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An 8-year-old girl presented with precocious puberty and an otherwise normal examination. MRI of the pituitary was normal; however, an incidental oval, non-enhancing T2 hyperintense lesion in the right temporal subcortical white matter was identified ([figure 1][1]). The neuro-radiographic

A 6-year-old boy presented for evaluation after a new onset focal seizure. CT demonstrated a large right hemispheric mass with midline shift ([figure 1A][1]). MRI confirmed a T2 hyperintense tumour with reduced diffusivity, minimal enhancement on postgadolinum sequences, and linear calcifications on

A 16‐year‐old boy with negative past medical history presented to an outside hospital with a first time right‐sided focal seizure. Neurologic examination at presentation was normal. CT performed in the emergency room revealed a large left intra‐axial cerebral mass without haemorrhage ([

A 16-year-old previously healthy boy presented with a 7-year history of ‘black out’ spells. The patient reported that the episodes occurred one to two times in a month associated with dizziness and loss of consciousness without associated urinary or faecal incontinence. At times, he would have

Diffuse midline glioma (DMG) is a leading cause of brain tumor death in children. In addition to hallmark H3.3K27M mutations, significant subsets also harbor alterations of other genes, such asTP53andPDGFRA. Despite the prevalence of H3.3K27M, the results of clinical trials in DMG have been mixed, possibly due to the lack of models recapitulating its genetic heterogeneity. To address this gap, we developed human iPSC-derived tumor models harboring TP53R248Qwith or without heterozygous H3.3K27M and/or PDGFRAD842Voverexpression. The combination of H3.3K27M and PDGFRAD842Vresulted in more proliferative tumors when gene-edited neural progenitor (NP) cells were implanted into mouse brains compared to NP with either mutation alone. Transcriptomic comparison of tumors and their NP cells of origin identified conserved JAK/STAT pathway activation across genotypes as characteristic of malignant transformation. Conversely, integrated genome-wide epigenomic and transcriptomic analyses, as well as rational pharmacologic inhibition, revealed targetable vulnerabilities unique to the TP53R248Q; H3.3K27M; PDGFRAD842Vtumors and related to their aggressive growth phenotype. These includeAREG-mediated cell cycle control, altered metabolism, and vulnerability to combination ONC201/trametinib treatment. Taken together, these data suggest that cooperation between H3.3K27M and PDGFRA influences tumor biology, underscoring the need for better molecular stratification in DMG clinical trials.

PURPOSE Treatment of children with CNS tumors (CNSTs) demands a complex, interdisciplinary approach that is rarely available in low- and middle-income countries. We established the Cross-Border Neuro-Oncology Program (CBNP) between Rady Children’s Hospital, San Diego (RCHSD), and Hospital General, Tijuana (HGT), Mexico, to provide access to neuro-oncology care, including neurosurgic services, for children with CNSTs diagnosed at HGT. Our purpose was to assess the feasibility of the CBNP across the United States-Mexico border and improve survival for children with CNSTs at HGT by implementing the CBNP. PATIENTS AND METHODS We prospectively assessed clinicopathologic profiles, the extent of resection, progression-free survival, and overall survival (OS) in children with CNSTs at HGT from 2010 to 2017. RESULTS Sixty patients with CNSTs participated in the CBNP during the study period. The most common diagnoses were low-grade glioma (24.5%) and medulloblastoma (22.4%). Of patients who were eligible for surgery, 49 underwent resection at RCHSD and returned to HGT for collaborative management. Gross total resection was achieved in 78% of cases at RCHSD compared with 0% at HGT ( P < .001) and was a predictor of 5-year OS (hazard ratio, 0.250; 95% CI, 0.067 to 0.934; P = .024). Five-year OS improved from 0% before 2010 to 52% in 2017. CONCLUSION The CBNP facilitated access to complex neuro-oncology care for underserved children in Mexico through binational exchanges of resources and expertise. Survival for patients in the CBNP dramatically improved. Gross total resection at RCHSD was associated with higher OS, highlighting the critical role of experienced neurosurgeons in the treatment of CNSTs. The CBNP model offers an attractive alternative for children with CNSTs in low- and middle-income countries who require complex neuro-oncology care, particularly those in close proximity to institutions in high-income countries with extensive neuro-oncology expertise.

