Pediatric Renal Tumors Research Articles

Coexisting Congenital Mesoblastic Nephroma and Lissencephaly: Unique Case Report with Pathological Analysis and Its Clinical Significance

Background: Congenital mesoblastic nephroma represents 3–10% of all pediatric renal tumors. With the advancement of ultrasound diagnostics and magnetic resonance imaging, the diagnosis of this renal neoplasm is increasingly being established prenatally and at birth. It usually presents as a benign tumor, but it can severely affect pregnancy outcomes, contributing to perinatal morbidity and mortality. Lissencephaly belongs to a rare category of neurodevelopmental disorders marked by the absence of a substantial reduction in the typical folds and grooves in the cerebral cortex. The prognosis for patients with lissencephaly is extremely poor, carrying with it a high mortality rate. Case Presentation: We present a case of congenital mesoblastic nephroma (CMN) diagnosed with polyhydramnios at 28 weeks of gestation, which led to preterm delivery at 29 weeks and a fatal outcome for the newborn. Histopathological examination confirmed the diagnosis of CMN along with fetal pachygyria/lissencephaly. The aim of this study is to point out the characteristics and unique correlation between CMN and lissencephaly, and to illustrate the histopathological features of CMN and lissencephaly through an educational example derived from our presented index case. To the best to our knowledge, the association of CMN with lissencephaly has not been described in the literature so far. Conclusions: Outlining the prenatal progression of CMN and the outcome of pregnancies involving fetal CMN and lissencephaly, this case underscores the importance of comprehensive ultrasound examinations, including central nervous system evaluation, to identify potential coexisting anomalies and refine prenatal diagnostic practices.

Paediatric renal tumours: an update on challenges and recent developments.

Paediatric renal tumours include a broad range of neoplasms which largely differ, but also overlap to a smaller extent, with adult kidney cancer. These include the embryonal tumour nephroblastoma, which accounts for the majority of cases of kidney cancer in the first decade of life and, despite boasting a cure in ~ 90% cases, still presents clinical challenges in a small proportion of cases. A variety of less common mesenchymal tumours, including the mostly indolent congenital mesoblastic nephroma, clear cell sarcoma of kidney which continues to be associated with poor outcomes for higher stage disease, and the typically lethal malignant rhabdoid tumour, form the bulk of the remaining presentations in the first decade. All three of these represent the intrarenal form of a wider 'family' of genetically related and histologically overlapping entities occurring in soft tissue and other anatomical locations. The latter two are examples of aggressive 'epigenetic' tumours driven by dysregulation of chromatin. In the second decade of life, renal cell carcinoma dominates, and with molecular characterisation many distinct subtypes are now described. Herein we discuss the developments in relation to diagnostic categorisation of paediatric renal cancers and how deeper understanding of the underlying biology is already providing therapeutic opportunity, while also focussing on the challenges that remain for the pathologist.

A Unique Case of Cystic Partially Differentiated Nephroblastoma Associated With Botryoid Intralobar Nephrogenic Rests.

Cystic partially differentiated nephroblastoma (CPDN) is a rare pediatric renal tumor composed of multiple cystic spaces divided by septa containing immature nephrogenic elements. The presence of expansile solid areas in the septa of such a lesion indicates an alternative diagnosis of Wilms tumor (WT). We present a unique case of CPDN associated with grossly visible polypoid proliferations, which histologically correspond to botryoid growth of intralobar nephrogenic rests. Correct pathological diagnosis of CPDN and its differentiation from cystic WT can be challenging, but is critical, because of the distinct treatment approaches and prognoses of these entities, since CPDN is a low-risk tumor not requiring further postoperative therapy.

