gene, hamartin, and the TSC2 gene, tuberin. Patients with this complex develop typical cutaneus symptoms such as peau chagrin or angiofibromas of the skin as well as other lesions such as astrocytomas in the brain and lymphangioleiomyomatosis in the lung. Only a few tuberous sclerosis patients have been described who showed a multifocal micronodular pneumocyte hyperplasia of the lung. Another benign tumor which often occurs together with tuberous sclerosis is the angiomyolipoma of the kidney. Furthermore, an increased incidence of renal cell carcinoma in connection with tuberous sclerosis has also been proven.

CASE PRESENTATION

We report a 13-year-old white girl with epilepsy and hypopigmented skin lesions. Radiological studies demonstrated the typical cortical tubers leading to the diagnosis of tuberous sclerosis. In the following examinations a large number of angiomyolipomas were found in both kidneys. One lesion showed an increasing size and tumor like aspects in magnetic resonance imaging. The pathological examination of the following tumorectomy demonstrated an unclassified renal cell carcinoma. Four months postoperatively, a follow-up computer tomography revealed multiple bilateral pulmonary nodules. To exclude lung metastases of the renal cell carcinoma, multiple open-lung biopsies were performed.

CONCLUSION

Here we report a diagnostically challenging case of a 13-year-old patient with tuberous sclerosis and angiomyolipomas of the kidney who developed an unclassified renal cell carcinoma as well as multifocal micronodular pneumocyte hyperplasia.

CT and MRI appearances and radiologic staging of pediatric renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is an uncommon but noteworthy primary pediatric renal malignancy. There is a paucity of published data regarding the CT/MRI appearances and accuracy of pretreatment radiologic staging of this form of cancer in children.

OBJECTIVE

To review the various CT/MRI appearances of pediatric RCC and assess the accuracy of pretreatment radiologic staging using these imaging modalities.

MATERIALS AND METHODS

Institutional Departments of Pathology and Radiology records were searched from 1995 through 2010 for children (younger than 18 years of age) with RCC. Available pretreatment contrast-enhanced abdominopelvic CT and MRI examinations were reviewed by two radiologists. Pertinent imaging findings were documented by consensus, and correlation was made between radiologic and surgicopathological TNM staging.

RESULTS

Pretreatment imaging studies from 10 RCCs in nine children (four girls and five boys; mean age 12.9 years) were reviewed. The mean size of the primary tumor was 6.2 cm (range, 1.5-12.6 cm). Ninety percent of RCCs demonstrated heterogeneous postcontrast enhancement. Fifty percent of masses had associated hemorrhage, while 40% contained internal calcification. Regarding TNM staging, N staging was correct for 10 of 10 tumors, while M staging was correct for 10 of 10 tumors. Imaging correctly staged only 4 of 10 tumors with respect to T stage. Radiologic and surgicopathological overall staging were concordant for 8 of 10 tumors.

CONCLUSION

Pediatric RCCs typically present as large, heterogeneous masses, and they commonly hemorrhage and contain internal calcification. Radiologic and surgicopathological overall TNM staging are frequently concordant, although radiologic T staging is often incorrect.

Histopathology of surgically treated renal tumours in young adults: a developing country perspective

BACKGROUND

There is no data on the histopathological characteristics of renal tumours in young adults in Pakistan.

MATERIALS AND METHODS

We retrospectively analysed 133 young adults (age: 16 to ≤40 years) who underwent nephrectomy for suspected renal cancer from 1994 till July 2010. The demographical and pathological parameters were determined from original surgical biopsy reports and case files, and analysed.

RESULTS

The mean age of patients was 33.3 ± 6.2 years. Overall, 121 (88.9%) renal tumours were malignant, and 15 (11%) benign. Among malignant tumours, renal cell carcinoma (RCC) was predominant (100/121; 82.6%). The subtypes of RCC included: clear cell RCC, 84 (84%); papillary RCC, 11 (11%), chromophobe RCC, 3 (3%) and sarcomatoid RCC, 2 (2%). Other malignant tumours included: transitional cell carcinoma (9/121; 7.4%), primitive neuroectodermal tumour (5/121; 4.1%), synovial sarcoma (2/121; 1.6%), Non-Hodgkin's lymphoma (2/121; 1.6%), leiomyosarcoma (1/121; 0.8%), malignant fibrous histiocytoma (1/121; 0.8%) and squamous cell carcinoma (1/121; 0.8%). Among benign tumours, there were 11 cases of angiomyolipoma (11/15; 73.3%), three cases of oncocytoma (3/15; 20%) and one case of schwannoma (1/15; 6.6%). Almost two-third (62.7%) patients had stage I/II tumours, 22 (18.1%) stage III and 23 (19%) stage IV disease at the time of surgery.