SUMMARYExtrachromosomal circular DNA (ecDNA) is an important driver of aggressive tumor growth, promoting high oncogene copy number, intratumoral heterogeneity, accelerated evolution of drug resistance, enhancer rewiring, and poor outcome. ecDNA has been reported in medulloblastoma (MB), the most common malignant pediatric brain tumor, but the ecDNA landscape and its association with specific MB subgroups, its impact on enhancer rewiring, and its potential clinical implications, are not known. We assembled a retrospective cohort of 468 MB patient samples with available whole genome sequencing (WGS) data covering the four major MB subgroups WNT, SHH, Group 3 and Group 4. Using computational methods for the detection and reconstruction of ecDNA1, we find ecDNA in 82 patients (18%) and observe that ecDNA+ MB patients are more than twice as likely to relapse and three times as likely to die of disease. In addition, we find that individual medulloblastoma tumors often harbor multiple ecDNAs, each containing different amplified oncogenes along with co-amplified non-coding regulatory enhancers. ecDNA was substantially more prevalent among 31 analyzed patient-derived xenograft (PDX) models and cell lines than in our patient cohort. By mapping the accessible chromatin and 3D conformation landscapes of MB tumors that harbor ecDNA, we observe frequent candidate “enhancer rewiring” events that spatially link oncogenes with co-amplified enhancers. Our study reveals the frequency and diversity of ecDNA in a subset of highly aggressive tumors and suggests enhancer rewiring as a frequent oncogenic mechanism of ecDNAs in MB. Further, these results demonstrate that ecDNA is a frequent and potent driver of poor outcome in MB patients.

BACKGROUND: Understanding viral kinetics of SARS-CoV-2 is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the PCR cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. METHODS: This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children's hospital. RESULTS: We analyzed 728 children who tested positive for SARS-CoV-2 by RT-PCR from a respiratory sample over a 4-month period and for whom data was available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean 19.9, SD 6.3) was significantly lower than asymptomatic patients (Ct mean 23.5, SD 6.5) (P value < 0.001, CI 95th 2.6 - 4.6). The mean PCR Ct value was lowest in children less than 5 years of age. CONCLUSIONS: In this retrospective review of children who tested positive by RT-PCR for SARS CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children under 5 years of age, indicating that symptomatic children and younger children infected with SARS-CoV-2 may have a higher viral load in the nasopharynx compared to asymptomatic children. Further studies are needed to assess the transmission potential from asymptomatic children.

Successful use of immune checkpoint inhibitors in a variety of cancers has generated interest in using this approach in pediatric brain tumors. We performed a retrospective review of 10 consecutive children (6 boys, 4 girls; ages, 2 to 17 y), with recurrent or refractory pediatric brain tumors (5 high-grade glioma, 1 low-grade glioma, pineoblastoma, medulloblastoma, ependymoma, and CNS embryonal tumor, NOS) treated at Rady Children's Hospital San Diego from 2015 to 2017 with the immune checkpoint inhibitor nivolumab (3 mg/kg every 2 wk). Eight of 10 patients received prior chemotherapy and 9 radiation therapy. Nine patients had radiographic disease progression (median, 2.5 doses). Median time to progression was 5.5 weeks (1.6 to 24 wk). Three patients (2 with high-grade glioma, 1 with CNS embryonal tumor NOS) showed a partial response to treatment at the primary tumor site and 2 of 3 had progression of metastatic disease. Grade 2 toxicities were observed without dose limiting side effects. Tumor mutation burden (TMB) was low to intermediate (median, 1.3; range, 0 to 6.3). Median survival for PD-L1 positive patients was 13.7 weeks versus 4.2 weeks for PD-L1 negative patients (ρ=0.08) nivolumab was well tolerated in our series of pediatric recurrent brain tumors with some transient partial responses in patients with positive PD-L1 expression and higher TMB. Our findings suggest that the use of immune checkpoint inhibitors in pediatric brain tumor patients should be limited to those with elevated PD-L1 expression and TMB.

Background Understanding viral kinetics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the polymerase chain reaction (PCR) cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. Methods This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children’s hospital. Results We analyzed 728 children who tested positive for SARS-CoV-2 by reverse-transcription PCR (RT-PCR) from a respiratory sample over a 4-month period and for whom data were available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean, 19.9 [standard deviation, 6.3]) was significantly lower than for asymptomatic patients (Ct mean, 23.5 [standard deviation, 6.9]) (P < .001; 95% confidence interval, 2.6–4.6). The mean PCR Ct value was lowest in children, Of 728 children who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse-transcription polymerase chain reaction, mean cycle threshold (Ct) value was lower in symptomatic children. Children