Long-Term Survey of Japanese Children with Recurrent Nephroblastoma: A Report from Japan Children’s Cancer Group

In prospective Japanese studies of pediatric renal tumors, 5-year event-free survival and overall survival (OS) for patients with nephroblastoma ranges from 75–90% and 89–97%, respectively. However, treatments strategies for recurrent nephroblastoma in Japanese patients remain unclear. This retrospective study aimed to inform the development of treatment strategies by analyzing the long-term results and side effects of salvage therapies for recurrent nephroblastoma in Japan. A questionnaire survey involving 41 institutions (74 patients) collected clinical data on recurrent cases reported to the Renal Tumor Committee of the Japan Children’s Cancer Group. Survey forms from 54 cases were evaluated. Median time to recurrence was 9.5 months among 51 patients without underlying disorders. Recurrence occurred at lung-only in 18 patients and at other sites in 33. The 5-year OS for all 51 patients was 70.6%, with recurrent disease causing death in 15 patients and one patient dying from treatment-related complications. Patients with lung-only recurrence had higher 5-year OS rates than those with other-site recurrence. Initial chemotherapy intensity also affected prognosis, with lower intensity associated with higher 5-year OS. In 17 survivors with lung-only recurrence, the most frequent treatment approach combined chemotherapy, surgery and radiotherapy. Conventional chemotherapy included platinum-containing regimens and/or Regimen I-based treatment containing cyclophosphamide and etoposide. Salvage therapies showed remarkable effectiveness for patients with lung-only recurrence or low intensity of the initial chemotherapy, highlighting the need to standardize prospective studies for post-recurrence treatment and identify risks of late complications for long-term survivors.

Robot-assisted resection of renal tumor in children and comparison with laparoscopic surgery

BackgroundRobot-assisted surgery (RAS) is being performed with increasing frequency in pediatric oncology. We report our experience with RAS for renal tumors in children and compare the outcomes between RAS and laparoscopic surgery (LAS).MethodsA total of 23 patients with renal tumor who underwent minimally invasive surgery (MIS) between January 2020 and December 2023 were included in the study. The inclusion criteria enrolled in this study was unilateral tumors with maximum tumor diameter less than 10 cm. Patients who had enlarged lymph node, venous thrombosis, preoperative tumor rupture, bilateral renal tumor, or extrarenal extension on imaging were deemed contraindications and excluded. Patient demographics, operative details, postoperative outcomes and follow-up were recorded.ResultsAmong these patients, 17 underwent RAS and 6 underwent LAS. In the RAS group, the median age was 64 months (range, 9–156) with a median weight of 19.48 kg (range, 8.4–46.5); the maximum tumor diameter at operation was 55.65 mm (range, 22–88); the operation time was 188.8 min (range, 120–210), the intraoperative blood loss was 20 ml (range, 5–50), and the length of postoperative hospital stay was 4 days (range 1–9). There was no significant difference in patients’ age, weight, location, tumor size, histological pattern and operation time between the two groups (P > 0.05). The RAS group had a significantly less intraoperative blood loss (P = 0.026) and less length of postoperative stay (P = 0.01) than the LAS group.ConclusionOur initial experience suggested that RAS in pediatric renal tumor was feasible and safe, and it reduced surgical trauma and accelerate postoperative recovery for the patients. Due to the limitations of sample size and study quality, the clinical importance of these findings still needs to be further verified.

Outcomes of Pediatric Renal Tumors over 5 Years in Regional Cancer Center, Kidwai Memorial Institute of Oncology, Bengaluru, South India

Wilms' tumor (WT) is the most common malignant renal tumor in the pediatric population and it is managed with a multimodal treatment. Improvements in chemotherapy and risk stratification have led to dramatic improvement in the prognosis of renal tumors, which was once a lethal malignancy. Seventy-three patients with histopathologically proven diagnosis of renal tumor who received treatment from January 2011 to December 2015 were included for analysis. Eight children underwent upfront nephrectomy. The patients were analyzed for event-free survival and overall survival. The outcomes were correlated with age, sex, stage at presentation, and histology. A favorable histology was found in 74% patients, while an unfavorable histology was observed in 26% of the cases. The 5-year event-free survival was 82.7% and overall survival was 87.6%. The stage at presentation had a prognostic value (p < 0.001). Tumor histology was the single most important factor in predicting the survival.