CONCLUSION

A wide variety of renal tumours is documented in young adults with large size of the tumours and late presentation in our population.

TFE3 Translocation-Associated Renal Cell Carcinoma Presenting as Avascular Necrosis of the Femur in a 19-Year-Old Patient: Case Report and Review of the Literature

In the United States, renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90–95% of all neoplasms arising from the kidney. According to the National Cancer Institute, 58 240 new cases and 13 040 deaths from renal cancer will occur in 2010. RCC usually occurs in older adults between the ages of 50 and 70 and is rare in young adults and children. We describe a case of a TFE3 translocation-associated RCC in a 19-year-old patient presenting as avascular necrosis of the femur. Due to the rarity of this malignancy, we present this case including a review of the existing literature relative to diagnosis and treatment.

Systemic therapies for metastatic renal cell carcinoma in older adults

The introduction of targeted therapies has radically changed the treatment paradigm for metastatic renal cell carcinoma (mRCC). However, multiple clinical dilemmas have emerged. For instance, limited data are available to juxtapose the safety and efficacy profile of targeted therapies between older and younger adults. Herein, pivotal trials of vascular endothelial growth factor (VEGF)- and mammalian target of rapamycin (mTOR)-directed therapies are assessed in the context of their implications in treating older adults with mRCC. In general, subset analyses from these pivotal studies suggest similar efficacy of targeted therapies amongst older adults. Aging is accompanied by a multitude of physiological changes, as well as an increased prevalence of co-morbidities. The age-related toxicity profiles of targeted agents for mRCC are detailed to provide a framework for the risks and benefits of these therapies in older adults. Ultimately, tools such as the Comprehensive Geriatric Assessment (CGA) that account for physiological (as opposed to chronological) age may prove useful in the evaluation and treatment of older adults with mRCC.

Renal cell carcinoma with novel VCL-ALK fusion: new representative of ALK-associated tumor spectrum

Renal cell carcinoma represents a model for contemporary classification of solid tumors; however, unusual and unclassifiable cases exist and are not rare in children and young adults. The anaplastic lymphoma kinase (ALK) gene has recently been implicated in subsets of pulmonary, esophageal, breast, and colon cancers. These findings strengthen the importance of molecular classification of carcinomas across different organ sites, especially considering the evolving targeted anticancer therapies with ALK inhibitors. In the current study of six pediatric renal cell carcinomas, two cases exhibited structural karyotypic abnormalities involving the ALK locus on chromosomal band 2p23. Fluorescence in situ hybridization (FISH) studies were positive for an ALK rearrangement in one case, and subsequent 5' rapid amplification of cDNA ends analysis of this tumor revealed that the 3' portion of the ALK transcript encoding for the kinase domain was fused in frame to the 5' portion of vinculin (VCL, NM_003373). The new fusion gene is predicted to have an open reading frame of 4122 bp encoding for a 1374-aa oncoprotein; its expression was shown by immunoblotting with anti-VCL and anti-ALK antibodies in tumor tissue lysates. Immunohistochemistry with the same antibodies demonstrated cytoplasmic and subplasmalemmal localization of the oncoprotein determined by its N-terminal VCL portion. FISH with a custom-designed VCL-ALK dual-fusion probe set confirmed the presence of the fusion in neoplastic cells and demonstrated the potential clinical utility of this approach for detecting VCL-ALK in routinely processed tissue. The five remaining pediatric renal cell carcinomas did not show ALK rearrangement by FISH or ALK expression by immunohistochemistry. The data identify the kidney as a new organ site for ALK-associated carcinomas and VCL as a novel ALK fusion partner. The results should prompt further studies to advance the molecular classification of renal cell carcinoma and help to select patients who would benefit from appropriate targeted therapies.

Pediatric renal cell carcinoma

Renal cell carcinoma (RCC) comprises about 5% of pediatric renal neoplasms. It has been recognized as a second malignancy in multiple reports. It is generally symptomatic at diagnosis, and most children with RCC present with more locally advanced disease than do adults. Contemporary investigation of pediatric RCC has demonstrated that a large percentage of these tumors bear cytogenetic translocations involving the MiT family of transcription factors. Surgical therapy for these children resembles operative intervention for adult RCC, though debate continues about the precise role of lymph node dissection. There are no adequately powered studies to support conclusions about adjuvant or neoadjuvant chemotherapy for children with RCC. This may be ameliorated by a multi-institutional protocol which is enrolling patients.