Background Understanding viral kinetics of SARS-CoV-2 is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. Children have been noted to have less severe illness than adults and may have less transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the PCR cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS CoV-2 infection. Methods This was a retrospective cross-sectional study to compare PCR Ct values of 728 children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period. The study was a single center review of patients who tested positive for SARS-CoV-2 by RT-PCR from a respiratory specimen at a large tertiary care children’s hospital. Inclusion criteria included children 0–18 years of age who tested positive for SARS-CoV-2 by RT-PCR from a respiratory specimen for whom clinical information was available in the electronic medical record. Results We analyzed 728 children who tested positive for SARS-CoV-2 by RT-PCR from a respiratory sample over a 4-month period and for whom data was available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean 19.9, SD 6.3) was significantly lower than asymptomatic patients (Ct mean 23.5, SD 6.5) (P value < 0.001, CI95th 2.6 - 4.6). The mean PCR Ct value was lowest in children less than 5 years of age. Conclusions and Relevance In this retrospective review of children who tested positive by RT-PCR for SARS CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children under 5 years of age.

A delayed hemolytic transfusion reaction (DHTR) is a potential complication for patients with sickle cell disease (SCD) who develop red blood cell (RBC) alloimmunization to foreign antigens from allogeneic transfusions, resulting in life-threatening hemolytic anemia between 24 hours and 28 days after the transfusion. Guidelines have suggested obtaining an extended RBC antigen profile by genotyping in patients with SCD to provide increased accuracy for antigen matching. We present a pediatric patient with SCD and a rare RBC antigen genotype who developed DHTR to describe the significant challenges with antibody identification, the process of obtaining compatible blood, and our medical management.

Diffuse midline glioma is the leading cause of brain tumor death among the pediatric population. Drugs that show notable promise in preclinical models inevitably fail to demonstrate efficacy in clinical trials, likely due to the inadequacy of preclinical models. We have recently proposed glioblastoma models derived from human induced pluripotent stem cells (hiPSCs) genetically engineered with different combinations of glioblastoma-associated genetic alterations as a platform to search for therapeutic targets. These glioblastoma avatars authentically recapitulated the different pathobiology of glioblastoma subtypes, depending on what genetic alterations to be introduced. To investigate the biology and to develop novel therapeutics for diffuse midline glioma with H3K27M mutation, we have established a novel model by introducing H3.3 K27M mutation together with one of the most common concurrent genetic alterations, TP53 R248Q mutation, into hiPSCs through CRISPR/Cas9 genome engineering. Orthotopic engraftment of the neural progenitor cells derived from these edited hiPSCs formed diffusely invasive brainstem tumors with histological features of the diffuse midline glioma. These tumor avatars presented a global reduction in H3K27me3 accompanied by the expression of H3K27M. Transcriptome analyses of these models revealed that these avatars with H3K27M cluster apart from the pediatric glioma samples without this particular mutation, and that they present signatures of oligodendroglial progenitor differentiation as discovered in patient samples with this mutation. Using these models faithfully recapitulating histology and pathobiology of the patient tumors, we have performed drug screening and confirmed that their sensitivity to known drugs, including an EZH2 inhibitor and histone deacetylase inhibitors. On these faithful human avatars of diffuse midline glioma with H3K27M, we have applied bioinformatics algorithms of drug sensitivity prediction aiming at developing novel therapeutics for this devastating pediatric glioma.

Ependymoma is a tumor of the brain or spinal cord. The two most common and aggressive molecular groups of ependymoma are the supratentorial RELA-fusion associated group and the posterior fossa ependymoma group A. In both groups, tumors occur mainly in young children and frequently recur after treatment1. Although the molecular mechanisms underlying these diseases have recently been uncovered, they remain difficult to target and innovative therapeutic approaches are urgently needed. Here, we use genome-wide chromosome conformation capture (Hi-C), complemented with CTCF (insulators) and H3K27ac (active enhancers) ChIP-seq as well as gene expression and whole-genome DNA methylation profiling in primary and relapsed ependymoma tumors and cell lines to identify chromosomal rearrangements and regulatory mechanisms underlying aberrant expression of genes that are essential for ependymoma tumorigenesis. In particular, we observe the formation of new topologically associating domains (‘neo-TADs’) by intra- and inter-chromosomal structural variants, tumor-specific 3D chromatin complexes of regulatory elements, and the replacement of CTCF insulators by DNA hyper-methylation as novel oncogenic mechanisms in ependymoma. Through inhibition experiments we validated that the newly identified genes, including RCOR2, ITGA6, LAMC1, and ARL4C, are highly essential for the survival of patient-derived ependymoma models in a disease subtype-specific manner. Thus, this study identifies potential novel therapeutic vulnerabilities in ependymoma and extends our ability to reveal tumor-dependency genes and pathways by oncogenic 3D genome conformations even in tumors that lack known genetic alterations.

