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Fundoscopy is the standard method for diagnosis and follow-up of intraocular retinoblastoma, but it is sometimes insufficient to discern whether tumors are inactivated following treatments. In this work, we hypothesized that the amount of conserved nuclear DNA sequences in the cell-free DNA (cfDNA) fraction of the aqueous humor (AH) might complement fundoscopy for retinoblastoma follow-up. To address our hypothesis, we developed highly sensitive droplet digital polymerase chain reaction (ddPCR) methods to quantify highly conserved DNA sequences of nucleus-encoded genes (GAPDH and B4GALNT1) and of a mitochondrial gene, MT-ATP6. We obtained AH samples during intravitreal treatments. We analyzed 42 AH samples from 25 patients with intraocular retinoblastoma and 11 AH from controls (non-cancer patients). According to clinical criteria, we grouped patients as having progression-free or progressive retinoblastoma. cfDNA concentration in the AH was similar in both retinoblastoma groups. Copy counts for nucleus-derived sequences of GAPDH and B4GALNT1 were significantly higher in the AH from patients with progressive disease, compared to the AH from progression-free patients and control non-cancer patients. The presence of mitochondrial DNA in the AH explained that both retinoblastoma groups had similar cfDNA concentration in AH. The optimal cut-off point for discriminating between progressive and progression-free retinoblastomas was 108 GAPDH copies per reaction. Among patients having serial AH samples analyzed during their intravitreal chemotherapy, GAPDH copies were high and decreased below the cut-off point in those patients responding to chemotherapy. In contrast, one non-responder patient remained with values above the cut-off during follow-up, until enucleation. We conclude that the measurement of conserved nuclear gene sequences in AH allows follow-up of intraocular retinoblastoma during intravitreal treatment. The method is applicable to all patients and could be relevant for those in which fundoscopy evaluation is inconclusive.

Aim: This article describes a peripheral oral giant cell granuloma (POGCG) in a pediatric patient and its surgical management and histological characteristics. Background: Peripheral oral giant cell granuloma (POGCG) is a hyperplastic reactive lesion formed by a proliferation of mononuclear cells and osteoclast-type giant cells in vascular tissue, occasionally with bone formation. Generally found in women and adults, POGCG has rarely been described in children. Case description: An 8-year-old girl was consulted for an exophytic lesion in the anterior area of the upper jaw, which had increased in volume in the preceding weeks. An excisional biopsy of the tumor was performed with an electrosurgical pencil. The pathological diagnosis was POGCG. Conclusion: Excision followed by additional therapy, such as scaling and curettage, should be the first option in the treatment of POGCG. Clinical significance: Early detection of these lesions involving the periodontium is important in order to reduce bone loss and avoid pathological dental migration.

This file contains supplementary methods, supplementary references, supplementary figures S1-S6, supplementary tables S1, S3-S6, S8-S15, and S17, and legends for all supplementary figures and tables. Supplementary Figure S1. Summary of Ewing sarcoma tumor and cell line cohorts. Supplementary Figure S2. RNASeq validation of mutations identified by WES and WGS. Supplementary Figure S3. Power calculations for the detection of significantly mutated genes. Supplementary Figure S4. Copy number variants in Ewing sarcoma tumors. Supplementary Figure S5. ETS1 deletions associated with EWS/FLI rearrangements. Supplementary Figure S6. Copy number variants in diagnostic vs. treated Ewing sarcoma tumors. Supplementary Figure S7. SCNAs in paired Ewing sarcoma tumor samples. Supplementary Table S1. Tissue samples. Supplementary Table S3. Multiply mutated genes. Supplementary Table S4. Rearrangements and fusions detected by WGS and RNASeq. Supplementary Table S5. Mutational significance for tumor/normal pairs. Supplementary Table S6. Rate of coding mutations in Ewing sarcoma tumors. Supplementary Table S8. Mutational significance for all tumors. Supplementary Table S9. Gene set enrichment analyses of mutated genes. Supplementary Table S10. Significance of arm-level SCNAs. Supplementary Table S11. Multiply mutated genes of interest in all sample cohorts. Supplementary Table S12. Immunohistochemical staining of STAG2 in Ewing sarcoma tumors. Supplementary Table S13. Gene set enrichment analyses of STAG2 expressing vs. STAG2 loss. Supplementary Table S14. Gene and gene-fragment RPKM Values for EWS and ETS genes. Supplementary Table S15. ETS1 copy-number changes. Supplementary Table S17. Gene set enrichment analyses of tumors vs. cell lines.

Variants identified from WES of 92 tumors after filtering.