8120 Effective Management of Neonatal Hypercalcemia in Congenital Mesoblastic Nephroma: A Case Report on the Use of Calcitonin

Abstract Disclosure: C.S. Galvez: None. K. Rifai: None. C. Moorthy: None. S. Chheda: None. M. Zerah: None. Introduction: Pediatric patients with hypercalcemia of malignancy are typically treated with hyperhydration, loop diuretics and bisphosphonates. Calcitonin, a peptide functionally antagonizes the effects of PTH. Calcitonin has limited pharmacokinetic data in neonates, especially those with Congenital Mesoblastic Nephroma (CMN), making treatment challenging with unclear safety and efficacy parameters. We present the fourth published case describing the use of calcitonin for likely PTH-rP-mediated severe hypercalcemia in a neonate with CMN. Clinical Case: A 15-day-old late preterm male, presented with lethargy, poor feeds, severe failure to thrive and a large abdominal mass. The mother is a G4P4, with good prenatal care. On admission, the patient was hypertensive (138/84 mmHg) and appeared dehydrated. Physical examination revealed a firm mass in the right abdomen crossing the midline. Serum calcium levels were 13.5 mg/dL (normal 9.0-10.9 mg/dL), with an ionized calcium 1.71 mmol/L (normal 1.15 and 1.30 mmol/L). Abdominal ultrasound showed a large, 9.1 x 8 cm dominant solid right renal mass, most likely CMN, with left-sided medullary nephrocalcinosis. Cardiac Echo and EKG were within normal limits. The patient received hydration, nicardipine (titrated to decrease blood pressure by 10-15 mmHg per day) and furosemide at 1 mg/kg/day IV q6h. Due to the persistence of hypercalcemia after 24 hours of treatment (14.7 mg/dL serum calcium with ionize of 1.81 mmol/L), the patient received one dose of calcitonin (4 units/kg subcutaneously), resulting in a decrease in serum calcium to 11.5 mg/dL in 4 hours. The patient underwent a successful radical right uretero-nephrectomy, with post-surgery improvement of neurological, cardiovascular and electrolyte status. Unfortunately, PTH-rP sample was insufficient. Pathology reported CMN of the cellular type. CMN is a rare tumor with low malignant potential, representing approximately 3% of all pediatric renal tumors. It is the most common renal neoplasm diagnosed in the first 6 months of life. The most common symptom is an abdominal mass (76%), with hypertension (19%). Hypercalcemia was reported in only 4% which can be secondary to paraneoplastic secretion of PTH or PTH-rP. Conclusion: This case represents the fourth instance of calcitonin use in a neonate with CMN to manage persistent hypercalcemia. Subcutaneous administration of calcitonin at 4 units/kg proved effective with a short onset of action (within 2 hours) and duration of 6 to 8 hours, making it a viable alternative to bisphosphonates (action around 48 hours and duration of 7 to 14 days). Calcitonin's advantages include less significant side effects and a faster resolution of complications like "Hungry bone Syndrome." The flexibility of repeated dosing every 6 hours, with the option to increase the dose, if necessary, adds to its clinical utility. Presentation: 6/3/2024

Lymph Node Sampling in Pediatric Renal Tumors: Survey of Current Practices and Impact of Education

ObjectiveTo characterize how often and to what extent surgeons are willing to perform retroperitoneal node sampling (RPLNS) for a unilateral renal tumor, and whether they would be encouraged to change goal number of LNs after “targeted education” (TE) MethodsA survey with selected demographic and LN sampling practice questions was distributed to practicing members of the Society of Pediatric Urology (SPU). After answering a seven-question questionnaire, participants were provided with an abstract on the adequacy of LN yield for staging. This served as the TE and then participants were asked to answer a final question on LN sampling goals. ResultsA total of 76 (19.2%) of participants, out of 395 invitations, returned complete surveys. Cross tabulation between sampling goals before and after TE showed that among surgeons sampling 1-4 nodes, 13/24 (54.16%) would be willing to change their practice and sample ≥10 nodes. A higher proportion of participants who were already systematically surveilling 5-9 LNs would be willing to change their current practice: 30/39 (77%) would now aim for ≥10 LNs. On multivariate analysis, only willingness to sample ≥5 LNs in current practice was predictive of changing to sample ≥10 LNs after TE. ConclusionRetroperitoneal LNs are currently still under sampled by pediatric urologists operating on children and adolescents with unilateral renal tumors. Targeted education appears to encourage change in LN sampling practices.