Medulloblastoma is among the most common malignant brain tumors in children. Recent studies have identified at least four subgroups of the disease that differ in terms of molecular characteristics and patient outcomes. Despite this heterogeneity, most patients with medulloblastoma receive similar therapies, including surgery, radiation, and intensive chemotherapy. Although these treatments prolong survival, many patients still die from the disease and survivors suffer severe long-term side effects from therapy. We hypothesize that each patient with medulloblastoma is sensitive to different therapies and that tailoring therapy based on the molecular and cellular characteristics of patients' tumors will improve outcomes. To test this, we assembled a panel of orthotopic patient-derived xenografts (PDX) and subjected them to DNA sequencing, gene expression profiling, and high-throughput drug screening. Analysis of DNA sequencing revealed that most medulloblastomas do not have actionable mutations that point to effective therapies. In contrast, gene expression and drug response data provided valuable information about potential therapies for every tumor. For example, drug screening demonstrated that actinomycin D, which is used for treatment of sarcoma but rarely for medulloblastoma, was active against PDXs representing Group 3 medulloblastoma, the most aggressive form of the disease. Functional analysis of tumor cells was successfully used in a clinical setting to identify more treatment options than sequencing alone. These studies suggest that it should be possible to move away from a one-size-fits-all approach and begin to treat each patient with therapies that are effective against their specific tumor. Significance: These findings show that high-throughput drug screening identifies therapies for medulloblastoma that cannot be predicted by genomic or transcriptomic analysis.

A previously healthy 6-year-old boy presented with acute onset of headache, vomiting and right sided weakness. CT imaging was performed which revealed an intracerebral left-sided 7 cm haemorrhagic mass associated with midline shift ([figure 1][1]). The patient subsequently developed signs of

We present eight families with arthrogryposis multiplex congenita and myopathy bearing a TTN intron 213 extended splice-site variant (NM_001267550.1:c.39974-11T>G), inherited in trans with a second pathogenic TTN variant. Muscle-derived RNA studies of three individuals confirmed mis-splicing induced by the c.39974-11T>G variant; in-frame exon 214 skipping or use of a cryptic 3' splice-site effecting a frameshift. Confounding interpretation of pathogenicity is the absence of exons 213-217 within the described skeletal muscle TTN N2A isoform. However, RNA-sequencing from 365 adult human gastrocnemius samples revealed that 56% specimens predominantly include exons 213-217 in TTN transcripts (inclusion rate ≥66%). Further, RNA-sequencing of five fetal muscle samples confirmed that 4/5 specimens predominantly include exons 213-217 (fifth sample inclusion rate 57%). Contractures improved significantly with age for four individuals, which may be linked to decreased expression of pathogenic fetal transcripts. Our study extends emerging evidence supporting a vital developmental role for TTN isoforms containing metatranscript-only exons. ispartof: Human Mutation vol:41 issue:2 pages:403-411 ispartof: location:United States status: Published online

The implementation of next-generation sequencing (NGS) in pediatric neuro-oncology may impact diagnosis, prognosis, therapeutic strategies, clinical trial enrollment, and germline risk. We retrospectively analyzed 58 neuro-oncology patients (31 boys, 27 girls, average age 7.4 years) who underwent NGS tumor profiling using a single commercially available platform on paraffin-embedded tissue obtained at diagnosis (20 low-grade gliomas, 12 high-grade gliomas, 11 embryonal tumors, four ependymal tumors, three meningeal tumors, and eight other CNS tumors) from May 2014 to December 2016. NGS results were analyzed for actionable mutations, variants of unknown significance and clinical impact. Seventy-four percent of patients (43 of 57) had actionable mutations; 26% had only variants of uncertain significance (VUS). NGS findings impacted treatment decisions in 55% of patients; 24% were given a targeted treatment based on NGS findings. Seven of eight patients with low-grade tumors treated with targeted therapy (everolimus, trametinib, or vemurafenib) experienced partial response or stable disease. All high-grade tumors had progressive disease on targeted therapy. Forty percentof patients had a revision or refinement of their diagnosis, and nine percent of patients were diagnosed with a previously unconfirmed cancer predisposition syndrome. Turnaround time between sample shipment and report generation averaged 13.4 ± 6.4 days. One sample failed due to insufficient DNA quantity. Our experience highlights the feasibility and clinical utility of NGS in the management of pediatric neuro-oncology patients. Future prospective clinical trials using NGS are needed to establish efficacy.

