Investigating the Impact of Tumor Biology and Social Determinants on Time to Diagnosis and Stage at Presentation of Wilms Tumor.

Delays in diagnosis and time to diagnosis generally are used interchangeably in cancer disparity research, but these terms may have important differences. Although these terms are related, we hypothesize that time to diagnosis is determined by the aggressiveness of the tumor based on intrinsic factors such as tumor biology, whereas delays in diagnosis are caused by extrinsic factors such as socioeconomic status, leading to presentation at higher stage of disease due to barriers of care. We conducted a retrospective study of 306 patients diagnosed with Wilms tumor at Children's Hospital Colorado between 1971 and 2016 identifying patient barriers as extrinsic markers and using unfavorable histology and loss of heterozygosity as markers of aggressive tumor biology. Multivariable logistic regression was performed. Patients with Medicaid were more likely to present greater than 4 days after initial symptoms compared to those with private insurance, and those with housing concerns were more likely to be diagnosed greater than 9 days from initial symptoms. Tumor biology was noted to be associated with higher stage at diagnosis, but patient barriers were not. These findings suggest the interplay between tumor biology, patient barriers, diagnostic timing, and stage at diagnosis is more complex, multifactorial, and in need of further study.

How to improve initial diagnostic accuracy of kidney tumours in childhood?-A non-invasive approach.

Non-invasive differentiation of paediatric kidney tumours is particularly important in the SIOP-RTSG protocols, which recommend pre-operative chemotherapy without histological confirmation. The identification of clinical and tumour-related parameters may enhance diagnostic accuracy. Age, metastases, and tumour volume (TV) were retrospectively analysed in 3306 patients enrolled in SIOP/GPOH 9, 93-01, and 2001 including Wilms tumour (WT), congenital mesoblastic nephroma (CMN), clear cell sarcoma (CCSK), malignant rhabdoid tumour of the kidney (MRTK), and renal cell carcinoma (RCC). WT was diagnosed in 2927 (88.5%) patients followed by CMN 138 (4.2%), CCSK 126 (3.8%), MRTK 58 (1.8%) and RCC 57 (1.7%). CMN, the most common localized tumour (71.6%) in patients younger than 3 months of age, was diagnosed earliest and RCC the latest (median age [months]: 0 and 154, respectively) both associated with significantly smaller TV (median TV [mL]: 67.2 and 45.0, respectively). RCC occurred in >14% of patients older than 120 months or older than 84 months with TV <100 mL. Receiver operating characteristic analyses discriminated WT from CMN, RCC and MRTK regarding age (AUC = 0.976, 0.929 and 0.791) and TV (AUC = 0.768, 0.813 and 0.622). MRTK had the highest risk of metastasis (37.9%) despite young age, whereas the risk of metastasis increased significantly with age in WT. Age and TV at diagnosis can differentiate WT from CMN and RCC. MRTK must be considered for metastatic tumours at young age. Identification of CCSK without histology remains challenging. Combined with MRI-characteristics, including diffusion-weighted imaging, and radiomics and liquid biopsies in the future, our approach allows optimization of biopsy recommendations and prevention of misdiagnosis-based neoadjuvant treatment.

Differentiation Potential of Hypodifferentiated Subsets of Nephrogenic Rests and Its Relationship to Prognosis in Wilms Tumor.

Background Wilms tumor (WT) is highly curable, although anaplastic histology or relapse imparts a worse prognosis. Nephrogenic rests (NR) associated with a high risk of developing WT are abnormally retained embryonic kidney precursor cells. Methods After pseudo-time analysis using single-cell RNA sequencing (scRNA-seq) data, we generated and validated a WT differentiation-related gene (WTDRG) signature to predict overall survival (OS) in children with a poor OS. Results A differentiation trajectory from NR to WT was identified and showed that hypodifferentiated subsets of NR could differentiate into WT. Classification of WT children with anaplastic histology or relapse based on the expression patterns of WTDRGs suggested that patients with relatively high levels of hypodifferentiated NR presented a poorer prognosis. A WTDRG-based risk model and a clinically applicable nomogram was developed. Conclusions These findings may inform oncogenesis of WT and interventions directed toward poor prognosis in WT children of anaplastic histology or relapse.

Clear cell sarcoma of kidney: A mimicker of Wilms' tumor.

The differential diagnosis for an abdominal mass in a 2-year-old child is broad and includes lesions of renal, hepatic, gastrointestinal, adrenal, and lymphatic origins. Of these, Wilms' tumor and neuroblastoma are the most common tumors, where Wilms' tumor represents about 92% of renal masses in children. Non-Wilms' renal tumors, rhabdoid tumors, and clear cell sarcoma of the kidney (CCSK) are uncommon. CCSK constitutes approximately 3% of all malignant renal tumors in childhood. In this report, we present a child presenting with a huge renal mass consistent with Wilms' tumor on computed tomography and initial biopsy. However, the final pathologic diagnosis after resection revealed CCSK.