Pediatric Ewing sarcoma is characterized by the expression of chimeric fusions of EWS and ETS family transcription factors, representing a paradigm for studying cancers driven by transcription factor rearrangements. In this study, we describe the somatic landscape of pediatric Ewing sarcoma. These tumors are among the most genetically normal cancers characterized to date, with only EWS–ETS rearrangements identified in the majority of tumors. STAG2 loss, however, is present in more than 15% of Ewing sarcoma tumors; occurs by point mutation, rearrangement, and likely nongenetic mechanisms; and is associated with disease dissemination. Perhaps the most striking finding is the paucity of mutations in immediately targetable signal transduction pathways, highlighting the need for new therapeutic approaches to target EWS–ETS fusions in this disease.Significance: We performed next-generation sequencing of Ewing sarcoma, a pediatric cancer involving bone, characterized by expression of EWS–ETS fusions. We found remarkably few mutations. However, we discovered that loss of STAG2 expression occurs in 15% of tumors and is associated with metastatic disease, suggesting a potential genetic vulnerability in Ewing sarcoma. Cancer Discov; 4(11); 1326–41. ©2014 AACR.This article is highlighted in the In This Issue feature, p. 1243

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Supplementary Table 1 SampleSheet Supplementary Table 2 GEO_IDs Supplementary Table 3 EpiWNT-SHH_data Supplementary Table 4 EpiWNT-SHH_test Supplementary Table 5 EpiG3-G4_data Supplementary Table 6 EpiG3-G4_test

Purpose: Neuroblastoma is an embryonal tumor with contrasting clinical courses. Despite elaborate stratification strategies, precise clinical risk assessment still remains a challenge. The purpose of this study was to develop a PCR-based predictor model to improve clinical risk assessment of patients with neuroblastoma.Experimental Design: The model was developed using real-time PCR gene expression data from 96 samples and tested on separate expression data sets obtained from real-time PCR and microarray studies comprising 362 patients.Results: On the basis of our prior study of differentially expressed genes in favorable and unfavorable neuroblastoma subgroups, we identified three genes, CHD5, PAFAH1B1, and NME1, strongly associated with patient outcome. The expression pattern of these genes was used to develop a PCR-based single-score predictor model. The model discriminated patients into two groups with significantly different clinical outcome [set 1: 5-year overall survival (OS): 0.93 ± 0.03 vs. 0.53 ± 0.06, 5-year event-free survival (EFS): 0.85 ± 0.04 vs. 0.042 ± 0.06, both P < 0.001; set 2 OS: 0.97 ± 0.02 vs. 0.61 ± 0.1, P = 0.005, EFS: 0.91 ± 0.8 vs. 0.56 ± 0.1, P = 0.005; and set 3 OS: 0.99 ± 0.01 vs. 0.56 ± 0.06, EFS: 0.96 ± 0.02 vs. 0.43 ± 0.05, both P < 0.001]. Multivariate analysis showed that the model was an independent marker for survival (P < 0.001, for all). In comparison with accepted risk stratification systems, the model robustly classified patients in the total cohort and in different clinically relevant risk subgroups.Conclusion: We propose for the first time in neuroblastoma, a technically simple PCR-based predictor model that could help refine current risk stratification systems. Clin Cancer Res; 18(7); 2012–23. ©2012 AACR.

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Supplementary Methods Supplementary Figure 1 Unsupervised DNA methylation analysis of the training cohort. Supplementary Figure 2 Comparison between the Illumina Infinium Human Methylation450K BeadChip and the Methylation EPIC BeadChip 850K array platforms. Supplementary Figure 3 Specificity of the epigenetic biomarkers for medulloblastoma subgroups. Supplementary Figure 4 Assay performance for low-input titration series. Supplementary Figure 5 Validation of the epigenetic classifier Panel EpiWNT-SHH using DNA methylation microarray data of medulloblastoma samples. Supplementary Figure 6 Validation of the methylation pattern of Panel EpiWNT-SHH using pyrosequencing and direct bisulfite sequencing. Supplementary Figure 7 Schematic overview of the experimental strategy applied for identification of the epigenetic biomarkers and the development of the classifier EpiG3-G4. Supplementary Figure 8 Validation of the epigenetic classifier Panel EpiG3-G4 using DNA methylation microarray data.

