Pediatric Malignancies Research Articles

Abstract 3566: Mohs surgery trends in 104 cases of pediatric melanoma

Abstract Background: Cutaneous melanoma is rare in children with a global incidence of two to five cases per million people per year, accounting for roughly 1% of all pediatric malignancies.5 However, the incidence of pediatric melanoma in the United States is increasing.1 Mohs Micrographic Surgery (MMS) is a standard treatment for adult skin cancer due to its low recurrence rates and tissue preservation. However, it is less commonly used to treat melanoma in children because the required infrastructure is not widely accessible and many pediatric surgeons are not familiar with MMS.4 With more limited treatment options for pediatric melanoma, it is important to question the role of socioeconomic factors that may contribute to MMS treatment of pediatric patients with melanoma.2 Purpose: The purpose of the study is to investigate pediatric patients with melanoma and assess their tumor characteristics by comparing various skin cancer treatments (Mohs, other treatments [local excision], or no treatment).Methods: This is a retrospective cohort study of pediatric patients (age < 21 years) diagnosed with cutaneous Melanoma who received MMS between 2004 and 2020 in the National Cancer Database (NCDB). Descriptive statistics were collected on the following variables: the year of diagnosis, sex, race, tumor stage, tumor behavior, primary site, and surgical procedure. Overall survival was determined via the Kaplan-Meier test. Results: 104 cases of pediatric melanoma treated with MMS were identified. Per statistical analysis, it does not appear that surgical frequency has varied yearly from 2004 to 2020 (r² = 0). The median age of patients analyzed was 18 years old. Most patients were female (64.4%, N = 67), White (100%, N=104), non-Hispanic (100%, N=104), and had private insurance (87.3%, N = 90). 70.2% (N=73) of cases were defined as early-stage (stage 0 or I). 72.1% (N=75) of cases were identified as invasive. 45.2% (N=47) of MMS were performed with a margin of 1 cm or less, 19.2% (N=20) were performed with a margin of 1 cm or more, and the remaining had unspecified margins. The most common primary site for MMS was skin of the trunk (33.7%, N=35), followed by the upper limb and shoulder (16.3%, N=17), and the lower limb and hip (15.4%, N=16). All patients were alive at the last contact, with a median overall survival of 182 months (15.2 years). Discussion: MMS is used commonly in adults to treat a variety of skin tumors that can have aggressive traits such as melanoma. Although it offers low recurrence rates and tissue-sparing treatment in adult populations, MMS frequency has not changed within the pediatric population. MMS is mainly seen in privately insured, White patients with an early stage of melanoma; this is likely due to lower rates and delayed diagnosis in patients with darker skin that would otherwise present with metastatic disease. Given its clinical advantages and low rate of use, further research should address barriers that affect the availability of MMS in the pediatric population. Citation Format: Zachary G. Brandt, Xinxin Wu, Jared Kennard, Julia Griffin, Peter Silberstein. Mohs surgery trends in 104 cases of pediatric melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3566.

Abstract 5121: Next-generation immunocompetent and humanized neuroblastoma murine models for the discovery and validation of novel immunotherapies