Bilateral Wilms tumor in a patient with a horseshoe and duplex kidney: A case report.

The occurrence of horseshoe kidney with duplex urinary collecting systems is rare. Herein, we report a case of bilateral Wilms tumor (BWT) in a patient with a concurrent horseshoe kidney and left duplex kidney, which had not been previously reported. The patient was treated with neoadjuvant chemotherapy, followed by surgical resection and adjuvant chemotherapy. The tumor recurred 6 months postoperatively. A second resection was performed, followed by the administration of chemotherapy and radiotherapy. The patient passed away 15 months after the initial diagnosis of BWT.

Low risk of embryonic and other cancers in PIK3CA-related overgrowth spectrum: Impact on screening recommendations.

The PIK3CA-related overgrowth spectrum (PROS) encompasses various conditions caused by mosaic activating PIK3CA variants. PIK3CA somatic variants are also involved in various cancer types. Some generalized overgrowth syndromes are associated with an increased risk of Wilms tumor (WT). In PROS, abdominal ultrasound surveillance has been advocated to detect WT. We aimed to determine the risk of embryonic and other types of tumors in patients with PROS in order to evaluate surveillance relevance. We searched the clinical charts from 267 PROS patients for the diagnosis of cancer, and reviewed the medical literature for the risk of cancer. In our cohort, six patients developed a cancer (2.2%), and Kaplan Meier analyses estimated cumulative probabilities of cancer occurrence at 45 years of age was 5.6% (95% CI = 1.35%-21.8%). The presence of the PIK3CA variant was only confirmed in two out of four tumor samples. In the literature and our cohort, six cases of Wilms tumor/nephrogenic rests (0.12%) and four cases of other cancers have been reported out of 483 proven PIK3CA patients, in particular the p.(His1047Leu/Arg) variant. The risk of WT in PROS being lower than 5%, this is insufficient evidence to recommend routine abdominal imaging. Long-term follow-up studies are needed to evaluate the risk of other cancer types, as well as the relationship with the extent of tissue mosaicism and the presence or not of the variant in the tumor samples.

Decoding the Possible Molecular Mechanisms in Pediatric Wilms Tumor and Rhabdoid Tumor of the Kidney through Machine Learning Approaches.

Objective: Wilms tumor (WT) and Rhabdoid tumor (RT) are pediatric renal tumors and their differentiation is based on histopathological and molecular analysis. The present study aimed to introduce the panels of mRNAs and microRNAs involved in the pathogenesis of these cancers using deep learning algorithms. Methods: Filter, graph, and association rule mining algorithms were applied to the mRNAs/microRNAs data. Results: Candidate miRNAs and mRNAs with high accuracy (AUC: 97%/93% and 94%/97%, respectively) could differentiate the WT and RT classes in training and test data. Let-7a-2 and C19orf24 were identified in the WT, while miR-199b and RP1-3E10.2 were detected in the RT by analysis of Association Rule Mining. Conclusion: The application of the machine learning methods could identify mRNA/miRNA patterns to discriminate WT from RT. The identified miRNAs/mRNAs panels could offer novel insights into the underlying molecular mechanisms that are responsible for the initiation and development of these cancers. They may provide further insight into the pathogenesis, prognosis, diagnosis, and molecular-targeted therapy in pediatric renal tumors.

Immunohistochemical expression of P53 protein in nephroblastoma: a predictor of unfavorable prognosis.

OBJECTIVE: Immunohistochemical expression of P53 protein is so closely related to status of mutation of P53 gene which is tightly linked with pathogenesis of nephroblastoma or Wilms tumor. This study aims to determine the immunohistochemical expression of P53 protein and its predictors in formalin-fixed paraffin-embedded tissue blocks of patients with nephroblastoma. MATERIALS AND METHODS: A series of 83 histologically diagnosed cases of nephroblastoma from formalin-fixed paraffin-embedded tissue blocks archived at the Department of Pathology, Makerere University, in Kampala, Uganda, were analyzed. Monoclonal anti-p53 antibody (DO-7, DAKO) was used to assess the expression of P53 protein expression. Multivariable logistic regression analysis was performed to determine the predictors of P53 protein immunohistochemical expression, and statistical significance was considered when p-value was less than 0.05. RESULTS: Most (42.2%, n = 35) of the cases were in advanced tumor stages (III-V), and almost one-quarter (21.7%, n = 18) of the cases were in high-risk group. The immunohistochemical expression of P53 protein was (8.4%, n = 7), and there were more (83.3%, n = 5) positive anaplastic cases for P53 protein compared with (2.6%, n = 2) of P53 expression for non-anaplastic cases. High risk (AOR = 3.42, 95% CI = 7.91-12.55, p = 0.037) and anaplasia (AOR = 1.41, 95% CI = 13.85-4.46, p = 0.001) were potential predictors of immunohistochemical expression of P53 protein. CONCLUSION: Most of patients with nephroblastoma in resources-limited settings are diagnosed with advanced clinical stages. Association of P53 protein with anaplasia found in this study indicates the possibility of having novel target therapy for treatment of patients with anaplastic form of nephroblastoma with a focus of identifying molecules that lead to its suppression in such subpopulations of patients with nephroblastoma.