Rare case of stromal predominant Wilm's tumour with rhabdomyoblastic differentiation in FNAC smears.

The FNAC smear and histopathology of stromal predominant Wilm's tumour with rhabdomyoblastic Differentiation along with immunostaining in a 7-year-old male. In this paper, the diagnostic potential of FNAC in identifying rare histological variants of paediatric renal tumours is highlighted.

Worse Wilms' Tumor Outcomes Associated With Chemical Complementarity for Multiple T-Cell Receptor CDR3-CMV Epitope Pairs.

Wilms' tumors are pediatric renal tumors that generally have a good prognosis and outcomes. Viral illnesses have been linked to development of neoplasms and should be considered as a factor that could modulate overall survival. We considered recently developed adaptive immune receptor, genomics and bioinformatics approaches to assess the potential impact of cytomegalovirus (CMV) infections in Wilms' tumor. T-cell receptor (TCR) complementarity determining region-3 (CDR3) amino acid sequences from Wilms' tumor specimens represented by the Therapeutically Applicable Research to Generate Effective Treatments dataset were compared with known anti-CMV TCR CDR3s, indicating that cases representing the anti-CMV TCR CDR3s had worse outcomes. Then, a chemical complementarity scoring approach for the Wilms' tumor, TCR CDR3s and a series of CMV antigens further indicated that cases representing a higher chemical complementarity to the CMV antigens had worse outcomes. Overall, we present a potentially novel method to assess CMV infections and identify patients who could benefit from therapies that address such infections.

Assessment of the Circulating PD-1 and PD-L1 Levels and P53 Expression as a Predictor of Relapse in Pediatric Patients with Wilms Tumor and Hypernephroma.

Background/Objectives: Wilms tumor (WT) is the most common form of pediatric renal tumor, accounting for over 90% of cases followed by hypernephroma. Some pediatric patients with WT (10%) experience relapse or metastasis and have poor survival rates. PD-L1 assists cancer cells in escaping damage from the immune system. P53 mutations are found in relapsed WT tumor samples. We hypothesized that testing circulating PD-1 and PD-L1 and P53 expression levels could offer a simple method to predict patient relapse and explore novel treatments for pediatric WTs and hypernephroma. Methods: Flow cytometric detection of cPD-1, cPD-L1, and P53 expression in relapsed and in-remission WT and hypernephroma before and after one year of chemotherapy was performed. Results: Our data shows increased levels of cPD-L1 in relapsed pediatric patients with WT or hypernephroma before and after chemotherapy. There were also slight and significant increases in cPD-1 levels in relapsed groups before chemotherapy. Additionally, we observed significant decreases in P53 expression after one year of chemotherapy in relapsed pediatric patients. Conclusions: Our study found that circulating PD-L1 can be used as a predictor marker for WT and hypernephroma relapse. In conclusion, these circulating markers can assist in monitoring relapse in WT and hypernephroma patients without the need for several biopsies.

Direct correlation of MR-DWI and histopathology of Wilms' tumours through a patient-specific 3D-printed cutting guide.

