Pediatric non-Wilms' renal tumors: a third world experience

Case report of an infant with congenital mesoblastic nephroma leading to pulmonary metastasis

Congenital mesoblastic nephroma is considered a tumour with favourable clinical behaviour with only few reported cases of metastases. We report an infant who underwent complete resection and later developed pulmonary metastasis. Ten-month-old baby girl initially presented at 3 weeks of age with macroscopic haematuria, hypertension and a lumbar mass. Contrast-enhanced computed tomography revealed a tumour arising from the left kidney without local invasion or metastasis. She underwent left nephrectomy. Immunohistochemistry confirmed a cellular type of congenital mesoblastic nephroma. At 10 months, she presented with difficulty in breathing. Contrast-enhanced computed tomography revealed an opacity in the right hemi-thorax. Histology of lung mass was suggestive of deposits from the previously excised mesoblastic nephroma. She developed a right-sided haemothorax and succumbed. This case report highlights the fact that even though congenital mesoblastic nephromas are considered tumours with favourable clinical behaviour, they can present later with distant metastasis. Therefore, clinicians need to be aware of this rare malignant potential and adhere to meticulous follow-up protocols.

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.

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.

Epidemiologic and Clinical Outcomes of Pediatric Renal Tumors in Korea: A Retrospective Analysis of The Korean Pediatric Hematology and Oncology Group (KPHOG) Data

PURPOSE

Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea.

MATERIALS AND METHODS

From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed.

RESULTS

Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001).

CONCLUSION

The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Non-Wilms' renal tumors in children: experience with 139 cases treated at a single center

Background

Pediatric non-Wilms renal tumors (NWRTs), which comprise a small proportion of renal tumors, are a heterogeneous group of neoplasms with variable malignant potential, mortality, and response to treatment. We performed this study to determine the clinical characteristics, management and prognosis of children with Pediatric NWRTs.

Methods

Medical records of all patients (n = 139) treated for NWRTs over a 12-year period (2008.01–2019.10) at a single center were reviewed retrospectively.

Results

The histopathological groups of NWRTs included malignant rhabdoid tumor of the kidney (MRTK) (n: 30, 21.6%), renal cell cancer (RCC) (n: 26,18.7%), clear cell sarcoma of the kidney (CCSK) (n: 24,17.3%), congenital mesoblastic nephroma (CMN) (n: 21,15.1%), cystic nephroma (CN) (n: 16,11.5%), metanephric tumors (n: 12, 8.6%), renal angiomyoliporma (RAML) (n: 3, 2.2%), renal primitive neuroectodermal tumor (n: 2, 1.4%), renal hemangioma (n: 2, 1.4%), inflammatory myofibroblastic tumor (n: 2, 1.4%), ossifying renal tumor of infancy (ORTI) (n: 1, 0.7%). The distribution of all malignant NWRTs, including MRTK, CCSK, RCC and PNET, according to stage was as follows: stages I (n = 26), II (n = 16), III (n = 29), and IV (n = 11). The summary table shows the treatment offered to children with NWRTs. A total of 123 children were followed up for an average of 42 months. Sixteen children were lost to follow-up. Tumor-free survival was observed in 94 children. One patient who suffered from RCC is currently receiving targeted therapy and survives with the tumor. Twenty-eight children (22.8%) died.

Conclusions

Pediatric NWRTs comprise 19.1% of all renal tumors in our single center. Most NWRTs can readily be distinguished using a range of immunohistochemical markers. Molecular genetic profiling has allowed much progress in the understanding of this group of tumors, making diagnosis and classification less difficult. The mainstay treatment of malignant NWRTs, including MRTK, CCSK, RCC and PNET, is comprehensive treatment. The mainstay treatment of benign NWRTs, including RAML, CN, ORTI, CMN, metanephric tumors, and renal hemangioma, is surgical resection alone and when the tumor diameter is smaller than 7 cm and the tumor locates in one pole, NSS can be performed.

Incidence patterns of childhood non-Wilms renal tumors: Comparing data of the Nationwide Registry of Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST), Greece, and the Surveillance, Epidemiology, and End Results Program (SEER), USA

BACKGROUND

We used, for the first time, data registered in the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST)-Greece to estimate incidence/time trends of the rare childhood (0-14 years) non-Wilms tumors (non-WT), and compared the results of malignant non-WT to those from the Surveillance, Epidemiology, and End Results Program (SEER)-USA.