Abstract The success of CD19-directed chimeric antigen receptor (CAR)-T cell therapy for ALL has yet to be matched in solid pediatric malignancies. Moreover, immune checkpoint blockade has shown limited benefit in pediatric cancer. Despite this unmet need, there is a lack of reliable preclinical models to facilitate novel target discovery, validate therapeutic benefit, anticipate on- or off-target toxicity, and understand mechanisms of resistance. Syngeneic murine model systems are a critical intermediate for preclinical translation, preserving the complex and heterogenous immune landscape and host-immunotherapy interactions. However, model interpretation and validity are limited as expression and function of murine targets and immune effector cells are not always conserved. We have developed a syngeneic immunocompetent C57BL/6 neuroblastoma system to study CAR efficacy, toxicity, and mechanisms of resistance, as well a variety of vaccination strategies. Specifically, we have built two murine CAR T constructs containing a 100% conserved antigen-directed scFv joined to orthologous murine TCR signaling machinery. In parallel, we engineered the murine neuroblastoma cell line 9464D to stably express surface antigen Gpc2 (Bosse, Cancer Cell 2017), or a novel chimeric single chain trimer of a 9mer peptide from intracellular oncoprotein PHOX2B discovered on HLA-A*24:02 (Yarmarkovich, Nature 2023) as Phox2b/A24*02/H2-kb to generate tumor-bearing B6 or B6-A24-Tg mice. We are currently using this system to demonstrate how vaccination approaches enhance the persistence and potency of CART directed to both targets and are extending our syngeneic murine constructs to additional TH-MYCN allograft models. To further study the innate and adaptive immune response to various therapeutics, we have developed peripheral blood mononuclear cell (PBMC) humanized models. Our autologous humanized PDX mouse models of neuroblastoma use immunocompromised NSG mice engrafted with a PDX and humanized with patient-matched PBMCs to evaluate personalized vaccines in vivo. We have shown the ability to stably engraft both lymphoid and myeloid populations in various human cytokine transgenic NSG variants (i.e. SGM3, Flt3L), allowing for T/B cell and APC crosstalk, thus providing a robust means to study targeted interventions. We are currently using this autologously humanized PDX model to test the ability of multivalent, personalized neoantigen vaccines developed specific to the neoantigen landscape of individual PDXs, with a focus on endogenous T cell responses of patient PBMC against their own PDX in vivo. Citation Format: Timothy T. Spear, Elisabeth Posthill, David Groff, Anna M. Giudice, Kristopher R. Bosse, Leyuan Ma, Stephen P. Schoenberger, John M. Maris. Next-generation immunocompetent and humanized neuroblastoma murine models for the discovery and validation of novel immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5121.

Abstract 4907: RanBALL: Identifying B-cell acute lymphoblastic leukemia subtypes based on an ensemble random projection model

Abstract As the most common pediatric malignancy, B-cell acute lymphoblastic leukemia (B-ALL) has multiple distinct subtypes characterized by recurrent and sporadic somatic and germline genetic alterations like chromosomal alteration, transcription factor rearrangement or kinase inhibition. The treatment of B-ALL patients is personalized based on specific subtypes, as the treatment responses for different B-ALL subtypes may vary considerably. Identification of B-ALL subtypes can facilitate risk stratification and enable tailored therapeutic approaches. Existing methods for B-ALL subtyping primarily depend on immunophenotypic, cytogenetic and genomic analyses, which would be costly, complicated, and laborious in clinical practice applications. To overcome these challenges, we present RanBALL (an Ensemble Random Projection-Based Model for Identifying B-Cell Acute Lymphoblastic Leukemia Subtypes), an accurate and cost-effective model for B-ALL subtype identification based on transcriptomic profiling only. RanBALL leverages random projection (RP) to construct an ensemble of dimension-reduced multi-class classifiers for B-ALL subtyping. Specifically, the transcriptomic profiling features were projected onto low-dimensional spaces by random projection matrices whose elements conform to a distribution characterized by zero mean and unit variance. To ensure reliable and robust performance, we selected 20 subspace dimensions ranging from 600 to 2500, with intervals of 100. The transformed low dimensional data matrix was used for training an ensemble of multi-class support vector machine (SVM) classifiers, each corresponding to one of the RP matrices of various dimensions. The predicted probabilistic scores of each B-ALL subtype were integrated for determining the final decision. Results based on 10 times 10-fold cross validation tests for >1700 B-ALL patients demonstrated that the proposed model achieved an accuracy of 93.7%, indicating promising prediction capabilities of RanBALL for B-ALL subtyping. Furthermore, the 30% held-out tests suggested that the model was robust and consistent to maintain high confidence levels for accurate predictions. The high accuracies of RanBALL suggested that our model could effectively capture underlying patterns of transcriptomic profiling for accurate B-ALL subtype identification. To extend the impact of RanBALL, we have established a free and publicly available python package for RanBALL available at https://github.com/wan-mlab/RanBALL. We believe RanBALL will facilitate the discovery of B-ALL subtype-specific marker genes and therapeutic targets, and eventually have consequential positive impacts on downstream risk stratification and tailored treatment design. Citation Format: Lusheng Li, Hanyu Xiao, Joseph D. Khoury, Jieqiong Wang, Shibiao Wan. RanBALL: Identifying B-cell acute lymphoblastic leukemia subtypes based on an ensemble random projection model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4907.

Myeloid cells as potential targets for immunotherapy in pediatric gliomas.