Renal cell carcinoma in the pediatric population: Results from the California Cancer Registry

BACKGROUND

Renal cell carcinoma (RCC) is a rare disease in children and adolescents. This study aimed to review epidemiologic characteristics and survival for pediatric RCC patients using a large, population-based database.

PROCEDURE

The California Cancer Registry (CCR) was reviewed from 1988 to 2004. All cases of RCC in patients younger than 21 years were identified and annual age-adjusted incidence rates were determined for the overall population and subdivided by ethnicity. Tumors were classified by stage and grade, and actuarial mortality rates were calculated.

RESULTS

From 1988 to 2004, 43 cases of RCC were identified in patients younger than 21 years, accounting for 4.3% of all renal tumors in this age group. The overall annual age-adjusted incidence was 0.01/100,000 with the tumor more common in non-Hispanic blacks (0.03/100,000) compared to non-Hispanic whites (0.01/100,000), Hispanics (<0.01/100,000), and non-Hispanic Asians/Pacific Islanders (<0.01/100,000). The mean age at presentation was 15.4 years (SD 4.03, SE 0.615). RCC was identified more frequently in females (58.14%). At the time of presentation, 53.49% of tumors were localized, 20.93% were regionally advanced, and 25.58% were metastatic. The observed actuarial survival at 5 and 10 years was 61% (+/-15.7%).

CONCLUSION

Pediatric RCC is an uncommon and aggressive tumor that occurs most frequently in children in the second decade of life, more often in females and blacks. The epidemiological characteristics of this tumor differ from adult RCC and Wilms tumor, suggesting its distinctive biology and potential need for alternative treatment strategies.

Renal translocation carcinomas: clinicopathologic, immunohistochemical, and gene expression profiling analysis of 31 cases with a review of the literature

We report clinicopathologic features of a large series of renal translocation carcinomas from a multicentric study. Diagnosis was performed by cytogenetic examination of fresh material and/or by immunochemistry with antibodies directed against the C-terminal part of transcription factor E3 (TFE3) and native transcription factor EB (TFEB) proteins. Clinical data, follow-up, and histologic features were assessed. Antibodies against CK7, CD10, vimentin, epithelial membrane antigen, AE1-AE3, E-cadherin, alpha-methylacyl-coenzyme A racemase, melan A, and HMB45 were tested on tissue microarrays. Whole-genome microarray expression profiling was performed on 4 tumors. Twenty-nine cases were diagnosed as TFE3 and 2 as TFEB renal translocation carcinomas, including 13 males and 18 females, mean age 24.6 years. Two patients had a previous history of chemotherapy and 1 had a history of renal failure. Mean size of the tumor was 6.9 cm. Thirteen cases were > or = pT3 stage. Twelve cases were N+ or M+. Mean follow-up was 29.5 months. Three patients presented metastases and 5 have died. Mixed papillary and nested patterns with clear and/or eosinophilic cells represented the most consistent histologic appearance, with common foci of calcifications regardless of the type of translocation. Using a 30 mn incubation at room temperature, TFE3 immunostainings were positive in only 82% of our TFE3 translocation carcinomas. Both TFE3 and TFEB renal translocation carcinomas expressed CD10 and alpha-methylacyl-coenzyme A racemase in all cases. An expression of E-cadherin was observed in two-third of cases. Cytokeratins were expressed in less than one-third of cases. Melanocytic markers were expressed at least weakly in all cases except two. Unsupervised clustering on the basis of the gene expression profiling indicated a distinct subgroup of tumors. TRIM 63 glutathione S-transferase A1 and alanyl aminopeptidase are the main differentially expressed genes for this group of tumors. Our results suggest that these differentially expressed genes may serve as novel diagnostic or prognostic markers.

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

BACKGROUND

Pediatric renal cell carcinoma (RCC) is clinically distinct from adult RCC. Characterization of the unique biological and clinical features of pediatric RCC are required.

METHODS

A retrospective review and biological analysis of all RCC cases presenting to Cincinnati Children's Hospital Medical Center (CCHMC) in the last 30 years was undertaken. Cases were classified according to the recent World Heath Organization morphologic classification and according to TFE3/TFEB status. A literature review of pediatric TFE+ cases was performed.