Purpose: The classification of medulloblastoma into WNT, SHH, group 3, and group 4 subgroups has become of critical importance for patient risk stratification and subgroup-tailored clinical trials. Here, we aimed to develop a simplified, clinically applicable classification approach that can be implemented in the majority of centers treating patients with medulloblastoma.Experimental Design: We analyzed 1,577 samples comprising previously published DNA methylation microarray data (913 medulloblastomas, 457 non-medulloblastoma tumors, 85 normal tissues), and 122 frozen and formalin-fixed paraffin-embedded medulloblastoma samples. Biomarkers were identified applying stringent selection filters and Linear Discriminant Analysis (LDA) method, and validated using DNA methylation microarray data, bisulfite pyrosequencing, and direct-bisulfite sequencing.Results: Using a LDA-based approach, we developed and validated a prediction method (EpiWNT-SHH classifier) based on six epigenetic biomarkers that allowed for rapid classification of medulloblastoma into the clinically relevant subgroups WNT, SHH, and non-WNT/non-SHH with excellent concordance (>99%) with current gold-standard methods, DNA methylation microarray, and gene signature profiling analysis. The EpiWNT-SHH classifier showed high prediction capacity using both frozen and formalin-fixed material, as well as diverse DNA methylation detection methods. Similarly, we developed a classifier specific for group 3 and group 4 tumors, based on five biomarkers (EpiG3-G4) with good discriminatory capacity, allowing for correct assignment of more than 92% of tumors. EpiWNT-SHH and EpiG3-G4 methylation profiles remained stable across tumor primary, metastasis, and relapse samples.Conclusions: The EpiWNT-SHH and EpiG3-G4 classifiers represent a new simplified approach for accurate, rapid, and cost-effective molecular classification of single medulloblastoma DNA samples, using clinically applicable DNA methylation detection methods. Clin Cancer Res; 24(6); 1355–63. ©2018 AACR.

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycoprotein overexpressed by several cancers. Because SPARC shows high binding affinity to albumin, we reasoned that pediatric sarcoma xenografts expressing SPARC would show enhanced uptake and accumulation of nanoparticle albumin-bound (nab)-paclitaxel, a potent anticancer drug formulation. We first evaluated the expression of SPARC in patient-derived xenografts (PDXs) of Ewing sarcoma, rhabdomyosarcoma and osteosarcoma, finding variable SPARC gene expression that correlated well with SPARC protein measured by immunoblotting. We revealed that the activity of the fusion gene chimera EWSR1-FLI1, the genetic driver of Ewing sarcoma, leads to lower expression of the gene SPARC in these tumors, likely due to enriched acetylation marks of the histone H3 lysine 27 at regions including the SPARC promoter and potential enhancers. Then, we used SPARC-edited Ewing sarcoma cells (A673 line) to demonstrate that SPARC knocked down (KD) cells accumulated significantly less amount of nab-paclitaxel in vitro than SPARC wild type (WT) cells. In vivo, SPARC KD and SPARC WT subcutaneous xenografts in mice achieved similar maximum intratumoral concentrations of nab-paclitaxel, though drug clearance from SPARC WT tumors was significantly slower. We confirmed such SPARC-mediated long-term intratumoral accumulation of nab-paclitaxel in Ewing sarcoma PDX with high expression of SPARC, which accumulated significantly more nab-paclitaxel than SPARC-low PDX. SPARC-high PDX responded better to nab-paclitaxel than SPARC-low tumors, although these results should be taken cautiously, given that the PDXs were established from different patients that could have specific determinants predisposing response to paclitaxel. In addition, SPARC KD Ewing sarcoma xenografts responded better to soluble docetaxel and paclitaxel than to nab-paclitaxel, while SPARC WT ones showed similar response to soluble and albumin-carried drugs. Overall, our results show that pediatric sarcomas expressing SPARC accumulate nab-paclitaxel for longer periods of time, which could have clinical implications for chemotherapy efficacy., AMC acknowledges funding from AECC Scientific Foundation, MINECO (SAF2011-22660), European Union Seventh Framework Programme (FP7/2007-2013) under Marie Curie International Reintegration Grant (PIRG-08-GA-2010-276998) and ISCIII-FEDER (CP13/00189 and CPII18/00009). EDA, OMT and JM acknowledge support of AECC Scientific Foundation (GCB13131578). NU acknowledges funding by the Basque Government, Research Groups of the Basque University System (Project No. IT 1186-19). We thank support of the Central Service of Analysis in Alava, SGIker (UPV/EHU/ERDF, EU) and Xarxa de Bancs de Tumors de Catalunya (XBTC) sponsored by Pla Director d'Oncologia de Catalunya.