Pediatric high-grade glioma (pHGG) including pediatric glioblastoma (pGBM) are highly aggressive pediatric central nervous system (CNS) malignancies. pGBM comprises approximately 3% of all pediatric CNS malignancies and has a 5-year survival rate of approximately 20%. Surgical resection and chemoradiation are often the standard of care for pGBM and pHGG, however, even with these interventions, survival for children diagnosed with pGBM and pHGG remains poor. Due to shortcomings associated with the standard of care, many efforts have been made to create novel immunotherapeutic approaches targeted to these malignancies. These efforts include the use of vaccines, cell-based therapies, and immune-checkpoint inhibitors. However, it is believed that in many pediatric glioma patients an immunosuppressive tumor microenvironment (TME) possess barriers that limit the efficacy of immune-based therapies. One of these barriers includes the presence of immunosuppressive myeloid cells. In this review we will discuss the various types of myeloid cells present in the glioma TME, including macrophages and microglia, myeloid-derived suppressor cells, and dendritic cells, as well as the specific mechanisms these cells can employ to enable immunosuppression. Finally, we will highlight therapeutic strategies targeted to these cells that are aimed at impeding myeloid-cell derived immunosuppression.

Pediatric Hodgkin Lymphoma Overview in Albania during the Last Decade

Background: Hodgkin lymphoma (HL) is a rare malignancy characterized by a malignant proliferation of cells in the reticuloendothelial system, mainly lymph node, and the presence of Reed-Sternberg cells with a relatively good prognosis compared to other pediatric malignancies. This study aimed to produce epidemiologic and clinical data on HL for Albania, aiming for a better understanding of the disease presentation to diagnose it at an earlier stage with the result of a better outcome. Methods and Results: This single-center, retrospective study performed in the Mother Theresa University Hospital Center (Tirana, Albania) analyzed epidemiological and clinical data of pediatric patients under 14 years of age diagnosed with HL during a 10-year study period from 2012 to 2022. During the last 10 years, 25 children (ages 0-14) were diagnosed with HL at UHC "Mother Theresa," Tirana. From the demographic data of our study, most patients (68%) were in the age group of 10-14. The male-to-female ratio was 2.12:1. The first clinical presentation was mainly because of lymphadenopathy in 92% of patients, with the presence of B symptoms in 68%.In most cases, the CBC was not affected, yet 24% of patients had high platelets, and 12% had low RBCs, while WBCs increased in 16% of patients and decreased in 12%.Lymphopenia and monocytosis were found in more than half of cases. Around 68% of patients had high levels of LDH and CRP. ESR and ALP were high in 64% of patients, Ferritin was high in 32%, and fibrinogen level was high in 28%.According to the Ann Arbor system, most of our patients were at stage II (32%), followed closely by stage I (28%) and stage III (24%), and only 16% were at stage IV upon presentation.The most common histopathologic type was nodular sclerosis classical HL, presented in 44% of cases. Conclusion: HL is a relatively frequent pediatric malignancy in young adults, affecting mainly males, and is diagnosed at a relatively early stage in our country.

Novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and aggressive presentation.

Childhood melanoma is a rare and biologically heterogeneous pediatric malignancy. The differential diagnosis of pediatric melanoma is usually broad, including a wide variety of spindle cell or epithelioid neoplasms. Different molecular alterations affecting the MAPK and PI3K/AKT/mTOR pathways, tumor suppressor genes, and telomerase reactivation have been implicated in melanoma tumorigenesis and progression. Here, we report a novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and an aggressive clinical course.

Anti-PD-1 Therapy in Advanced Pediatric Malignancies in Nationwide Study: Good Outcome in Skin Melanoma and Hodgkin Lymphoma.