RESULTS

Eleven cases of RCC with clinical data were identified in our institutional review as follows: 6 clear cell, 2 papillary, 2 translocation, and 1 sarcomatoid. Upon reanalysis, 1 papillary and 1 sarcomatoid were confirmed, 1 case was "unclassified", and 8 of 11 (72.7%) had features consistent with translocation morphology. Of these 8, all demonstrated immunoreactivity for TFE3 (7 patients) or TFEB (1 patient) protein. In 3 cases, cytogenetics was available, each demonstrating confirmatory MiTF/TFE translocations. Seven of 8 TFE+ RCC patients presented with TNM Stage III/IV disease. Literature analysis confirmed a significant increase in advanced stage presentation in pediatric TFE+ RCC compared with TFE- RCC. Fourteen of fifteen (93.3%) patients with TFE+ stage III/IV RCC due to lymph node spread (N+ M(0)) remain disease free with a median and mean follow-up of 4.4 and 6.3 years, respectively (range, 0.3-15.5).

CONCLUSIONS

Translocation morphology RCC is the predominant form of pediatric RCC, associated with an advanced stage at presentation. Patients with TFE+ N+ M(0) RCC maintain a favorable short-term prognosis after surgery alone. Young RCC patients should be screened for translocation morphology, and the screening information should be considered when debating adjuvant therapy.

Renal tumours of childhood: an update

The role of the pathologist has been fundamental in the progress of the treatment of paediatric renal tumours. There are different philosophies in the treatment of these tumours, and there have been many recent advances in the areas of chemotherapy, identification of new entities, prognostic histological criteria following treatment and molecular prognostic and diagnostic features. This review discusses the different approaches of the different treatment protocols from Europe and North America, and reviews staging criteria, prognostic criteria and also the different tumour entities.

[Sporadic kidney cancer in patients younger than 45]

INTRODUCTION

The incidence of kidney cancer is constantly increasing. The objective of this study was to report the characteristics of sporadic kidney tumours observed in a population of patients under the age of 45 years and to define prognostic factors based on a 5-year follow-up.

MATERIAL AND METHODS

Between 1985 and 2003, 64 patients, with a mean age of 38 +/- 7 years, presenting with sporadic kidney cancer were included in this retrospective study.

RESULTS

Sporadic kidney cancer was discovered incidentally in 39.1% of young adults, predominantly in women. Radical nephrectomy was performed in 57 cases and partial nephrectomy was performed in 5 cases. The distribution by histological type was comparable to that of the general population, but pathological examination of carcinomas showed a high Führman grade in 66% of cases. The mean follow-up was 72 59 months. The 3-year and 5-year overall survival was 79% and 76.7% respectively. The mortality rate was 25%: 13 specific deaths and 3 nonspecific deaths. TNM stage was a prognostic factor on univariate and multivariate analysis. The mode of discovery and the ASA score were also identified as prognostic factors on univariate analysis.

CONCLUSION

Sporadic kidney cancer is rare in adults before the age of 45 years and presents with symptoms. Earlier detection would allow an improvement of the prognosis.

[Pediatric renal cell carcinoma. A rare differential diagnosis of Wilms' tumor]

Renal cell carcinoma (RCC) is a very rare pediatric disease and should be treated as an entity of its own because of differences in symptoms, therapy, and prognosis from the adult form of the disease. Our objective is to discuss the difficulties in clinical diagnosis, prognosis, and therapy of this very rare disease in children and to provide a review of the current literature.

Pediatric Renal Cell Carcinoma Associated With Xp11.2 Translocation/TFE3 Gene Fusion

Renal cell carcinoma (RCC) in children and young adults is rare and pathologically problematic. RCC can be either hereditary or sporadic and has a guarded prognosis because appropriate management has not been established. A case of RCC in an 11-year-old is reported. The clinical presentation was a right abdominal mass, hematuria, urinary tract infection, and wasting. Radio-logically, the mass was found within the right kidney with calcification and paraaortic lymphadenopathy. The postsurgical diagnosis was Wilms' tumor stage T4N2M0. On gross inspection, the tumor was ill defined, extending across Gerota's fascia and into the ureter lumina. Microscopically, the tumor consisted of malignant epithelial cells with clear and eosinophilic cytoplasm in nested, papillary, and alveolar configuration. Hyaline nodules, psammoma bodies, vascular invasion, capsular invasion, and extension into the ureter were also found. Immunohistochemically, the cells showed strong nuclear immunoreactivity for TFE3. We concluded that this case was an RCC associated with Xp11.2 translocation/ TFE3 fusion, Fuhrman grade 3, stage IV.