Ependymomas encompass a heterogeneous group of central nervous system (CNS) neoplasms that occur along the entire neuroaxis. In recent years, extensive (epi-)genomic profiling efforts have identified several molecular groups of ependymoma that are characterized by distinct molecular alterations and/or patterns. Based on unsupervised visualization of a large cohort of genome-wide DNA methylation data, we identified a highly distinct group of pediatric-type tumors (n = 40) forming a cluster separate from all established CNS tumor types, of which a high proportion were histopathologically diagnosed as ependymoma. RNA sequencing revealed recurrent fusions involving the pleomorphic adenoma gene-like 1 (PLAGL1) gene in 19 of 20 of the samples analyzed, with the most common fusion being EWSR1:PLAGL1 (n = 13). Five tumors showed a PLAGL1:FOXO1 fusion and one a PLAGL1:EP300 fusion. High transcript levels of PLAGL1 were noted in these tumors, with concurrent overexpression of the imprinted genes H19 and IGF2, which are regulated by PLAGL1. Histopathological review of cases with sufficient material (n = 16) demonstrated a broad morphological spectrum of tumors with predominant ependymoma-like features. Immunohistochemically, tumors were GFAP positive and OLIG2- and SOX10 negative. In 3/16 of the cases, a dot-like positivity for EMA was detected. All tumors in our series were located in the supratentorial compartment. Median age of the patients at the time of diagnosis was 6.2 years. Median progression-free survival was 35 months (for 11 patients with data available). In summary, our findings suggest the existence of a novel group of supratentorial neuroepithelial tumors that are characterized by recurrent PLAGL1 fusions and enriched for pediatric patients.

The omphalomesenteric duct is an embryologic structure that connects the yolk sac with the primitive midgut of the developing fetus. Omphalomesenteric duct anomalies include a group of entities that result from failed resorption of the omphalomesenteric duct. These anomalies include Meckel diverticulum, omphalomesenteric fistula, fibrous bands, cysts, and umbilical polyps. Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract and is usually asymptomatic. Symptoms develop when Meckel diverticulum involves complications such as hemorrhage, inflammation, and perforation, or when it causes intussusception or bowel obstruction. Hemorrhage is the most common complication of Meckel diverticulum, and technetium 99m-pertechnetate scintigraphy is the imaging modality of choice for detecting acute bleeding. US and CT are commonly used for the evaluation of patients with other complications such as obstruction and inflammation. Nevertheless, the diagnosis of these complications can be challenging, as their clinical manifestations are usually nonspecific and can masquerade as other acute intraabdominal entities such as appendicitis, inflammatory bowel disease, or other causes of bowel obstruction. There are other umbilical disorders, such as urachal remnants and umbilical granuloma, that may present with symptoms and imaging findings similar to those of omphalomesenteric duct anomalies. An accurate preoperative diagnosis of omphalomesenteric duct anomaly is crucial for appropriate management and a better outcome, particularly when these anomalies manifest as a life-threatening condition. The authors review the anatomy, clinical features, and complications of omphalomesenteric duct anomalies in children, describing the relevant differential diagnoses and associated imaging findings seen with different imaging modalities. ©RSNA, 2021.

Background The bone marrow (BM) is the most common site of dissemination in patients with aggressive, metastatic neuroblastoma (NB). However, the molecular mechanisms underlying the aggressive behavior of NB cells in the BM niche are still greatly unknown. In the present study, we explored biological mechanisms that play a critical role in NB cell survival and progression in the BM and investigated potential therapeutic targets. Methods Patient-derived bone marrow (BM) primary cultures were generated using fresh BM aspirates obtained from NB patients. NB cell lines were cultured in the presence of BM conditioned media containing cell-secreted factors, and under low oxygen levels (1% O2) to mimic specific features of the BM microenvironment of high-risk NB patients. The BM niche was explored using cytokine profiling assays, cell migration-invasion and viability assays, flow cytometry and analysis of RNA-sequencing data. Selective pharmacological inhibition of factors identified as potential mediators of NB progression within the BM niche was performed in vitro and in vivo. Results We identified macrophage migration inhibitory factor (MIF) as a key inflammatory cytokine involved in BM infiltration. Cytokine profiling and RNA-sequencing data analysis revealed NB cells as the main source of MIF in the BM, suggesting a potential role of MIF in tumor invasion. Exposure of NB cells to BM-conditions increased NB cell-surface expression of the MIF receptor CXCR4, which was associated with increased cell viability, enhanced migration-invasion, and activation of PI3K/AKT and MAPK/ERK signaling pathways. Moreover, subcutaneous co-injection of NB and BM cells enhanced tumor engraftment in mice. MIF inhibition with 4-IPP impaired in vitro NB aggressiveness, and improved drug response while delayed NB growth, improving survival of the NB xenograft model. Conclusions Our findings suggest that BM infiltration by NB cells may be mediated, in part, by MIF-CXCR4 signaling. We demonstrate the antitumor efficacy of MIF targeting in vitro and in vivo that could represent a novel therapeutic target for patients with disseminated high-risk NB.