METHODS

Fifty-five cases (n = 33 malignant-only) were extracted from NARECHEM-ST (2001-2020) and 332 malignant cases from SEER (1990-2017). To allow between-country comparisons, age-standardized incidence rates (AIR) of malignant-only non-WT were calculated, and temporal trends were evaluated using Poisson and joinpoint regressions.

RESULTS

In NARECHEM-ST, malignant and non-malignant non-WT accounted for 22.6% of all renal tumors. Among malignant tumors, the AIR was 1.0/106 children in Greece, similar to that calculated for SEER, USA (AIR=0.9/106). The proportion of infant malignant and non-malignant non-WT was 27% (20% before 6 months) in NARECHEM-ST. Most common non-WT in Greece were congenital mesoblastic nephromas (CMN) diagnosed mainly in infancy (CIR=7.2/106). The proportion of infant malignant non-WT was 20% in SEER (AIRinfancy=2.5/106), mainly attributed to rhabdoid tumors (CIR=1.6/106). The male-to-female (M:F) ratio of malignant non-WT was 0.9 in NARECHEM-ST vs. 1.2 in SEER, whereas boys outnumbered girls with clear cell sarcoma in NARECHEM-ST (M:F=4.0). Lastly, significantly increasing trends in incidence rates were noted in NARECHEM-ST [+ 6.8%, 95% confidence intervals (CI): 0.5, 13.3] and in SEER (+7.3%, 95%CI: 5.6, 9.0).

CONCLUSIONS

Observed incidence, time trends and sociodemographic variations of non-WT may reflect differential registration practices and healthcare delivery patterns including differences regarding surveillance, coding and treatment practices.

Imaging features and differences among the three primary malignant non-Wilms tumors in children

Background

The pathology, treatment and prognosis of malignant non-Wilms tumors (NWTs) are different, so it is necessary to differentiate these types of tumors. The purpose of this study was to review the clinical and imaging features of malignant NWTs and features of tumor metastasis.

Methods

We retrospectively analyzed the CT images of 65 pediatric patients with NWTs from March 2008 to July 2020, mainly including clear cell sarcoma of the kidney (CCSK), malignant rhabdomyoma tumor of the kidney (MRTK) and renal cell carcinoma (RCC). Available pretreatment contrast-enhanced abdominal CT examinations were reviewed. The clinical features of the patients, imaging findings of the primary mass, and locoregional metastasis patterns were evaluated in correlation with pathological and surgical findings.

Results

The study included CCSK (22 cases), MRTK (27 cases) and RCC (16 cases). There were no significant differences observed among the sex ratios of CCSK, MRTK and RCC (all P > 0.05). Among the three tumors, the onset age of MRTK patients was the smallest, while that of RCC patients was the largest (all P < 0.05). The tumor diameter of CCSK was larger than that of MRTK and RCC (all P < 0.001). For hemorrhage and necrosis, the proportion of MRTK patients was larger than that of the other two tumors (P = 0.017). For calcification in tumors, the proportion of calcification in RCC was highest (P = 0.009). Only MRTK showed subcapsular fluid (P < 0.001). In the arterial phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P = 0.007), and the proportion of marked enhancement was the highest (P = 0.002). In the venous phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P < 0.001). Only CCSK had bone metastasis. There was no liver and lung metastasis in RCC.

Conclusions

NWTs have their own imaging and clinical manifestations. CCSK can cause vertebral metastasis, MRTK can cause subcapsular effusion, and RCC tumor density is usually high and calcification. These diagnostic points can play a role in clinical diagnosis.

Clinical and Molecular Characteristics and Outcome of Cystic Partially Differentiated Nephroblastoma and Cystic Nephroma: A Narrative Review of the Literature

Simple Summary

Although renal tumors in children are mostly solid masses, cystic renal tumors also occur. The most likely diagnoses for cystic renal tumors include cystic partially differentiated nephroblastoma and cystic nephroma. Since these tumors are rare, limited information on the treatment, clinical and molecular characteristics, and outcome is available. In this review, we aim to summarize all reported patients with cystic partially differentiated nephroblastoma and cystic nephroma. We identified 113 cystic partially differentiated nephroblastoma and 167 cystic nephroma patients. Surgery was the cornerstone of treatment for both tumor types and chemotherapy was generally not recommended. Cystic nephroma was often related to DICER1-mutations and second tumors, whereas cystic partially differentiated nephroblastoma was related to somatic hyperdiploidy, although testing was rare. The outcome for both tumors is favorable. This study provides information for treatment decisions and stresses the importance of a central review of radiology and pathology, as well as referral to a clinical geneticist.