[Incidental renal cancer in young adults: clinical and histopathological findings]

OBJECTIVE

to evaluate the clinical and pathological renal cancer (CR) characteristics in our series of tumours, analyzing its impact in the group of age less than 40 years.

MATERIAL AND METHODS

We studied 294 patients with CR. The pathologic characteristics were analyzed and DNA ploidy pattern of the surgical pieces were done in 252 patients. The patients were divided in two groups based on age, greater or less to 40 years, well then clinical and pathologic characteristics were compared between.

RESULTS

Of all patients, 26 of 294 patients (8,94%) were included in the young age group (less to 40 years). We did not found differences between both groups comparing stage, tumoral volume, treatment realized or DNA ploidy pattern, but in nuclear grade with more aggressive tumours in young people (p=0,0018), without differences in recurrence-free survival or actuarial disease specific survival rate.

CONCLUSIONS

The findings in our study indicate that the natural history and outcome of the RC is similar in both older and younger patients. Therefore, in our opinion, the management of CR in young people should be established with independence of the age.

Part I: Primary malignant non-Wilms' renal tumours in children

Non-Wilms' tumours form a small heterogeneous group of clinically significant renal malignancies in children, including renal-cell carcinoma, clear-cell sarcoma, (congenital) mesoblastic nephroma, rhabdoid tumour, and renal medullary carcinoma. Good progress has been made in the assessment of these tumours, which has led to a greater understanding of the molecular changes that occur in their development. This review is the first of two parts, and provides an updated review of the clinical presentation, imaging, and pathology of these tumours.

Chromophobe renal cell carcinoma in a child: case report and review of the literature

Renal cell carcinomas are rare in children but are in the differential diagnosis of renal masses in children age 5 years and older. We present a case of a chromophobe renal cell carcinoma in an 8-year-old boy that arose as a 7-cm (greatest dimension) unilateral renal mass. The tumor had eosinophilic cells, with the typical perinuclear halos and positive staining with Hale's colloidal iron that are seen in this tumor. Although papillary renal cell carcinomas are the most common variant of renal cell carcinoma in children, chromophobe renal cell carcinoma is a rarely reported variant that is not uncommon and has a relatively favorable prognosis in adults.

Population-based study of renal cell carcinoma in children in Germany, 1980-2005: more frequently localized tumors and underlying disorders compared with adult counterparts

BACKGROUND

Childhood renal cell carcinomas (RCCs) differ histologically and biologically from their adult counterparts. The characteristics of RCC-affected children and their tumors, the influence of treatment, and outcome have so far not been studied in a nonselected, population-based cohort.

METHODS

A retrospective analysis was undertaken of RCC patients less than 16 years old reported to the German Childhood Cancer Registry and to the Kiel Paediatric Tumor Registry from 1980 to 2005.

RESULTS

Forty-nine RCC in children (24 boys, 25 girls) with a median age of 10.6 years were identified. In about every third child possibly RCC-related underlying disorders (tuberous sclerosis, neuroblastoma, teratoma with chemotherapy, Saethre-Chotzen syndrome, chronic renal failure) or related diseases in their family were found. The pathologic subtypes were papillary in 16 (33%), translocation type in 11 (22%), unclassified in 8 (16%), and rarely clear-cell (n = 3) or others. Thirty-four (69%) patients had localized RCC, 8 (16%) patients regional lymph node metastases, and 4 (8%) patients distant metastases. Event-free survival and overall survival rates at 5 years were 96% for localized RCC, 69% and 75% for regional lymph node-positive, 25% and 33% for distant metastatic RCC, respectively. Two of 4 patients with distant metastases received immunotherapy combined with chemotherapy and surgery, both are alive, 1 of them disease-free for 6.9 years.

CONCLUSIONS

Pediatric RCCs are predominantly localized diseases. Children with RCC frequently suffer underlying disorders. Survival rates in localized and regional lymph node-positive cases are favorable. Because of the rarity of RCC in childhood, an international study is necessary.

Association between age and clinical characteristics of renal cell carcinoma in adult patients

AIM

To study the association between age and clinical characteristics of renal cell carcinoma in adult patients.

METHODS

Three hundred and ten patients with renal cell carcinoma were classified into three groups: <or=40 years group, 41-59 years group and >or=60 years group. The clinical characteristics of the three groups were compared to define the association.