A 16-year-old female adolescent with a history of high-risk pre-B acute lymphoblastic leukaemia in remission after 2 years following chemotherapy and whole brain irradiation was seen for a follow-up oncological visit, where she was found to have suicidal indications. The patient’s mother had died

The spontaneous involution and rapid recurrence of a Rathke’s cleft cyst (RCC) is not well described. A 16-year-old female with a putatively incidental nearly 2 cm suprasellar lesion arising from the posterior aspect of the infundibulum found on a brain MRI during workup for aseptic meningitis demonstrated a spontaneous and near-complete involution of this lesion on close follow up (leaving only a thickened infundibulum measuring up to 3.6 mm). After a period of cyclic headaches coinciding with subtle changes in pituitary stalk thickness, she developed progressive fatigue, severe headaches, and bitemporal blurry vision, with rapid re-growth of the suprasellar lesion to near its original size seen on repeat MRI. Due to its purely suprasellar and retro-infundibular location an anterolateral rather than an anterior transnasal approach was recommended. She underwent a successful orbitofrontal craniotomy and cyst fenestration/partial resection, with pathologic analysis confirming an RCC. Post-operatively, she had normal vision and no diabetes insipidus or other hormonal disturbances, and improvement of her headaches on ten-month follow up. Awareness of the potentially dynamic nature of RCCs is important for their timely diagnosis. Purely suprasellar RCCs can require an anterolateral surgical approach, especially when located posterior to the infundibulum.

A 12-year-old boy with Down syndrome (DS), myeloproliferative disorder and autism spectrum disorder presented for new-onset seizures. The patient did not report any headaches, weakness, nausea or vomiting, and neurological examination was non-focal. MRI revealed a mixed solid and cystic 13 mm mass

A 13-year-old boy with no significant medical history presented with 6 months of progressive visual loss in the right eye. Ophthalmological examination demonstrated a right-sided afferent pupillary defect, absent vision and a pale optic nerve. CT revealed a lytic lesion involving the right orbital

A 14-year-old girl presented with 10 months of worsening headaches with associated nausea and 1 month of visual impairment, including blurry and double vision. Her headaches initially occurred monthly but increased in frequency and became intractable to medical management. Physical examination was

A 16-year-old girl with a prior history of a dysembryoplastic neuroepithelial tumour (DNET) diagnosed at the age of 6 years, treated with a gross total resection and followed by serial imaging, who had been seizure-free, presented with a focal seizure. MRI revealed recurrence of a peripherally

Many mouse and human glioma models have been utilized to study the genetic alterations involved in the genesis of these tumors, but they have not been fully evaluated for how closely they recapitulate pathobiology, including tumor heterogeneity, which is an inherent feature making patient treatment difficult. Here we present new glioma models using genetically engineered human pluripotent stem cells, in which authentic pathobiology is recapitulated through precision gene editing. Specifically, we show that neural progenitor cells (NPCs) derived from human induced pluripotent stem cells (iPSCs), with different combinations of genetic drivers introduced by CRISPR/Cas9-mediated editing give rise to distinct intracranial tumors recapitulating authentic pathobiology of the disease when engrafted in immunocompromised mice. NPCs deficient in PTEN and NF1, a genotype associated with the mesenchymal molecular subtype, and NPCs deficient in TP53 and expressing a PDGFRA activating mutation (PDGFRAΔ8–9), a genotype associated with the proneural glioblastoma molecular subtype, give rise to distinct tumors resembling glioblastoma. Both models presented inter and intra-tumor heterogeneity based on single-cell RNA sequencing, with the former model showing proneural signature and the latter a mesenchymal signature, and both having different degrees of cycling, and stem cell-enriched populations. The TP53/PDGFRA model had more clonal variability related with striking karyotype abnormalities including extrachromosomal DNA. Additionally, we expanded this approach to pediatric gliomas. Brainstem tumors derived from NPCs introduced with TP53 R248Q and H3F3A K27M mutations presented features of glial tumors with global expression of histone H3 K27M accompanied by suppression of histone H3K27 trimethylation, compatible with H3 K27M-mutant pediatric diffuse midline glioma. Using these isogenic human brain tumor models, we aim to advance our understanding of the pathobiology associated with different driver mutations and further, to provide a platform for development of targeted therapy.

