Background/Objectives: The Tc-99m dimercaptosuccinic acid (DMSA) renal scan clearly images the renal cortex, highlighting functional tissue areas and indicating regions of renal scarring, infection, malformations, or other types of renal damage. To enhance the management of paediatric cases involving renal malformations and to reduce the incidence of chronic and progressive kidney diseases in “future adults”, our study aims to identify and categorise various renal anomalies. Methods: This has been achieved by analysing the Tc-99m DMSA renal scans of a large cohort of 931 children diagnosed with different renal pathologies. After interpreting the scans, we categorised the renal malformations and cortical modifications into four groups: kidney number anomalies, positional anomalies, structural anomalies, and shape anomalies. Results: There has been a notable increase in the demand for renal scintigraphy in recent years, rising from 82 cases in 2019 to 183 cases in 2024. Structural anomalies were the most common type of malformations (73% from all patients), featuring a significant variety of cortical modifications. In total, 98 cases (93% from kidney number anomalies and 10.5% from all children) were diagnosed with renal agenesis. Additionally, 30 children (3.2% from all patients) had positional anomalies, primarily ectopic kidneys, and 54 patients (5.8% from all cases) had shape malformations, especially fused kidneys. Conclusions: Combining the Tc-99m DMSA renal scan with ultrasound provides a more reliable diagnosis of paediatric renal progressive diseases. A more accurate diagnosis allows for quicker treatment and prevention of potential complications, ultimately improving the quality of life and decreasing hospital costs of paediatric patients becoming adults.

Background: Pediatric idiopathic nephrotic syndrome (INS) is classified primarily by corticosteroid response, delaying identification of steroid-resistant disease and exposing children to unnecessary treatment toxicity. Novel biomarkers could enable earlier biological stratification and treatment guidance. Objectives: The study aimed to map available evidence on candidate biomarkers in pediatric INS published since 2020, with emphasis on anti-nephrin autoantibodies and their potential for clinical translation. Data Sources: PubMed/MEDLINE and Web of Science Core Collection (January 2020–October 2025), with a supplementary verification search in Scopus and Embase and manual reference screening. Eligibility Criteria: Original studies reporting circulating, urinary, or tissue-based biomarkers in children aged 0–18 years with idiopathic NS, with outcomes related to diagnosis, treatment response, relapse prediction, or monitoring. Studies in adults only, secondary NS, or animal models were excluded. Results: After screening, 34 studies met the eligibility criteria and were included, grouped into five categories: autoantibodies, urinary markers, immune cell signatures, cytokines/chemokines, and exploratory markers (metabolomics, extracellular vesicles, lipid profiles, microRNAs). Anti-nephrin IgG emerged as the most mechanistically informative marker, with seroprevalence declining across phenotypes (SSNS 68%, SDNS 28%, non-genetic SRNS 14%, genetic SRNS 2%) and positivity predicting response to intensified immunosuppression. Of the candidates reviewed, urinary NGAL and peripheral B-cell subset monitoring are the most readily implementable with existing laboratory infrastructure. Conclusions: Pediatric INS encompasses a spectrum of immune-mediated podocytopathies that may soon be distinguishable by emerging biomarker profiles. Anti-nephrin autoantibodies provide the strongest mechanistic evidence for an autoimmune podocytopathy.