RESULTS

The male/female ratio was 1.3/1, 2.0/1, 3.3/1 in the three groups, respectively, and a significant difference appeared when comparing the <or=40 years group to the >or=60 years group (P=0.010). The respective percentage of incidental renal cell carcinoma was 27.9%, 43.2%, 31.2%, and it was significantly higher in the 41-59 years group than the >or=60 years group (P=0.047). The incidence of poorly differentiated renal cell carcinoma decreased with age increasing (11.6% vs 5.2% vs 2.7%), and there was significant difference between the <or=40 years group and the >or=60 years group (P=0.038). In the <or=40 years group, the incidence of lymph node metastasis was 18.6%, which was significantly higher than the other two groups (P<0.05). The percentage of T3a tumors was lower in <or=40 years group and the percentage of T1-3aN0M0 tumors was significantly higher in the 41-59 years group.

CONCLUSIONS

The percentage of female patients decreases with increasing age. The higher percentage of incidental renal cell carcinoma leads to the higher percentage of T1-3aN0M0 tumors in middle-aged patients. The higher percentage of poorly differentiated renal cell carcinoma led to the higher incidence of lymph node metastasis and decreased percentage of T3aN0M0 tumors in younger patients.

PRCC-TFE3 renal cell carcinoma in a boy with a history of contralateral mesoblastic nephroma

The genetics of renal tumors in children is widely recognized. However, most of the studies published to date emphasize the association between Wilms tumor and the WT-1 gene. Recently, a unique translocation between the X chromosome and chromosome 1 or t(X;1) has been described in several reports of renal cell carcinomas (RCCs) diagnosed in children and adolescents that results in PRCC-TFE3 gene fusion. We report here a 9-year old African-American boy with a history of a right congenital mesoblastic nephroma treated with nephrectomy and followed by annual checkups. After 9 years, he was diagnosed with a mass at the hilum of the left kidney during the work-up of new-onset hypertension. A limited biopsy revealed densely hyalinized connective tissue that was initially interpreted to be a hyalinized contralateral mesoblastic nephroma. The child received chemotherapy, but the mass continued to grow. He underwent a left nephrectomy, and the pathology was diagnostic for a clear cell RCC. Chromosomal analysis disclosed a t(X;1)(p11.2;q21) translocation, which is known to result in a PRCC-TFE3 gene fusion. The tumor showed nuclear labeling for TFE3 protein by immunohistochemistry, supporting the above diagnosis. He has been on hemodialysis, is tumor free, and has not been receiving chemotherapy for 24 months. This is the first report of a RCC as a second malignant neoplasm in a child treated for a congenital mesoblastic nephroma.

Pediatric renal cell carcinoma: clinical, pathologic, and molecular abnormalities associated with the members of the mit transcription factor family

We describe the clinical features, outcome, pathology, cytogenetics, and molecular aspects of 13 pediatric papillary renal cell carcinomas during a 19-year period. Seven cases (54%) had translocations involving Xp11.2 (TFE3). They were identified by cytogenetic, molecular, and/or immunohistochemical analyses. All Xp11.2+ translocations were TFE3+ by immunostaining. Cytogenetic and/or polymerase chain reaction analyses identified 3 cases with t(X17) and 1 case with t(1;17), and all had additional translocations. Histologic features in common in TFE3+ tumors also were present in some TFE3- tumors. One TFE3- tumor had complex cytogenetic abnormalities, 55XY,+2,del(3)(p14),+7,+8,+12,+13,+16,+17,+20[11 ], and 2 cases had normal karyotypes. None had t(6;11)/TFEB+ immunostaining. Five cases had focal, weak MITF tumor immunostaining. The key clinical findings were as follows: (1) The presence of an Xp11.2 (TFE3) translocation frequently is associated with advanced stage at initial examination. (2) All patients who underwent complete, partial nephrectomy with clear margins (adequate only for stage 1) and resection of metastases were alive and relapse-free at last follow-up. (3) The mean +/- SD event-free survival and overall survival rates at 5 years were both 92% +/- 7.4%. (4) One patients with a TFE3+ and MITF+ tumor and 66-87,XXY,der(1)t(1;8)del(4)(q?) der(11)t(11;15)der17t(X;17 abnormalities died 9 months after diagnosis.

[Renal cancer in elderly: clinical and histopathological findings]

OBJECTIVE

to evaluate the clinical and pathological characteristics of the CCR in our series of tumors, analyzing its impact in the group of age greater than 65 years.