The role of immune checkpoint inhibitors (ICIs; anti-PD1) in the treatment of childhood cancers is still evolving. The aim of this nationwide retrospective study was to assess the safety and effectiveness of ICIs used in a group of 42 patients, with a median age of 13.6 years, with various types of advanced malignancies treated in pediatric oncology centers in Poland between 2015 and 2023. The indications for treatment with anti-PD1 were as follows: Hodgkin lymphoma (11); malignant skin melanoma (9); neuroblastoma (8); and other malignancies (14). At the end of follow-up, complete remission (CR) was observed in 37.7% (15/42) of children and disease stabilization in 9.5% (4/42), with a mean survival 3.6 (95% CI = 2.6-4.6) years. The best survival (OS = 1.0) was observed in the group of patients with Hodgkin lymphoma. For malignant melanoma of the skin, neuroblastoma, and other rare malignancies, the estimated 3-year OS values were, respectively, 0.78, 0.33, and 0.25 (p = 0.002). The best progression-free survival value (0.78) was observed in the group with malignant melanoma. Significantly better effects of immunotherapy were confirmed in patients ≥ 14 years of age and good overall performance ECOG status. Severe adverse events were observed in 30.9% (13/42) patients.

Proliferative Effects of Mesenchymal Stromal Cells on Neuroblastoma Cell Lines: Are They Tumor Promoting or Tumor Inhibiting?

BackgroundNeuroblastoma is a common pediatric malignancy with poor survival for high-risk disease. Mesenchymal stromal cells (MSCs) have innate tumor-homing properties, enabling them to serve as a cellular delivery vehicle, but MSCs have demonstrated variable effects on tumor growth. We compared how placental MSCs (PMSCs) and bone marrow-derived MSCs (BM-MSCs) affect proliferation of neuroblastoma (NB) cells in vitro. MethodsIndirect co-culture assessed proliferative effects of 18 MSCs (early-gestation PMSCs (n = 9), term PMSCs (n = 5), BM-MSCs (n = 4) on three high-risk NB cell lines (NB1643, SH-SY5Y, and CHLA90). Controls were NB cells cultured in media alone. Proliferation was assessed using MTS assay and measured by fold change (fc) over controls. PMSCs were sub-grouped by neuroprotective effect: strong (n = 7), intermediate (n = 3), and weak (n = 4). The relationship between MSC type, PMSC neuroprotection, and PMSC gestational age on NB cell proliferation was assessed. ResultsNB cell proliferation varied between MSC groups. BM-MSCs demonstrated lower proliferative effects than PMSCs (fc 1.18 vs 1.44, p < 0.001). Neither gestational age nor neuroprotection significantly predicted degree of proliferation. Proliferative effects of MSCs varied among NB cell lines. BM-MSCs had less effect on CHLA90 (fc 1.01) compared to NB1643 (fc 1.33) and SH-SY5Y (fc 1.20). Only NB1643 showed a difference between early and term PMSCs (p = 0.04). ConclusionEffects of MSCs on NB cell proliferation vary by MSC source and NB cell line. BM-MSCs demonstrated lower proliferative effects than most PMSCs. MSC neuroprotection was not correlated with proliferation. Improved understanding of MSC proliferation-promoting mechanisms may provide valuable insight into selection of cells best suited as drug delivery vehicles. Level of EvidenceN/A. Type of StudyOriginal Research.

Prognostic Analysis of NLR, PLR, and, LMR in Osteosarcoma at Dr. Wahidin Sudirohusodo Hospital

Osteosarcoma is a primary pediatric bone malignancy with an annual incidence of 5.6 cases per million children under the age of 15. The high mortality rate leads to necessary for prognostic biomarkers of the disease. NLR, PLR, and LMR can be considered as prognostic predictors of osteosarcoma patients. This study aimed to determine the difference and correlation between NLR, PLR, and LMR based on grade and outcome in osteosarcoma patients. The study used medical record data from 122 osteosarcoma patients at Dr. Wahidin Sudirohusodo Hospital, Makassar. Samples were grouped by stage according to Enneking criteria (Grade I, II, and III) and by outcome (deceased and not deceased), then analyzed based on NLR, PLR, and LMR values using the Kruskal-Wallis test and the Mann-Whitney test (significant if p&lt;0.05). There was a significant difference in NLR, PLR, and LMR values by grade, (p=0.05). There was a significant difference in the value of NLR, and LMR based on output (p=0.00), but not in PLR (p=0.954). There was a correlation between the values of NLR, PLR, and LMR and the stage of osteosarcoma (p=0.05). Based on the outcome, a correlation with the NLR and LMR values was obtained (p=0.00), but there was no correlation with the PLR value (p=0.955). Cut-off NLR, PLR, and LMR were 4.43; 0.21; and 0.44, respectively, with sensitivity of 76%, 56%, and 76% and a specificity of 76%, 63.9%, and 68%, respectively. There were differences in NLR, PLR, and LMR values based on the stage and outcome of osteosarcoma. Higher NLR, PLR, and LMR values will lead to a higher stage of osteosarcoma and a worse outcome. Cut-off NLR, PLR, and LMR optimal for distinguishing stage of osteosarcoma were 4.43; 0.21, and 0.44, respectively.