Unusual association of Wilms' tumor with cystic diseases of kidney: A pathologic surprise.

Wilms' tumor (or nephroblastoma) is the most common renal malignancy in the pediatric population which consists of blastemal, epithelial, and stromal elements in variable proportions. The occurrence of renal cysts in children and infants is a rare phenomenon and is possibly an outcome of developmental aberrations in mesonephric blastema. The coincidental association of nephroblastoma with renal cysts is a very rare finding. Here, we describe two cases of Wilms' tumor with an unusual association between glomerulocystic kidney disease and multicystic dysplastic kidney.

Alterations of miRNA Expression in Diffuse Hyperplastic Perilobar Nephroblastomatosis: Mapping the Way to Understanding Wilms' Tumor Development and Differential Diagnosis.

Wilms' tumor (WT) is the most common renal malignancy in children. In diffuse hyperplastic perilobar nephroblastomatosis (DHPLN), nephrogenic rests result in a bulky enlargement of the kidney, a condition considered as a premalignant state before WT. Despite relevant clinical differences between WT and DHPLN, they are often challenging to distinguish based on histology. Molecular markers would improve differential diagnosis, but none are available at present. In our study, we investigated the potential of microRNAs (miRNAs) as such biomarkers, also aiming to shed light on the chronological order of expression changes. Formalin-fixed, paraffin-embedded (FFPE) samples from four DHPLN cases and adjacent healthy tissues were tested using a PCR array containing primers for 84 miRNAs implicated in genitourinary cancer. Expression in DHPLN was compared to WT data available in dbDEMC. Let-7, miR-135, miR-146a-5p, miR-182-5p, miR-183-5p, miR-20b-3p, miR-29b-3p, miR-195-5p and miR-17-5p showed potential to be used as biomarkers to distinguish WT and DHPLN in cases when traditional differential diagnosis is inconclusive. Our study also revealed miRNAs which may play a role in the initial steps of the pathogenesis (at a precancerous stage) and ones which become deregulated later in WT. More experiments are needed to confirm our observations and find new candidate markers.

Concurrent Hepatoblastoma and Wilms Tumor Leading to Diagnosis of Beckwith-Wiedemann Syndrome.

Beckwith-Wiedemann syndrome (BWS) is an epigenetic overgrowth disorder and cancer predisposition syndrome caused by imprinting defects of chromosome 11p15.5-11p15.4. BWS should be considered in children with atypical presentations of embryonal tumors regardless of clinical phenotype. Risk of malignancy correlates with specific molecular subgroups of BWS making molecular subclassification important for appropriate cancer screening. We report the first case of concurrent embryonal tumors in a phenotypically normal child, leading to the diagnosis of BWS with paternal uniparental disomy and describe the molecular classification of BWS as it relates to malignancy risk, along with approach to management.

Lateralized overgrowth as a guiding sign of abdominal neoplasms for pediatric orthopedic surgeons.

OBJECTIVES: This study aims to increase the awareness of the association between lateralized overgrowth (LO) and abdominal tumor among the pediatric orthopedic community and to evaluate its incidence in our center. PATIENTS AND METHODS: Between January 1997 and December 2021, a total of 166 patients with Wilms tumors and hepatoblastomas were retrospectively analyzed. Data including age, sex, initial clinical signs (hematuria, abdominal mass with or without general discomfort), type of asymmetric regional body overgrowth (isolated or in relation with any syndrome), and tumor stage at diagnosis were recorded. In addition, age at which asymmetric regional body overgrowth was described and age at the time of tumor diagnosis were noted. RESULTS: Of a total of 166 patients, 133 were diagnosed with Wilms tumors (nephroblastomas) and 33 were diagnosed with hepatoblastomas. In 94% of the cases, the initial clinical signs were an abdominal mass and/or hematuria. Overall, five (3%) patients presented with LO. Four patients with Wilms tumor presented it at the initial clinical examinations. In three of these cases (2.3%), we found it isolated and, in the remaining patient (0.75%), it was associated with Beckwith-Wiedemann spectrum. Only one patient affected from hepatoblastoma (3%) presented with an isolated LO at the time of tumor diagnosis. CONCLUSION: Our study results show an incidence of LO in relation to intra-abdominal tumors of 3%. The latest updates recommend genetic testing to identify subgroups with a higher risk for tumor development that are more likely to benefit from tumor protocol surveillance.