Pediatric low-grade gliomas are the most frequent brain tumors in children. The standard approach for symptomatic unresectable tumors is chemotherapy. Recently, key molecular alterations/pathways have been identified and targeted drugs developed and tested in clinical trials. We describe our institutional experience with MAPK pathway targeted therapy. We retrospectively reviewed the medical reports of 23 patients diagnosed with PLGG and treated with either trametinib or dabrafenib at Hospital Sant Joan de Deu (Barcelona, Spain). Patients with neurofibromatosis were excluded. Objective response rate (ORR) and disease control rate (DCR) were determined using the Response Assessment in Pediatric Neuro-Oncology criteria in low-grade glioma. ORR was defined as the proportion of patients with the best overall response including complete remission (CR) or partial remission (PR). DCR was the sum of the CR, PR, and stable disease (SD) rates. ORR with trametinib was 0% (95% CI, 0%–23.2%) and DCR was 78.6% (95% CI, 49.2%–95.3%). Eleven patients had SD and three patients presented PD. ORR with dabrafenib was 41.7% (95% CI, 16.5%–71.4%), including four CR and one patient with PR. DCR with dabrafenib was 100% (95% CI, 73.5%–100%); there were seven SD and none PD. Treatment was well tolerated. Only three patients, on trametinib, presented grade 3 adverse effects: leukocytoclastic vasculitis, cheilitis, and bone infection. Our experience adds to the growing data about the efficacy and tolerability of targeted therapy in patients with PLGG. When present, toxicity is mainly mild-moderate and transient. Ongoing prospective clinical trials are trying to address if its use should be advanced to first-line therapy.

Pediatric large B-cell lymphomas (LBCLs) share morphological and phenotypic features with adult types but have better prognosis. The higher frequency of some subtypes such as LBCL with IRF4 rearrangement (LBCL-IRF4) in children suggests that some age-related biological differences may exist. To characterize the genetic and molecular heterogeneity of these tumors, we studied 31 diffuse LBCLs (DLBCLs), not otherwise specified (NOS); 20 LBCL-IRF4 cases; and 12 cases of high-grade B-cell lymphoma (HGBCL), NOS in patients ≤25 years using an integrated approach, including targeted gene sequencing, copy-number arrays, and gene expression profiling. Each subgroup displayed different molecular profiles. LBCL-IRF4 had frequent mutations in IRF4 and NF-κB pathway genes (CARD11, CD79B, and MYD88), losses of 17p13 and gains of chromosome 7, 11q12.3-q25, whereas DLBCL, NOS was predominantly of germinal center B-cell (GCB) subtype and carried gene mutations similar to the adult counterpart (eg, SOCS1 and KMT2D), gains of 2p16/REL, and losses of 19p13/CD70. A subset of HGBCL, NOS displayed recurrent alterations of Burkitt lymphoma–related genes such as MYC, ID3, and DDX3X and homozygous deletions of 9p21/CDKN2A, whereas other cases were genetically closer to GCB DLBCL. Factors related to unfavorable outcome were age >18 years; activated B-cell (ABC) DLBCL profile, HGBCL, NOS, high genetic complexity, 1q21-q44 gains, 2p16/REL gains/amplifications, 19p13/CD70 homozygous deletions, and TP53 and MYC mutations. In conclusion, these findings further unravel the molecular heterogeneity of pediatric and young adult LBCL, improve the classification of this group of tumors, and provide new parameters for risk stratification.

The microenvironment of retinoblastoma, the solid malignancy of the developing retina, is immunosuppressive. To study the interactions between tumor-associated microglia/macrophages (TAMs) and tumor cells in retinoblastomas, we analyzed immunohistochemistry markers in 23 patient samples and characterized 105 secreted cytokines of 11 retinoblastoma cell models in culture. We detected profuse infiltration of CD163(+) protumoral M2-like polarized TAMs in eyes enucleated due to cancer progression. Previous treatment of patients increased the number of TAMs but did not affect M2-like polarization. M2-like microglia/macrophages were almost absent in five eyes obtained from children enucleated due to nontumoral causes. CD8(+) tumor-infiltrating lymphocytes (TILs) were moderately abundant in tumor eyes and very scarce in nontumoral ones. The expression of the immune checkpoint molecule PD-L1 was absent in 95% of the tumor samples, which is concordant with the finding of FOXP3(+) Tregs infiltrating tumors. We confirmed the pathology results using single-cell transcriptome analysis of one tumor. We identified the cytokines extracellular matrix metalloproteinase inducer (EMMPRIN) and macrophage migration inhibitory factor (MIF), both with reported immunosuppressive activity, secreted at high levels in retinoblastoma primary cell cultures. Gene expression analysis of a large retinoblastoma cohort and single-cell transcriptome analysis confirmed that MIF and EMMPRIN were significantly upregulated in retinoblastomas, which led us to quantify both proteins by immunoassays in liquid biopsies (aqueous humor obtained from more than 20 retinoblastoma patients). We found a significant increase in the concentration of MIF and EMMPRIN in cancer patients, compared to 12 noncancer ones. Finally, we showed that macrophages derived from peripheral blood mononuclear cells increased the expression of markers of M2-like polarization upon exposure to retinoblastoma-conditioned medium or recombinant MIF. Overall, our findings suggest that retinoblastoma cell secretions induce the protumoral phenotype of this tumor. Our results might have clinical impact in the fields of biomarkers and treatment. © 2022 The Pathological Society of Great Britain and Ireland.