Clinical Feature of Langerhans Cell Histiocytosis of the Orbit : A First Case Series in Indonesia

Introduction : Langer hans histiocytosis (LCH) is an inexplicable disease characterized by proliferation of Langerhans and intermixed with inflammatory cell, in particular eosinophil, which represents only 1% pediatric orbital tumours. Orbital involvement of LCH is a rare clinical entity as the disease simulate variety of malignancies and present as a diagnostic and management dilemma for ophthalmologist.&#x0D; Case Illustration : Two cases of toddler presented with unilateral progressive upper eyelid swelling and proptosis for more than a month. Both cases has history of orbital trauma 1 month before swelling was observed. Initial CT scan revealed extraconal mass, with destruction of lateral orbital wall and frontal bone. Both patients had histopathological biopsy confirmed eosinophlic cytoplasm. One patient confirmed immunohistochemistry markers S100 and CD1a which is specific for Langerhans cells. Both patients continue with chemotherapy as definitive treatment.&#x0D; Discussion : LCH is a wide clinical spectrum which manifestation simulate other pediatric orbital malignancies. Case illustration present unilateral eyelid swelling with history of trauma may resemble other diagnosis unless further work up is performed. This case series exhibits clinical manifestations that may be suggestive of LCH. Considering rapid progression of disease, definitive diagnosis is a mandatory based on histopatological analysis through biopsy surgery.&#x0D; Conclusion : LCH is rare disease, it should be considered as one of deferential diagnosis in pediatric orbital malignancy with initial presentation acute unilateral eyelid swelling, proptosis, history of trauma, extraconal mass and destruction of bones as radiological features. This might be helpful for early recognition and prompt treatment of disease suggestive of LCH.

Summary of biological research on hepatoblastoma: a scoping review.

Hepatoblastoma is the most prevalent primary hepatic malignancy in children, comprising 80% of pediatric hepatic malignancies and 1% of all pediatric malignancies. However, traditional treatments have proven inadequate in effectively curing hepatoblastoma, leading to a poor prognosis. A literature search was conducted on multiple electronic databases (PubMed and Google Scholar). A total of 86 articles were eligible for inclusion in this review. This review aims to consolidate recent developments in hepatoblastoma research, focusing on the latest advances in cancer-associated genomics, epigenetic studies, transcriptional programs and molecular subtypes. We also discuss the current treatment approaches and forthcoming strategies to address cancer-associated biological challenges. To provide a comprehensive summary of the molecular mechanisms associated with hepatoblastoma occurrence, this review highlights three key aspects: genomics, epigenetics, and transcriptomics. Our review aims to facilitate the exploration of novel molecular mechanisms and the development of innovative clinical treatment strategies for hepatoblastoma.

Contemporary preclinical mouse models for pediatric rhabdomyosarcoma: from bedside to bench to bedside.