Abstract

In children presenting with a predominantly cystic renal tumor, the most likely diagnoses include cystic partially differentiated nephroblastoma (CPDN) and cystic nephroma (CN). Both entities are rare and limited information on the clinical and molecular characteristics, treatment, and outcome is available since large cohort studies are lacking. We performed an extensive literature review, in which we identified 113 CPDN and 167 CN. The median age at presentation for CPDN and CN was 12 months (range: 3 weeks–4 years) and 16 months (prenatal diagnosis–16 years), respectively. No patients presented with metastatic disease. Bilateral disease occurred in both entities. Surgery was the main treatment for both. Two/113 CPDN patients and 26/167 CN patients had previous, concomitant, or subsequent other tumors. Unlike CPDN, CN was strongly associated with somatic (n = 27/29) and germline (n = 12/12) DICER1-mutations. Four CPDN patients and one CN patient relapsed. Death was reported in six/103 patients with CPDN and six/118 CN patients, none directly due to disease. In conclusion, children with CPDN and CN are young, do not present with metastases, and have an excellent outcome. Awareness of concomitant or subsequent tumors and genetic testing is important. International registration of cystic renal tumor cohorts is required to enable a better understanding of clinical and genetic characteristics.

Incidence, treatment, and outcomes of primary and recurrent Non-Wilms renal tumors in children: Report of 109 patients treated at a single institution

INTRODUCTION

Non-Wilms renal tumors represent a compelling subset of childhood renal tumors. However, their relative rarity renders accurate diagnosis, and therapy challenging which in some instance is inferred from their adult counterparts.

OBJECTIVE

To describe the incidence and analyze the diagnostic challenges, therapies and, outcomes of non-Wilms renal tumors at the largest tertiary cancer centre in India.

METHODS

All patients with histologically confirmed non-Wilms renal tumours diagnosed in the paediatric oncology unit of Tata Memorial Hospital between 2006 and 2019 were included. Data regarding clinical and radiological features and treatment outcomes were retrieved from the prospectively maintained institutional database. At the outset, histological types were categorised into a high and low-risk group depending on anticipated survival. Survival analysis was performed utilising the Kaplan-Meier method on SPSS software version 24.0.

RESULTS

Of the 569 patients with renal tumors, 109 (19%) patients with primary (n = 97) or recurrent (n = 12) non-Wilms renal tumors were included. Histological high-risk group included clear cell sarcoma (CCSK) (39.4%), renal cell carcinoma (RCC) (19.3%), malignant rhabdoid tumor (MRTK) (12.8%), Ewing's sarcoma (rES) (15.6%), synovial sarcoma (2%), and undifferentiated sarcoma (2%). The low-risk group comprised of congenital mesoblastic nephroma (CMN) (4.6%), cystic partially differentiated nephroblastoma (2%), and other rare tumors (3%). Diagnostic error occurred in 2 patients in the high-risk group. All low-risk tumours were treated with surgery alone and most (97%) high-risk tumors were operated either upfront (61.5%) or after preoperative chemotherapy (38.4%). Adjuvant therapy based on histology was offered to 70%. The recurrent tumors received various salvage treatments including chemotherapy; radiotherapy; surgery and immunotherapy, however, only 2 patients could be salvaged. The 3-year overall survival for the entire cohort with primary tumors was 59%, and the survival rates were 76.7%, 77.9%, 0.0%, and 52% for CCSK, RCC, MRTK, and rES (summary figure). Low-risk tumors had 100% survival while the recurrent tumors had a median survival of 10.5 months.

CONCLUSIONS

Non-Wilms renal tumors constitute a heterogeneous group of tumors, accounting for less than 20% of all renal tumors. Low-risk tumors are associated with excellent outcomes following surgery alone while the high-risk tumours have a variable outcome. MRTK and recurrent non-Wilms tumour have the worst survival. Favourable outcomes for CCSK and RCC and worst outcomes for MRTK were observed in this study. Renal ES have higher incidence of treatment failure and unsatisfactory outcomes. Recurrent non-Wilms tumours have an extremely poor outcome and more alternative or innovative approaches are needed for their treatment.

Health disparities among tennessee pediatric renal tumor patients

BACKGROUND/PURPOSE

Wilms tumor (WT) poses a cancer health disparity to black children globally, which has not been evaluated thoroughly for other pediatric renal cancers. We aimed to characterize health disparities among Tennessee children treated for any renal cancer.

METHODS

The Tennessee Cancer Registry (TCR) was queried for patients ≤18 years having any renal cancer (n = 160). To clarify treatment and outcomes, we performed a retrospective cohort study of pediatric renal cancer patients in our institutional cancer registry (ICR; n = 121). Diagnoses in both registries included WT, Sarcoma/Other, and Renal Cell Carcinoma. Wilcoxon/Pearson, Kaplan-Meier, and logistic regression were completed.