A previously healthy 3-month-old former 30-week premature girl presented with sudden onset altered mental status and cardiopulmonary arrest.[1][1] CT scan showed a 10.2 cm hyperdense lesion in the right hemisphere with areas of acute haemorrhage causing subfalcine, uncal and inferior cerebellar

A previously healthy 9-year-old girl presented to otolaryngology clinic due to new onset bilateral sensorineural hearing loss. An MRI brain was ordered as part of her routine workup, and she was found to have an incidental 1.3 cm non-enhancing T1 hypointense, T2 hyperintense mass in the right

A 10-year previously healthy boy presented with unusual episodes of recurrent frontal headaches lasting 30 s associated with the abnormal smell that would occur several times per week. He had no focal weakness, sensory changes or loss of consciousness during the episodes and had a non-focal

A 17-year-old man with a several week-long history of lower left leg pain presented with lower left leg paresthesia and weakness. MRI of the spine revealed a non-enhancing extradural mass at L4 with compression of the cauda equina ([figure 1][1]). The patient underwent L4–L5 laminectomy, followed

A previously healthy 11-year-old boy presented with self-limited recurrent episodes of dizziness, disorientation and visual changes with a normal neurological examination. MRI revealed a well-circumscribed mixed solid/cystic left parieto-occipital mass ([figure 1][1]). He underwent a gross total

Objective To characterize the clinical phenotype, genetic origin, and muscle pathology of patients with the FKRP c.1387A>G mutation. Methods Standardized clinical data were collected for all patients known to the authors with c.1387A>G mutations in FKRP. Muscle biopsies were reviewed and used for histopathology, immunostaining, Western blotting, and DNA extraction. Genetic analysis was performed on extracted DNA. Results We report the clinical phenotypes of 6 patients homozygous for the c.1387A>G mutation in FKRP. Onset of symptoms was G patients revealed a 500-kb region of shared homozygosity at 19q13.32, including FKRP. All 4 muscle biopsies available for review showed end-stage dystrophic pathology, near absence of glycosylated α-dystroglycan (α-DG) by immunofluorescence, and reduced molecular weight of α-DG compared with controls and patients with homozygous FKRP c.826C>A limb-girdle muscular dystrophy. Conclusions The clinical features and muscle pathology in these newly reported patients homozygous for FKRP c.1387A>G confirm that this mutation causes congenital muscular dystrophy. The clinical severity might be explained by the greater reduction in α-DG glycosylation compared with that seen with the c.826C>A mutation. The shared region of homozygosity at 19q13.32 indicates that FKRP c.1387A>G is a founder mutation with an estimated age of 60 generations (∼1,200–1,500 years).

An 11-year-old girl presented with global developmental delay. As part of her routine work-up for her developmental disability, MRI of the brain was performed and demonstrated a contrast-enhancing lesion with reduced diffusivity in the right parietal lobe (figure 1). A stereotactic robotic-assisted needle biopsy revealed microglial proliferation and lymphocytic inflammation, indicating potential microglioma or gliofibroma; however, a more definitive diagnosis was not established given the limited tissue. Early repeat MRI showed areas of progression, and gross total resection was performed. The pathology demonstrated a moderately cellular proliferation of spindle cells with scattered mitotic figures, and a mixed inflammatory infiltrate of scattered lymphocytes, plasma cells and eosinophils (figure 2A). The areas of nodular spindle cell proliferation were diffusely immunopositive for CD68 and negative for CD30, …

Tumor cells evade immune-mediated destruction through activation of checkpoints. Successful use of the immune checkpoint inhibitors in certain cancer types has generated interest in using this approach in pediatric brain tumors. Ten consecutive children (6 boys, 4 girls, mean age 11 years, range 2-17 years) with pediatric recurrent or refractory pediatric brain tumors (4 high grade glioma, 2 pineoblastoma, 1 disseminated low grade glioma, 1 medulloblastoma, 1 ependymoma, 1 primitive neuro-ectodermal tumor) were treated at Rady Children’s Hospital San Diego from 2015-2017 with the immune checkpoint inhibitor nivolumab (3 mg/kg every 2 weeks). Eight had received prior chemotherapy and 9 received prior radiation therapy. Seven had radiographic progression of disease (total 36 doses, mean 3.6 doses) with mean time to progression of 5.4 weeks (range 1.6-13.7 weeks). One patient voluntarily discontinued treatment after stable disease at 24 weeks and 2 patients showed either transient stability or partial response of brain disease but worsening of metastatic disease. There were no dose limiting side effect observed, however there was a 10 % incidence of elevated ALT, hyperglycemia, pancreatitis and hypo-albuminemia. Although the tumor mutation burden (TMB) was low (mean 2, range 0-6.3), there was a trend between TMB and time to progression. PDL-1 immuno-histochemical analysis and next generation sequencing data on each tumor will be presented. Our findings suggest nivolumab is well tolerated in pediatric patients with recurrent brain tumors. Future randomized controlled studies stratifying for TMB may be necessary to demonstrate the efficacy of PD-L1 inhibitors in recurrent pediatric brain tumors.