MATERIAL AND METHODS

300 patients with renal adenocarcinoma (CCR) were studied. In 252, ploidy pattern of DNA and pathologic characteristics of the surgical pieces were done. According to the criteria of the Spanish Society of Geriatrics, the patients were divided in two groups based on the age, greater and smaller of 65 years. The clinical and pathologic characteristics were compared between both groups.

RESULTS

103 of the 300 patients (33.3%) were included in the geriatric group. We did not found differences between both groups comparing stage, tumoral volume or treatment realized, but found differences in DNA ploidy pattern, recurrences and survey.

CONCLUSIONS

The RCC in the elderly has a few clinical and pathological characteristics similar to the rest of patients in our series. Nevertheless differences exist in the average and actuarial survival, which is minor in the patient of more than 65 years, cause the percentage of detected aneuploidies and number of recurrences in not confined tumors in this group of age.

Translocation carcinomas of the kidney after chemotherapy in childhood

PURPOSE

Children who survive cancer are at more than 19-fold increased risk of developing another malignancy. Renal cell carcinoma (RCC) occurring as a secondary malignancy is uncommon. Translocation RCC, bearing TFE3 or TFEB gene fusions, are recently recognized entities for which risk factors have not been identified.

PATIENTS AND METHODS

We describe the clinical, pathologic, cytogenetic, and molecular data on six translocation RCCs that arose in five young patients who had received chemotherapy.

RESULTS

The ages at time of diagnosis of the RCC ranged from 6 to 22 years. Histologically, these tumors showed typical features previously described for translocation RCCs. At the molecular level, three tumors contained the ASPL-TFE3 fusion, two contained Alpha-TFEB, and one contained PRCC-TFE3. The intervals between chemotherapy and the diagnosis of RCC ranged from 4 to 13 years. The indications for the antecedent chemotherapy were varied and included acute promyelocytic leukemia, acute myeloid leukemia with t(9;11), bilateral Wilms' tumor, systemic lupus erythematosus, and conditioning regimen of bone marrow transplant for Hurler's syndrome. Only the latter patient had also received radiation. Hence, among 39 genetically confirmed translocation RCCs in our personal experience, six (15%) have arisen in patients who had received cytotoxic chemotherapy.

CONCLUSION

Cytotoxic chemotherapy may predispose to the development of renal translocation carcinomas.

Aplicación clínica de las actuales clasificaciones del cáncer renal

The purpose of classifying neoplasias is to recognize groups with similar progress and prognosis and, if possible, receiving the same treatment. This is why those classifications are systematically being submitted to review and improvement through the new technologies. Differentiation of various entities in renal cancer has been comparatively fast, as the new genetic and molecular discoveries have confirmed the morphologic criteria of the different cell types, thus making it possible to open new therapeutic pathways. Using the current WHO classification we recognize subtypes with excellent prognosis (Multilocular cystic renal carcinoma, Type I renal papillary carcinoma, Tubular and fusocellular mucinous carcinoma), other very aggressive ones (Bellini's collecting duct carcinoma, Medullary carcinoma), and also that the sarcomatoid transformation, even in small areas, impacts the prognosis negatively. Childhood-characteristic renal carcinomas associated with chromosome translocations have been recognized (genetic fusion TFE3 or TFEB), as well as the family forms of renal carcinoma. Regarding the UICC (International Union Against Cancer) classification, there are a series of aspects under argument (size, venous invasion, microvascular invasion, invasion of the adipous tissue of the renal sinus) that shall be discussed too, since it is possible that some modifications of the TNM might occur in the near future.

Adult Papillary Renal Tumor With Oncocytic Cells

We report a series of 10 oncocytic renal papillary tumors, with the aim of determining their clinicopathologic features. All patients were male (median age, 71 years), treated by radical nephrectomy and free of recurrence or metastasis (median follow-up, 62 months). Tumors (median size, 3.3 cm) were intrarenal and well limited, with no extrarenal extension. They consisted of thin, nonfibrotic papillae lined by a single layer of oncocytic cells, with finely granular eosinophilic cytoplasm and round regular nucleus exhibiting central nucleolus (Fuhrman grade II, except for one grade III). Foci of necrosis were present in most cases. All tumors were immunoreactive for alpha-methylacyl-coenzyme A racemase, vimentin, and CD10; 4 expressed renal cell carcinoma antigen and 3 cytokeratin 7. There were a low number of cytogenetic changes in the 5 analyzed cases (median, 4; range, 1-7), with no trisomy 7 or 17. Papillary architecture, necrosis, and immunohistochemical profiles argued against the diagnosis of oncocytoma and suggested our cases to be part of the papillary renal cell carcinoma group. However, the cases were atypical for type 1 papillary carcinoma (due to oncocytic cells and absence of trisomy 17) and for type 2 (due to a good outcome). These results suggest that adult papillary renal tumors with oncocytic cells might be a distinct variant in the papillary renal cell carcinoma group.