The International Society of Paediatric Oncology-Renal Tumour Study Group (SIOP-RTSG) discourages invasive procedures to determine the histology of paediatric renal neoplasms at diagnosis. Therefore, the histological subtype of Wilms' tumours (WT) is unknown at the start of neoadjuvant chemotherapy. MR-DWI shows potential value as a non-invasive biomarker through apparent diffusion coefficients (ADCs). This study aimed to describe MR characteristics and ADC values of paediatric renal tumours to differentiate subtypes. Children with a renal tumour undergoing surgery within the SIOP-RTSG 2016-UMBRELLA protocol were prospectively included between May 2021 and 2023. In the case of a total nephrectomy, a patient-specific cutting guide based on the neoadjuvant MR was 3D-printed, allowing a correlation between imaging and histopathology. Whole-tumour volumes and ADC values were statistically compared with the Mann-Whitney U-test. Direct correlation on the microscopic slide level was analysed through mixed model analysis. Fifty-nine lesions of 54 patients (58% male, median age 3.0 years (range 0-17.7 years)) were included. Forty-four lesions involved a WT. Stromal type WT showed the lowest median decrease in volume after neoadjuvant chemotherapy (48.1 cm3, range 561.5-(+)332.7 cm3, p = 0.035). On a microscopic slide level (n = 240 slides) after direct correlation through the cutting guide, stromal areas showed a significantly higher median ADC value compared to epithelial and blastemal foci (p < 0.001). With a cut-off value of 1.195 * 10-3 mm2/s, sensitivity, and specificity were 95.2% (95% confidence interval 87.6-98.4%) and 90.5% (95% confidence interval 68.2-98.3%), respectively. Correlation between histopathology and MR-DWI through a patient-specific 3D-printed cutting guide resulted in significant discrimination of stromal type WT from epithelial and blastemal subtypes. Stromal Wilms' tumours could be discriminated from epithelial- and blastemal lesions based on high apparent diffusion coefficient values and limited decrease in volume after neoadjuvant chemotherapy. This may aid in future decision-making, especially concerning discrimination between low- and high-risk neoplasms. MR-DWI shows potential value as a non-invasive biomarker in paediatric renal tumours. The patient-specific cutting guide leads to a correlation between apparent diffusion coefficient values and Wilms' tumour subtype. Stromal areas could be discriminated from epithelial and blastemal foci in Wilms' tumours based on apparent diffusion coefficient values.

Intraparenchymal Indocyanine Green Use Improves Nodal Yield During Minimally Invasive Tumor Nephrectomy in Children.

Introduction: Correctly identifying positive lymph nodes associated with pediatric renal tumors is key to guiding management. Recommended targets for lymph node sampling are commonly missed during tumor nephrectomy, particularly if minimally invasive surgery (MIS) is performed. Indocyanine green (ICG) is used for lymph node mapping in adult oncology with excellent efficacy and safety profile. Materials and Methods: A prospective study was undertaken at a single-quaternary-level pediatric surgery center. All patients undergoing MIS radical or partial nephrectomy for renal tumors 2016-2023 were included. Patients managed from 2020 onwards received intra-parenchymal ICG prior to lymph node sampling. Main Results: Twenty-five patients underwent MIS nephrectomy at mean age 2 years 10 months. Eighteen patients were pre-ICG and 7 received ICG. ICG administration successfully demonstrated fluorescent nodes in all patients. Median number of nodes sampled was three pre-ICG and seven with ICG (P = 0.009). Forty-six nodes were sampled across 7 ICG patients-33 fluorescent, 10 non-fluorescent, and 3 identified histologically. Three nodes overall contained active disease, two pre-ICG and one fluorescent node with ICG. Neither operative time (180 pre-ICG versus 161 minutes ICG, P = 0.7) nor length of stay (72 versus 84 hours, P = 0.3) were significantly affected by ICG administration. There were no adverse events associated with ICG use. Conclusions: ICG is safe and effective at identifying nodes in MIS resection of pediatric renal tumors with the potential to increase the number of nodes sampled. Further research is needed, specifically a randomized control trial with extended follow-up.

Current surgical approaches to pediatric renal tumors.

Pediatric renal tumors are among the most common pediatric solid malignancies. Surgical resection is a key component in the multidisciplinary therapy for children with kidney tumors. Therefore, it is imperative that surgeons caring for children with renal tumors fully understand the current standards of care in order to provide appropriate surgical expertise within this multimodal framework. Fortunately, the last 60years of international, multidisciplinary pediatric cancer cooperative group studies have enabled high rates of cure for these patients. This review will highlight the international surgical approaches to pediatric patients with kidney cancer to help surgeons understand the key differences and similarities between the European (International Society of Pediatric Oncology) and North American (Children's Oncology Group) recommendations.