Lymphangioma of the urogenital system is extremely rare and we present two cases treated at our institution over a one year period. The first case is a 3 year-old boy who presented with scrotal swelling and was initially thought to have a complex hydrocele. On surgical exploration, an extratesticular multiloculated cystic mass was discovered and testis-sparing excision of the mass was performed. Pathology revealed lymphangioma. The second case is a 5 year-old male who initially presented with gross hematuria. Ultrasound was unremarkable but cystoscopy revealed varicosities extending from the bladder wall. On transurethral resection, histology showed non-specific benign vascular malformation. Magnetic resonance imaging (MRI) was obtained because of persistent hematuria and showed multiple bladder lesions suggestive of lymphatic malformation. Partial cystectomy was ultimately performed and histology confirmed lymphangioma. To the author's knowledge, this represents the fifth reported case of lymphangioma of bladder.

The management of airway obstruction in children is often challenging with acute presentation and uncertainty in the diagnosis. We report a case of a young child with acute onset biphasic stridor who was found to have a large subglottic lesion causing significant airway obstruction. We were able to successfully resect it to achieve a pathologic diagnosis and address the subglottic stenosis with an anterior laryngofissure followed by laryngotracheal reconstruction (LTR) using a rib graft. The final pathology was diffuse large B-cell lymphoma, anaplastic variant, and patient had complete response to chemotherapy and is currently free of disease.

OBJECTIVE:The performance of automated flow cytometric urinalysis is not well described in pediatric urinary tract infection. We sought to determine the diagnostic performance of automated cell counts and emergency department point-of-care (POC) dipstick urinalyses in the evaluation of young febrile children.METHODS:We prospectively identified a convenience sample of febrile pediatric emergency department patients RESULTS:Of 342 eligible children, 42 (12%) had urinary bacterial growth ≥50 000/mL. The areas under the receiver operating characteristic curves were: automated white blood cell count, 0.97; automated bacterial count, 0.998; POC leukocyte esterase, 0.94; and POC nitrite, 0.76. Sensitivities and specificities were 86% and 98% for automated leukocyte counts ≥100/μL and 98% and 98% for bacterial counts ≥250/μL. POC urine dipstick with ≥1+ leukocyte esterase or positive nitrite had a sensitivity of 95% and a specificity of 98%. Combinations of white blood cell and bacterial counts did not outperform bacterial counts alone.CONCLUSIONS:Automated leukocyte and bacterial counts performed well in the diagnosis of urinary tract infection in these febrile pediatric patients, but POC dipstick may be an acceptable alternative in clinical settings that require rapid decision-making.

ObjectiveTo characterize the clinical phenotype, genetic origin, and muscle pathology of patients with the FKRP c.1387A>G mutation.MethodsStandardized clinical data were collected for all patients known to the authors with c.1387A>G mutations in FKRP. Muscle biopsies were reviewed and used for histopathology, immunostaining, Western blotting, and DNA extraction. Genetic analysis was performed on extracted DNA.ResultsWe report the clinical phenotypes of 6 patients homozygous for the c.1387A>G mutation in FKRP. Onset of symptoms was FKRP c.1387A>G patients revealed a 500-kb region of shared homozygosity at 19q13.32, including FKRP. All 4 muscle biopsies available for review showed end-stage dystrophic pathology, near absence of glycosylated α-dystroglycan (α-DG) by immunofluorescence, and reduced molecular weight of α-DG compared with controls and patients with homozygous FKRP c.826C>A limb-girdle muscular dystrophy.ConclusionsThe clinical features and muscle pathology in these newly reported patients homozygous for FKRP c.1387A>G confirm that this mutation causes congenital muscular dystrophy. The clinical severity might be explained by the greater reduction in α-DG glycosylation compared with that seen with the c.826C>A mutation. The shared region of homozygosity at 19q13.32 indicates that FKRP c.1387A>G is a founder mutation with an estimated age of 60 generations (∼1,200–1,500 years).

Paediatric high-grade gliomas, including glioblastoma and anaplastic astrocytoma, make up 8%–12% of paediatric central nervous system tumours 1 and have poor prognosis, with 2-year survival less than 30% 2 and overall survival less than 10%. The only known prognostic factors in this population include extent of resection and tumour histological grade. We present the case of a 9-year-old boy with disseminated anaplastic astrocytoma treated with subtotal resection, craniospinal radiation and temozolomide, with 8-year survival despite metastatic disease at presentation and subtotal resection. Next generation cancer gene panel sequencing revealed an usual pattern of 12 amplifications and four mutations not previously described.