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue malignancy, characterized by high clinicalopathological and molecular heterogeneity. Preclinical in vivo models are essential for advancing our understanding of RMS oncobiology and developing novel treatment strategies. However, the diversity of scholarly data on preclinical RMS studies may challenge scientists and clinicians. Hence, we performed a systematic literature survey of contemporary RMS mouse models to characterize their phenotypes and assess their translational relevance. We identified papers published between 01/07/2018 and 01/07/2023 by searching PubMed and Web of Science databases. Out of 713 records screened, 118 studies (26.9%) were included in the qualitative synthesis. Cell line-derived xenografts (CDX) were the most commonly utilized (n = 75, 63.6%), followed by patient-derived xenografts (PDX) and syngeneic models, each accounting for 11.9% (n = 14), and genetically engineered mouse models (GEMM) (n = 7, 5.9%). Combinations of different model categories were reported in 5.9% (n = 7) of studies. One study employed a virus-induced RMS model. Overall, 40.0% (n = 30) of the studies utilizing CDX models established alveolar RMS (aRMS), while 38.7% (n = 29) were embryonal phenotypes (eRMS). There were 20.0% (n = 15) of studies that involved a combination of both aRMS and eRMS subtypes. In one study (1.3%), the RMS phenotype was spindle cell/sclerosing. Subcutaneous xenografts (n = 66, 55.9%) were more frequently used compared to orthotopic models (n = 29, 24.6%). Notably, none of the employed cell lines were derived from primary untreated tumors. Only a minority of studies investigated disseminated RMS phenotypes (n = 16, 13.6%). The utilization areas of RMS models included testing drugs (n = 64, 54.2%), studying tumorigenesis (n = 56, 47.5%), tumor modeling (n = 19, 16.1%), imaging (n = 9, 7.6%), radiotherapy (n = 6, 5.1%), long-term effects related to radiotherapy (n = 3, 2.5%), and investigating biomarkers (n = 1, 0.8%). Notably, no preclinical studies focused on surgery. This up-to-date review highlights the need for mouse models with dissemination phenotypes and cell lines from primary untreated tumors. Furthermore, efforts should be directed towards underexplored areas such as surgery, radiotherapy, and biomarkers.

Ocular and orbital tumors in childhood

Pediatric tumors of the eye and orbit can be benign or malignant as well as congenital or acquired and are usually distinctively different than those seen in adults. Although most of these neoplasms are benign (eg, dermoid cyst, chalazion, molluscum), their location near and within a vital organ can result in serious dermatologic and ophthalmologic sequelae. Lesions discussed include vascular lesions, retinoblastomas (the most common primary pediatric intraocular malignancy), rhabdomyosarcoma (the most common primary pediatric orbital malignancy), Langerhans cell histiocytosis, and metastatic lesions to the orbit (neuroblastoma, Ewing sarcoma). Although cysts and ocular melanoma can occur within the pediatric population, these conditions are covered in other contributions in this issue of Clinics in Dermatology.

Steroid-Associated Adverse Events Are Dose-Dependent Following Hematopoietic Cell Transplantation for Pediatric Hematologic Malignancies

Steroid-Associated Adverse Events Are Dose-Dependent Following Hematopoietic Cell Transplantation for Pediatric Hematologic Malignancies

Reduced Healthcare Resource Utilization in TCR Αβ/CD19-Depleted Haploidentical Compared to Matched Related and Unrelated Donor Hematopoietic Cell Transplant in First 100 Days for Pediatric Hematologic Malignancies

Reduced Healthcare Resource Utilization in TCR Αβ/CD19-Depleted Haploidentical Compared to Matched Related and Unrelated Donor Hematopoietic Cell Transplant in First 100 Days for Pediatric Hematologic Malignancies

Total Splenectomy for Splenic Abscess in Pediatric Oncology: A Report of Two Cases

AbstractSplenic abscess is a relatively uncommon condition, especially in pediatric malignancies. The diagnosis of a splenic abscess is a clinical challenge due to low incidence. The condition is fatal if not diagnosed on time. We are reporting two cases with underlying immune suppression secondary to malignancy and multidrug-resistant sepsis with splenic abscesses as the focus. Both children had life-threatening sepsis and required total splenectomy as a life-saving measure. Postsplenectomy course was uneventful with clinical improvement, and chemotherapy was continued. High suspicion is necessary due to nonspecific presentation. The treatment of splenic abscess includes conservative management and percutaneous drainage. Splenectomy is generally not indicated; however, total splenectomy may be required in the setting of multiple splenic abscesses, also to prevent overwhelming infection in an immunocompromised setting.

Pretransplant malignancy in pediatrics is not a risk factor for renal graft failure.