The spectrum of pediatric tumors in infancy, childhood, and adolescence: a comprehensive review with emphasis on special techniques in diagnosis

The spectrum of pediatric tumors varies considerably, from those derived from blastemal cells in various organ systems to proliferations of soft tissue supporting cells to hamartomatous processes that mimic malignant tumors. Small round cell tumors are often undifferentiated or poorly differentiated, making it difficult sometimes to provide a definitive diagnosis. Both benign and malignant tumors require a coordinated method for diagnosis, and need a comprehensive evaluation to provide the most appropriate diagnosis for designing therapy and predicting prognosis. Pediatric tumors require the integration of routine histopathologic examination with histochemical, immunocytochemical, ultrastructural, cytogenetic, and diagnostic molecular pathology techniques. This review provides updated guidelines with respect to the application of these special techniques in this rapidly evolving diagnostic arena.

Translocation carcinomas of the kidney

A significant proportion of RCCs of children and young adults bear specific chromosome translocations that result in gene fusions that involve members of the MiTF/TFE transcription factor family. These include the Xp11-translocation carcinomas, which bear TFE3 gene fusions, and the renal carcinomas with the t(6;11)(p21;q12), which bear an Alpha-TFEB gene fusion. Both types of translocation result in overexpression of the fusion gene products, such that nuclear labeling for TFE3 or TFEB by immunohistochemistry is a sensitive and specific marker of these respective tumor types. The clinical behavior of these neoplasms relative to conventional, adult-type renal carcinomas remains to be determined, and will be an important area of future investigation.

COMPARISON OF PRESENTATION AND OUTCOME FOR PATIENTS 18 TO 40 AND 60 TO 70 YEARS OLD WITH SOLID RENAL MASSES

PURPOSE

We compared histological subtype, pathological features and outcome of patients with solid renal masses who were 18 to 40 years old vs patients who were 60 to 70 years old.

MATERIALS AND METHODS

We conducted a retrospective review of the Mayo Clinic Nephrectomy Registry from 1970 to 2000, and identified 124 patients 18 to 40 years old and 1,067 patients 60 to 70 years old available for analysis.

RESULTS

There was no significant difference in the incidence of benign solid renal masses between patients 18 to 40 years old and those 60 to 70 years old (13.7% vs 10.2%). Among patients with renal cell carcinoma (RCC), younger patients were more likely to have chromophobe RCC (13.1% vs 3.6%) and less likely to have clear cell RCC (70.1% vs 81.5%) than older patients. Among patients with clear cell RCC, younger patients were more likely to have stage pT2b or lower tumors (82.7% vs 69.9%) and a higher incidence of cystic clear cell RCC (10.7% vs 2.2%) than older patients. Younger patients had an improved cancer specific survival compared with older patients but this difference was not statistically significant (risk ratio 0.71, p =0.127).

CONCLUSIONS

We found that patients 18 to 40 years old were more likely to have chromophobe and less likely to have clear cell RCC compared with patients 60 to 70 years old. We did not identify a higher incidence of papillary RCC in younger patients. Patients with clear cell RCC 18 to 40 years old had a higher incidence of low stage and cystic tumors compared with patients 60 to 70 years old, features which have been shown to have a favorable prognosis. These factors likely contributed to improved cancer specific survival for younger patients.

[Kidney tumors in childhood]

Types of renal tumors arising in children are different from those occurring in adults. Nephroblastoma is the most common (85%) with a clinical outcome which has dramatically improved in the last 30 years. Current classifications are aimed at better adaptation of treatment to each individual case, reducing iatrogenic complications without impairing total cure. Amongst entities which have been recently described or are better known we can find juvenile carcinoma associated with Xp11.2 translocation, renal medullary carcinoma, metanephric tumors, etc. Role of molecular cytogenetics is increasing for classification (and treatment) and this should always be kept in mind when dealing a fresh specimen of childhood renal tumor.