Retinoblastoma is the most frequent intraocular malignancy in children, originating from a maturing cone precursor in the developing retina. Little is known on the molecular basis underlying the biological and clinical behavior of this cancer. Here, using multi-omics data, we demonstrate the existence of two retinoblastoma subtypes. Subtype 1, of earlier onset, includes most of the heritable forms. It harbors few genetic alterations other than the initiating RB1 inactivation and corresponds to differentiated tumors expressing mature cone markers. By contrast, subtype 2 tumors harbor frequent recurrent genetic alterations including MYCN-amplification. They express markers of less differentiated cone together with neuronal/ganglion cell markers with marked inter- and intra-tumor heterogeneity. The cone dedifferentiation in subtype 2 is associated with stemness features including low immune and interferon response, E2F and MYC/MYCN activation and a higher propensity for metastasis. The recognition of these two subtypes, one maintaining a cone-differentiated state, and the other, more aggressive, associated with cone dedifferentiation and expression of neuronal markers, opens up important biological and clinical perspectives for retinoblastomas., Retinoblastoma is the most frequent intraocular paediatric malignancy whose molecular basis remains poorly understood. Here, the authors perform multi-omic analysis and identify two subtypes; one in a cone differentiated state and one more aggressive showing cone dedifferentiation and expressing neuronal markers.

PURPOSE: Pediatric low-grade gliomas (PLGG) have excellent overall survival but frequently need non-surgical therapy at diagnosis or after progression at unresectable sites such as the optic pathway. Chemotherapy side effects have led to the need for better-tolerated regimens with a sustained response. Bevacizumab, a humanized anti-VEGF monoclonal antibody has been used in monotherapy and/or in combination for these entities. Here we present our experience with its use in PLGG. METHODS: A retrospective, observational, single-institution study between 2008-2018 was performed, reporting the short-term outcomes of safety and efficacy of bevacizumab in progressive PLGG. RESULTS: Twenty-six patients with a median age at diagnosis of 3.32 years old [0.12-14.7] and the median age at the treatment of 8.11 years old [0.41-16.82] were included in the study. Nineteen had optic pathway gliomas and chiasmatic-hypothalamic gliomas (73.1%), 9 of them (47.4%) associated with neurofibromatosis type 1 (NF1). Fourteen non-NF1 tumors were molecularly studied, disclosing BRAF-KIAA1549 fusion transcript in 9 and BRAF V600E mutation in 2. Bevacizumab was administered in combination with other agent(s) in 16 of the 35 treatment courses. Responses were assessed at 3, 6, 12 months, and at the end of treatment. Progression-free survival at 12 months was 94%, and no severe adverse events were observed. CONCLUSIONS: In our series, Bevacizumab in PLGG showed short-term clinical efficacy with a favorable toxicity profile. Larger and long-term prospective studies may determine whether the response is conditioned upon different clinical or molecular features.

Ependymomas encompass a heterogeneous group of central nervous system (CNS) neoplasms that occur along the entire neuroaxis. In recent years, extensive (epi-)genomic profiling efforts have identified several molecular groups of ependymoma that are characterized by distinct molecular alterations and/or patterns. Based on unsupervised visualization of a large cohort of genome-wide DNA methylation data, we identified a highly distinct group of pediatric-type tumors (n = 40) forming a cluster separate from all established CNS tumor types, of which a high proportion were histopathologically diagnosed as ependymoma. RNA sequencing revealed recurrent fusions involving the pleomorphic adenoma gene-like 1 (PLAGL1) gene in 19 of 20 of the samples analyzed, with the most common fusion being EWSR1:PLAGL1 (n = 13). Five tumors showed a PLAGL1:FOXO1 fusion and one a PLAGL1:EP300 fusion. High transcript levels of PLAGL1 were noted in these tumors, with concurrent overexpression of the imprinted genes H19 and IGF2, which are regulated by PLAGL1. Histopathological review of cases with sufficient material (n = 16) demonstrated a broad morphological spectrum of largely ependymoma-like tumors. Immunohistochemically, tumors were GFAP-positive and OLIG2- and SOX10-negative. In 3/16 of the cases, a dot-like positivity for EMA was detected. Consistent with other fusion-positive ependymal groups, all tumors in our series were located in the supratentorial compartment. Median age of the patients at the time of diagnosis was 6.2 years. Analysis of time to progression or recurrence revealed survival times comparable to those of patients with ZFTA:RELA-fused ependymoma. In summary, our findings suggest the existence of a novel group of supratentorial ependymomas that are characterized by recurrent PLAGL1 fusions and enriched for pediatric patients.