Renal Yolk Sac Tumor Clinically Misdiagnosed as Nephroblastoma: A Case Report.

Background: Yolk sac tumor is a germ cell tumor (GCT) that occurs in infants and adolescents and affects various sites. There is a trend to treat pediatric renal tumors before a tissue diagnosis. We report a renal yolk sac tumor clinically misdiagnosed as Wilms tumor, based on ultrasound (US) and MRI.Case Report: This 21-month-old male infant was discovered to have a space occupying lesion in the right kidney. Because the tumor was large, initial radiotherapy preceded surgical resection. Histologically, the tumor was a yolk sac tumor.Conclusion: Imaging examination of renal yolk sac tumor can easily be misdiagnosed as Wilms tumor. SIOP treatment plan for Wilms tumor requires preoperative chemotherapy, which is different from the treatment regimen for yolk sac tumor. Preoperative alpha-fetoprotein could have been helpful in avoiding this clinical misdiagnosis.

Primary Pure Intrarenal Yolk Sac Tumor in 1.5-Year-Old Boy-A Rare Case Report.

Germ cell tumors primarily arise in gonads and extragonadal germ cell tumors, an uncommon entity, originates usually along the midline. Here, we report the fifth example of intrarenal pure yolk sac tumor in a 1.5-year-old boy who presented with abdominal pain and underwent excision of the mass for suspected Wilms tumor. On histopathology and immunohistochemistry, a diagnosis of a yolk sac tumor was rendered. Postoperative serum alpha-fetoprotein levels were 21 000 ng/dl. The purpose of this report is to emphasize the importance of suspecting a germ cell tumor as one of the differential diagnoses of a suspected case of Wilms tumor and the significance of evaluating serum alpha-fetoprotein levels preoperatively.

Pediatric Primary Yolk Sac Tumour of the Kidney: Recommendations for Pretreatment Diagnosis.

Introduction Although nephroblastomas are frequently treated without prior biopsy, there are the occasional other pediatric renal tumors that require different management. In the literature, there are around 30 primary renal germ cell tumors (GCT), including four cases of Yolk sac tumor (YST). We present another primary renal YST.Case report: A five-year-old boy was diagnosed as Wilms tumor on radiology and needle biopsy. He received chemotherapy, with no response. The post-chemotherapy resection specimen revealed a YST.Conclusion: Renal YST may be indistinguishable from Wilms tumor clinically and radiologically. For pre-biopsy chemotherapy management protocols, serum tumor markers such as AFP may be recommended to identify the occasional GCT, including YST. Pre-chemotherapy needle biopsies may lead to misdiagnosis, and may require confirmation by an experienced pathologist or central review.

A rare case of extrarenal Wilms tumor of the uterine corpus: comprehensive genomic profile and review of the literature.

Wilms tumor (WT), or nephroblastoma, is an uncommon malignant neoplasm occurring in the kidney of pediatric patients. Its extrarenal location is extremely rare and has been reported in various sites, including the female genital tract, with only 9 cases arising in the uterine corpus. We present the case of an adult woman who underwent total abdominal hysterectomy due to a uterine mass causing persistent abdominal pain. The characteristic triphasic morphology (composed of epithelial, stromal, and blastemal elements) supported by a broad immunohistochemical panel, along with the imaging exclusion of a renal neoplasm, was diagnostic of WT of the uterus. For the first time, a comprehensive genomic profiling of a uterine primary WT was also performed by next-generation sequencing, disclosing alterations at the level of copy number variations in the genes ERBB2, FGFR23, FGF6, FGFR2, and RPS6KB1. All previously reported uterine cases were reviewed, with a summary of their main clinicopathologic characteristics, and the main differential diagnoses are presented. Further reports are needed to improve our knowledge about prognostic factors, clinical behavior and molecular alterations that could guide appropriate therapeutic decision making.

Extrarenal Wilms' Tumour of the Ovary: A case report.

Wilms' tumour (nephroblastoma) is the most common abdominal malignancy in children. Extrarenal Wilms' tumour is rare, with limited reports in the literature. We report a two-year-old girl who presented to a tertiary care hospital in Muscat, Oman, in 2019 with an abdominal mass. The patient was diagnosed with unilateral ovarian Wilms' tumour (initially diagnosed by closed biopsy and confirmed later by histopathology study of the excised tumour). This report highlights the unusual location and presentation of Wilms' tumour and presents the medical challenge in both the initial clinical impression and pathological diagnosis. Furthermore, this report details the therapeutic plan and shows the good outcome achieved by using the classic renal Wilms' tumour therapy protocols.