Twinning to reduce research and innovation inequalities in paediatric solid tumours across Europe

Inequalities in research and innovations affect childhood cancer survival across Europe. Vilnius University Hospital Santaros Klinikos (VULSK, the coordinator) and eight research-intensive institutions from seven European countries implemented the TREL project (Twinning in Research and Education to improve survival in childhood solid tumours in Lithuania) supported by the Horizon 2020 Widening programme. TREL aimed to enhance translational, clinical, and survivorship research in paediatric CNS, neuroblastoma, and renal tumours to improve future treatment outcomes in Lithuania. From January 2021 to December 2023, 49 VULSK professionals and 55 peers from partner institutions collaborated in this twinning program. Achievements after three years were: nine educational events, the initiation of basic and clinical research on fertility preservation, ten VULSK researchers joining international research groups, six signed agreements to participate in international academic clinical trials and the implementation of the European Survivorship Passport. Thirty patients received individual treatment recommendations following multidisciplinary discussions with experts from partner institutions. Twenty-five rare genetic variants were classified by the twinning bioinformatician teams with direct consequences on patient management. In conclusion, coordination of the Horizon 2020 project enhanced VULKS’s research capacities, networking channels and attractiveness for industry and academia-initiated innovative actions that will improve survival rates in the long run.

Can non-contrast magnetic resonance imaging replace contrast-enhanced computerized tomography in the local staging of pediatric renal tumors?

BackgroundRenal tumors account for approximately 6–7% of the total incidence of pediatric cancers. Wilms tumor (WT) is the most common renal malignancy observed in the pediatric population under 5 years old. Computed tomography (CT) is used for staging of the renal tumors. Magnetic resonance imaging (MRI) offers enhanced soft tissue resolution and provides more comprehensive insights into tumor extension through the capsule, including tumor infiltration into the renal vein or IVC. MRI is a noninvasive imaging modality that does not involve any radiation hazards, making it safe for children. In addition, MRI can be performed without the administration of contrast agents in patients with impaired renal function. Therefore, MRI plays a vital role in screening, staging, preoperative evaluation, and follow-up. Diffusion-weighted imaging (DWI) is a functional tool that aids in locating the most receptive tumoral region to guide confirmatory biopsies. In this study, we aim to evaluate the potential value of non-contrast MRI in staging pediatric renal tumors compared to contrast-enhanced CT.ResultsThis study included 50 patients presented with renal mass, with ages ranging from 1 to 8 years and a mean age of 4.27 ± 1.27 (mean ± SD). The final diagnosis was Wilm’s tumor at 86%, clear cell sarcoma at 4%, rhabdoid tumor at 4%, rhabdomyosarcoma at 2%, and nephroblastomatosis with no malignant transformation at 4%. CT accurately diagnosed stages 4 and 5 in agreement with pathological findings while upstaging the other cases, with a CT sensitivity of 90.91%, specificity of 82.35%, PPV of 92%, and NPV of 84%. MRI is superior to CT in stages 1 and 3, accurately diagnosing stages 2, 4, and 5, with a sensitivity of 93.30%, specificity of 95.65%, PPV of 95%, and NPV of 97%.ConclusionsNon-contrast MRI could be considered the optimal radiation-free imaging modality in staging pediatric renal tumors mainly Wilm’s tumor as it offers high sensitivity and specificity of capsular and vascular infiltration, compared to contrast-enhanced CT especially in cases with impaired renal functions.