In adults, pretransplant malignancy (PTM) negatively impacts patient survival due to immunosuppression regimens influencing post-transplantation tumor growth. Few reports investigate the outcomes of pediatric kidney transplantation with PTM. We compare transplant outcomes for pediatric patients with PTM to matched controls, including cancer types extending beyond Wilms tumor. The United Network of Organ Sharing Database was queried to identify pediatric transplant recipients with histories of PTM. All PTM patients were matched to non-PTM patients, at a 1:1 ratio, with 0.001 match tolerance. Matching variables included transplant year, recipient age, recipient gender, recipient race, donor type, and prior transplant. Death-censored graft and patient survival were analyzed. All statistics were reported with 95% confidence intervals (CI). After propensity matching, 285 PTM and 285 non-PTM patients were identified, with transplant dates from 1990 to 2020. Median Kidney Donor Profile Index values were comparable between cohorts, 17% and 12%, respectively (p = .065). Kaplan-Meier analysis revealed that PTM patients did not have a significantly different rate of death-censored graft failure, compared to the non-PTM group [HR 0.76; 95% CI (0.54-1.1)]. There was also no difference in the overall survival between the two groups of patients [HR 1.1; 95% CI (0.66-2.0)]. A history of pediatric malignancy has minimal independent effect on their post-transplant survival. Additionally, pediatric patients with PTM demonstrated equivalent rates of graft survival. Thus, in contrast to adults, renal failure in children with history of pediatric malignancies should not be considered a complicating factor for renal transplantation.

Survival Trends in Pediatric Differentiated Thyroid Cancer: A Middle Eastern Perspective.

Pediatric Differentiated Thyroid Cancer (pedDTC) is a rare pediatric malignancy with an increasing incidence over time. To date, there is a paucity of literature specifically addressing pedDTC within the context of Middle Eastern ethnicity. This retrospective study aimed to assess the risk-stratifying factors for overall survival (OS) and event-free survival (EFS) in pediatric DTC patients from Iraq and Jordan. The medical records of 81 patients from two tertiary cancer institutes were retrieved. Kaplan-Meier analysis was employed to investigate OS and EFS, and the Cox proportional hazards model was employed to estimate hazard ratios. All patients underwent surgery and radioactive iodine therapy, with a median age of 14 and an interquartile range of 12-15. Lymph node involvement was observed in 55% of cases, while distant metastases were present in 13.5%. After a median follow-up period of 68 months, the 10-year survival rate was determined to be 94%, while the 10-year EFS rate was 58%. EFS was negatively impacted by cervical lymph node metastases and early age of diagnosis (p ≤ 0.01, each). Therefore, pediatrics with initial cervical lymph node metastases and those diagnosed before puberty tend to experience poorer EFS, which may justify the need for more aggressive management plans.

Positron emission tomography in the diagnosis and management of primary pediatric lung tumors.

Primary pediatric lung tumors are uncommon and have many overlapping clinical and imaging features. In contrast to adult lung tumors, these rare pediatric neoplasms have a relatively broad histologic spectrum. Informed by a single-institution 13-year retrospective record review, we present an overview of the most common primary pediatric lung neoplasms, with a focus on the role of positron emission tomography (PET), specifically 18F-fluorodeoxyglucose (FDG) PET and 68Ga-DOTATATE PET, in the management of primary pediatric lung tumors. In addition to characteristic conventional radiographic and cross-sectional imaging findings, knowledge of patient age, underlying cancer predisposition syndromes, and PET imaging features may help narrow the differential. While metastases from other primary malignancies remain the most commonly encountered pediatric lung malignancy, the examples presented in this pictorial essay highlight many of the important conventional radiologic and PET imaging features of primary pediatric lung malignancies.

Epidemiology of pediatric hematological malignancies in Kazakhstan: Data from Unified National Electronic Healthcare System 2014-2021.

Patients with ALL had a higher incidence rate than patients with AML. The incidence rate of HL and NHL was relatively similar. All-cause mortality rates for leukemia and lymphomas were quite stable during the study period. Younger age is significantly associated with increased all-cause mortality among AML patients. However, there is no significant association of age with all-cause mortality among ALL, HL and NHL. In order to obtain more reliable data and analysis on pediatric (hematological) malignancies, specific registries for childhood tumors (including detailed information on relapses, treatments, short and long-term side effects, and specific death causes) should be implemented. • Leukemias and lymphomas together account for around 45% of all pediatric malignancies. • Lymphoma accounts for 12% of all childhood malignancies; non-Hodgkin's lymphomas (NHL) are more frequent than Hodgkin's lymphomas (HL). • The incidence rate of ALL was higher than the incidence rate of AML throughout the whole study period, whereas all-cause mortality of ALL and AML was quite stable. • According to Cox PH analysis, younger age (0-5years old) was associated with a higher risk of death among AML children compared to older children, and no significant association of age was observed with all-cause mortality among ALL and lymphomas.