Desmosomal genodermatoses are a heterogeneous group of in-herited diseases caused by defective desmosomal components. Ectodermal dysplasia-skin fragility syndrome (ED-SF syndro-me) is an infrequent autosomal recessive disorder caused by mutations in the PKP1 gene encoding plakophilin 1

Background Li-Fraumeni Syndrome (LFS) is a cancer predisposition syndrome characterized by the early-onset of multiple primary cancers which can occur at different moments (metachronous onset) or, more rarely, coincidentally (synchronous onset). Here we describe a previously unreported patient with presentation of synchronous Wilms tumor and Choroid plexus papilloma, leading to the diagnosis of a Li-Fraumeni Syndrome (LFS). Case presentation A 6-year-old girl without previous complains presented with abdominal pain. Abdominal US and MRI showed a left renal tumor with subcapsular hematoma. Due to mild headaches, the diagnostic workup included a brain MRI that unexpectedly identified a large left parietal lobe tumor. Histopathological analysis determined the diagnosis of classic Wilms tumor and choroid-plexus papilloma (CPP), respectively. Both neoplasms showed intense nuclear p53 immunostaining associated with the pathogenic TP53 mutation c.844C > T (p.Arg282Trp). Our patient and her father shared the same heterozygous germline TP53 mutation, confirming the diagnosis of familiar Li-Fraumeni syndrome in the girl. The treatment was tailored to simultaneous tumor presentations. Conclusions LFS has been associated with Choroid plexus carcinoma (CPC), but rarely with CPP as in our patient. That suggests that it may be advisable to consider the possibility of analyzing TP53 mutation, not only in all patients with CPC, but also in some patients with CPP, especially when histological or clinical evidences point out to perform this study. The dissimilar presentation of LFS among our patient’s father, not having so far any neoplasia diagnosed, while her daughter presented precociously with two simultaneous different tumors, could be related to possible effects of modifier genes on the underlying mutant p53 genotype.

Additional file 1.

Central nervous system high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1) is a rare recently described entity. Fourteen CNS HGNET-MN1 patients were identified using genome-wide methylation arrays/RT-PCR across seven institutions. All patients had surgery (gross total resection: 10; subtotal resection: four) as initial management followed by observation alone in three patients, followed by radiotherapy in eight patients (focal: five; craniospinal: two; CyberKnife: one) and systemic chemotherapy in three patients. Seven patients relapsed; five local and two metastatic, despite adjuvant radiotherapy, of which three died. Treatment of CNS HGNET-MN1 remains a major treatment challenge despite aggressive surgical resections and upfront radiotherapy, warranting new approaches to this rare malignancy.

Soft-tissue sarcomas in children comprise a heterogeneous group of entities with variable manifestation depending on the age of the patient and the location of the tumor. MRI is the modality of choice for evaluating musculoskeletal soft-tissue tumors and plays a paramount role in both initial diagnosis and assessment of tumor response during and after treatment. Conventional MRI sequences, such as T1- and T2-weighted imaging, offer morphologic information, which is important for localizing the lesion and describing anatomic relationships but not accurate for determining its malignant or benign nature and may be limited in differentiating tumor response from therapy-related changes. Advanced multiparametric MRI offers further functional information that can help with these tasks by using different imaging sequences and biomarkers. The authors present the role of MRI in rhabdomyosarcoma and other soft-tissue sarcomas in children, emphasizing a multiparametric approach with focus on the utility and potential added value of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI in characterization and staging, determination of pretreatment extent, and evaluation of tumor response and recurrence after treatment. ©RSNA, 2020.

Supplemental material, Table_S1 for Use of patient derived orthotopic xenograft models for real-time therapy guidance in a pediatric sporadic malignant peripheral nerve sheath tumor by Juana Fernández-Rodríguez, Andrés Morales La Madrid, Bernat Gel, Alicia Castañeda Heredia, Héctor Salvador, María Martínez-Iniesta, Catia Moutinho, Jordi Morata, Holger Heyn, Ignacio Blanco, Edgar Creus-Bachiller, Gabriel Capella, Lourdes Farré, August Vidal, Francisco Soldado, Lucas Krauel, Mariona Suñol, Eduard Serra, Alberto Villanueva and Conxi Lázaro in Therapeutic Advances in Medical Oncology