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

Introduction: Renal cell carcinoma (RCC) is a very rare pediatric renal tumor. Robust evidence to guide treatment is lacking and knowledge on targeted therapies and immunotherapy is mainly based on adult studies. Currently, the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG) 2016 UMBRELLA protocol recommends sunitinib for metastatic or unresectable RCC. This retrospective study describes the effects of tyrosine kinase inhibitors (TKI), anti-programmed cell death 1 (PD-(L)1) monoclonal antibodies, and immunotherapeutic regimens in advanced-stage and relapsed pediatric RCC. Of the 31 identified patients (0-18 years) with histologically proven RCC, 3/31 presented with TNM stage I/II, 8/31 with TNM stage III, and 20/31 with TNM stage IV at diagnosis. The majority were diagnosed with translocation type RCC (MiT-RCC) (21/31) and the remaining patients mainly presented with papillary or clear-cell RCC. Treatment in a neoadjuvant or adjuvant setting, or upon relapse or progression, included mono- or combination therapy with a large variety of drugs, illustrating center specific choices in most patients. Sunitinib was often administered as first choice and predominantly resulted in stable disease (53%). Other frequently used drugs included axitinib, cabozantinib, sorafenib, and nivolumab; however, no treatment seemed more promising than sunitinib. Overall, 15/31 patients died of disease, 12/31 are alive with active disease, and only four patients had a complete response. The sample size and heterogeneity of this cohort only allowed descriptive statistical analysis. This study provides an overview of a unique series of clinical and treatment characteristics of pediatric patients with RCC treated with targeted therapies.

Update on Management of Pediatric Renal Neoplasms

Update on Management of Pediatric Renal Neoplasms

Clinicopathological assessment of renal tumors in pediatric age group in a sample of Iraqi patients

Background: According to the Iraqi Cancer Registry, renal carcinoma is the 13th most common carcinoma, with 798 registered cases in 2020 and 418 deaths. Methods: This is a cross sectional retrospective study that includes the analysis of 116 randomly selected sample of pediatric patients (74 nephrectomies and 42 biopsies) sent to the Teaching Laboratories of AL-Emamain AL-Kadhmain city (AS), Baghdad medical city, and private laboratories from January 2019 to January 2023. Results: Histopathological diagnosis revealed a ratio from malignant to benign of 7.4:1. Wilm’s tumor was the most common malignant tumor (65.5%), while multicystic renal dysplasia was the most common benign tumor (7.8%). Abdominal pain was the most common clinical feature (67.2%), followed by abdominal mass (20.7%). Regarding malignant cases, Pathological stage I was the most common (39.0%). As for the histopathological subtype, triphasic type was the most common (57.1%), followed by the biphasic type (10.5%). Conclusions, Malignant tumors make up the vast majority of renal tumors. Wilm tumor is the predominant malignant tumor. Fortunately, most cases of Wilm tumors exhibited an early stage and favorable histology. Neuroblastoma was the second most common malignant tumor. The abdominal lump is the most common presentation of pediatric renal tumor.

Redo nephron-sparing surgery in stage V pediatric renal tumors – A report from the SIOP/GPOH study group for renal tumors

PurposeNephron-sparing Surgery (NSS) is the surgical treatment of choice in children with bilateral renal tumors or in syndromatic patients. With an increasing role of this surgical approach, there is also an increased number of tumor relapses after NSS. Aim of this study was to evaluate a second (“Redo-“) NSS in children with relapsed renal tumors. Materials and methodsWe retrospectively analysed patients undergoing Redo-NSS for relapsed kidney tumors between 2009 and 2021 at our institution, which represents a national reference center of the SIOP/GPOH renal tumor study group. ResultsNine patients (5 girls, 4 boys) underwent Redo-NSS with resection of 15 lesions. Mean age at surgery was 58 months (12-137), mean operative time for Redo-NSS was 195 min (137-260). R0 resection status was achieved in all children. Two patients had second relapses, one of them was resected via NSS, the other child underwent tumor nephrectomy. Two patients with anaplastic relapses died from combined second relapses. Thus, 7/9 patients are alive without evidence of disease, an impaired renal function was observed in one child. Mean follow-up after Redo-NSS was 35 months (6-49). ConclusionsIn renal tumor relapses, Redo-NSS can be performed with satisfactory oncological and functional results. Occurrence of diffuse anaplasia should possibly refrain from this approach. Further evaluation in international multicenter analyses are necessary for a definitive determination of Redo-NSS.