RESULTS

In both registries, WT comprised the most common renal cancer and youngest median age. Sarcoma was intermediate in frequency and age, and RCC was least common, having the oldest age (p < 0.001). In the TCR, black patients comprised 26% of all patients, presented more commonly with distant disease than white patients (37% v. 16%; p = 0.021), and showed worse overall survival (73% v. 89%; p = 0.018), while the ICR showed similar survival between race groups (92% v. 93%, p = 0.868). Sarcoma and metastases were independent predictors of death in both registries (p ≤ 0.002).

CONCLUSIONS

Black children in Tennessee presented with more advanced disease and experienced worse survival when combining all renal cancer types, particularly RCC and Sarcoma. When treated at a comprehensive pediatric cancer center, these survival disparities appear diminished.

TYPE OF STUDY

Prognostic study.

LEVEL OF EVIDENCE

Level II (retrospective cohort).

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.

Evaluation of renal tumors in children

OBJECTIVE

Renal tumors are not uncommon in children. In this study, we aimed to evaluate the clinical and pathological features of renal tumors in children.

MATERIAL AND METHODS

Between January 2008 and December 2017, the records of children with renal tumors in our institution were retrospectively analyzed. Data collected were composed of demographic and clinical characteristics including gender, age at time of diagnosis, symptoms, laterality of the tumor and pathological evaluation.

RESULTS

A total of 48 children with renal tumor (28 males and 20 females) were included in the study. They were diagnosed at mean age of 53.26±46.64 months (range: 1-192) and the mean follow-up period was 73.45±48.92 months (range: 6-120). The most common symptom was a lump or mass in the area of the kidneys (45.8%), abdominal pain and hematuria (14.6%). Four patients (8.3%) were diagnosed at antenatal period. 68.8% of the children had Wilms tumor and the major histological groups of non-Wilms renal tumors were renal cell carcinoma (12.5%), congenital mesoblastic nephroma (10.4%) and angiomyolipoma (4.2%). 10.4% of the children had bilateral tumors and one patients had Wilms tumor with horseshoe kidney. 87.5% of the children were treated with surgery and of those 7 (14.5%) underwent nephron-sparing surgery. The patients had chemotherapy and radiotherapy (83.3% and 41.7%, respectively). Seven patients (14.6%) died during follow-up.

CONCLUSION

Wilms tumor is the most common pediatric renal neoplasm. On the other hand, we showed that considerable number of children with renal tumors had non-Wilms tumors including renal cell carcinoma, congenital mesoblastic nephroma and angiomyolipoma.

Congenital mesoblastic nephroma 50 years after its recognition: A narrative review

Congenital mesoblastic nephroma (CMN) is a rare pediatric renal tumor with low malignant potential that most commonly occurs early in infancy. Treatment strategies are based on the few published CMN series, while a significant number of CMN patients have been described in case reports. The aim of this narrative review was to create an up-to-date overview of the literature. Complete surgical removal is curative in most cases. The risk of treatment-related mortality (both surgery- and chemotherapy-related) is relatively high in the first weeks of life, indicating that these young patients deserve special attention with respect to timing and type of treatment.

Genitourinary rhabdomyosarcoma: lessons from a developing-world series

OBJECTIVE

The objective was to retrospectively review a large series of pediatric patients with genitourinary rhabdomyosarcoma from a developing country.

METHODS

A total of 49 children were treated over a 47-year period (1961-2008). Analysis of the clinical presentation, demographics, surgical records, histological results, and oncological management was performed. The patients were analyzed as a whole and also in 2 separate groups (pre- and post-1992).

RESULTS

The median age at clinical presentation was 3½ years. The majority (59%) of patients were Intergroup Rhabdomyosarcoma Study group 3, with locally advanced disease at presentation. Twenty (41%) of the 49 patients presented with primary tumors greater than 10 cm in diameter. Sixteen (33%) of the 49 patients had positive regional lymph nodes at presentation. The overall survival of the series was 30 (65%) of 46. The survival for those treated after 1992 in Intergroup Rhabdomyosarcoma Study group 3 was superior (P = .04) to those treated before 1992 (80% vs 56%).

CONCLUSION

Children in this large African series of genitourinary rhabdomyosarcoma present with greater locally advanced disease (node positive and bulky disease) when compared with the developed world. Improvements in the last 2 decades in local surgical and oncological care have led to an improvement in survival in children with locally advanced disease.