Supplemental material, Supplementary_material_and_methods for Use of patient derived orthotopic xenograft models for real-time therapy guidance in a pediatric sporadic malignant peripheral nerve sheath tumor by Juana Fernández-Rodríguez, Andrés Morales La Madrid, Bernat Gel, Alicia Castañeda Heredia, Héctor Salvador, María Martínez-Iniesta, Catia Moutinho, Jordi Morata, Holger Heyn, Ignacio Blanco, Edgar Creus-Bachiller, Gabriel Capella, Lourdes Farré, August Vidal, Francisco Soldado, Lucas Krauel, Mariona Suñol, Eduard Serra, Alberto Villanueva and Conxi Lázaro in Therapeutic Advances in Medical Oncology

Ewing sarcoma is a bone and soft tissue tumor predominantly affecting adolescents and young adults. To characterize changes in anticancer drug activity and intratumor drug distribution during the evolution of Ewing sarcomas, we used immunodeficient mice to establish pairs of patient-derived xenografts (PDX) at early (initial diagnosis) and late (relapse or refractory progression) stages of the disease from three patients. Analysis of copy number alterations (CNA) in early passage PDX tissues showed that two tumor pairs established from patients which responded initially to therapy and relapsed more than one year later displayed similar CNAs at early and late stages. For these two patients, PDX established from late tumors were more resistant to chemotherapy (irinotecan) than early counterparts. In contrast, the tumor pair established at refractory progression showed highly dissimilar CNA profiles, and the pattern of response to chemotherapy was discordant with those of relapsed cases. In mice receiving irinotecan infusions, the level of SN-38 (active metabolite of irinotecan) in the intracellular tumor compartment was reduced in tumors at later stages compared to earlier tumors for those pairs bearing similar CNAs, suggesting that distribution of anticancer drug shifted toward the extracellular compartment during clonal tumor evolution. Overexpression of the drug transporter P-glycoprotein in late tumor was likely responsible for this shift in drug distribution in one of the cases., The work at Hospital Sant Joan de Deu was supported by associations of parents and families of children with cancer. The work of EdA was supported by the AECC Scientific Foundation (GCB13-1578), ISCIII-FEDER (PI14/01466 and PI17/00464), CIBERONC (CB16/12/00361), Asociación Pablo Ugarte and Fundación María García Estrada. The work of JM was supported by the AECC Scientific Foundation (GCB13-1578) and Asociación Pablo Ugarte. The work of AMC was supported by grants from the AECC Scientific Foundation, MINECO (SAF2011-22660), Fundacion BBVA (152/2011), the European Union Seventh Framework Programme (FP7/2007-2013) under Marie Curie International Reintegration Grant (PIRG-08-GA-2010-276998) and ISCIII-FEDER (CP13/00189 and CPII18/00009).

The failure to develop effective therapies for paediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG) is in part due to their intrinsic heterogeneity. We aimed to quantitatively map assess the extent to which this was present in these tumours through subclonal genomic analyses, and to determine whether distinct tumour subpopulations may interact to promote tumorigenesis by generating novel subclonal patient-derived models in vitro and in vivo. Analysis of 142 sequenced cases revealed multiple tumour subclones, spatially and temporally co-existing in a stable manner as observed by multiple sampling strategies. We isolated genotypically and phenotypically distinct subpopulations which we propose co-operate to enhance tumorigenicity and resistance to therapy. Inactivating mutations in the H4K20 histone methyltransferase KMT5B (SUV420H1), present in

Diffuse intrinsic pontine glioma (DIPG) is an aggressive infiltrative glioma for which no curative therapy is available. Radiation therapy (RT) is the only potentially effective intervention in delaying tumor progression, but only transiently. At progression, re-irradiation is gaining popularity as an effective palliative therapy. However, at second progression, exclusive symptomatic treatment is usually offered. Here we report two patients with DIPG at second progression who were treated with a second re-irradiation course with good response. Importantly, treatment was well tolerated with no irradiation associated acute toxicity identified.

Subcutaneous fat necrosis of the newborn (SCFN) is a rare, self-limited disorder of the panniculus which appears in the first few weeks of life. SCFN generally follows an uncomplicated course. However, there are important complications for which the patient must be regularly monitored, including thrombocytopenia, hypoglycemia, hypertriglyceridemia, and most importantly, hypercalcemia. We report five infants with SCFN. All children were born at term. The onset of lesions was between 1 day and 20 days after birth. The back was the most frequent location. Birth hypoxia was the most frequent risk factor. Complications included hypercalcemia, hypoglycemia, and metastatic calcifications (disseminated subcutaneous calcifications, nephrocalcinosis, and myocardial calcifications). This study provides the first case of SCFN in the context of hypoxic encephalopathy and refractory septic shock that required extracorporeal membrane oxygenation (ECMO).