We present the case of a 13-year-old boy with a very unusual periventricular atypical central neurocytoma with unique molecular features treated with subtotal surgical resection and photon intensity-modulated radiotherapy. Histological features were most consistent with atypical central neurocytoma. However, next-generation sequencing analysis revealed a novel EWSR1-ATF1 gene fusion (EWSR1-ATF1) as well as a MUTYH mutation. The EWSR1-ATF1 raised the possibility of Ewing sarcoma or angiomatoid fibrous histiocytoma, however, FLI-1 immunohistochemistry was negative. MUTYH mutations have been reported in diffuse midline paediatric glioma. The role of EWSR1-ATF1 and MUTYH mutations in central nervous system tumours is not well established. We present the first case of EWSR1-ATF1 and MUTYH mutation in a rare paediatric atypical central neurocytoma. Further studies are indicated to elucidate the consequences of these gene alterations in the context of paediatric central nervous system tumours as well as to investigate the potential role for targeted therapies.

Sonic hedgehog (SHH) medulloblastoma (MB) subtype is driven by a proliferative CD15+ tumor propagating cell (TPC), also considered in the literature as a putative cancer stem cell (CSC). Despite considerable research, much of the biology of this TPC remains unknown. We report evidence that phosphatase and tensin homolog (PTEN) and phosphoinositide 3-kinase (PI-3K) play a crucial role in the propagation, survival and potential response to therapy in this CD15+ CSC/TPC-driven malignant disease. Using the ND2-SmoA1 transgenic mouse model for MB, mouse genetics and patient-derived xenografts (PDXs), we demonstrate that the CD15+TPCs are 1) obligately required for SmoA1Tg-driven tumorigenicity 2) regulated by PTEN and PI-3K signaling 3) selectively sensitive to the cytotoxic effects of pan PI-3K inhibitors in vitro and in vivo but resistant to chemotherapy 4) in the SmoA1Tg mouse model are genomically similar to the SHH human MB subgroup. The results provide the first evidence that PTEN plays a role in MB TPC signaling and biology and that PI-3K inhibitors target and suppress the survival and proliferation of cells within the mouse and human CD15+ cancer stem cell compartment. In contrast, CD15+ TPCs are resistant to cisplatinum, temozolomide and the SHH inhibitor, NVP-LDE-225, agents currently used in treatment of medulloblastoma. These studies validate the therapeutic efficacy of pan PI-3K inhibitors in the treatment of CD15+ TPC dependent medulloblastoma and suggest a sequential combination of PI-3K inhibitors and chemotherapy will have augmented efficacy in the treatment of this disease.

This chapter reviews the most common causes of renal masses, both benign and malignant, in the pediatric population. Renal masses are usually incidental and may be found during routine physical examination. Pediatric renal neoplasms are rare, lack specific symptomatology, and may confer challenges during clinical and histopathological diagnosis. The management of renal masses relies on the final pathologic diagnosis, which can lead to different courses of treatment. Radiology and clinical history guide the diagnosis, determine correct preoperative approach, and can help exclude nonneoplastic pseudotumor-like masses. The distinction between nonneoplastic lesions and benign or malignant neoplasia is crucial for correct approach and patient care. Wilms tumor is the most common malignant renal neoplasm of the pediatric kidney, accounting for 92 % of kidney tumors diagnosed in children under 5 years of age. Numerous benign and malignant neoplasms can mimic this tumor and affect the course of treatment. This chapter provides a multidisciplinary compendium for clinicians and pathologists to confidentially evaluate, diagnose, and treat the vast spectrum of pediatric renal masses.

Background Atypical teratoid rhabdoid tumor is a rare malignant neoplasm that represents 1%–2% of all pediatric central nervous system tumors. Immunohistochemistry plays an important role in establishing the diagnosis with a loss of INI-1 staining in tumor cells. In this case report, we describe a teenager with an unusual presentation and pattern of infiltration of the tumor. Case Description A 13-year-old boy presented with a history over several months of progressive nausea, weight loss, and hoarseness of voice associated with multiple lower cranial nerve palsies on neurologic examination. Magnetic resonance imaging revealed a large heterogeneously enhancing extra-axial neoplasm with extension and bony expansion of the jugular foramen. After near total resection, neuropathology demonstrated the absence of INI-1 expression consistent with a diagnosis of atypical teratoid rhabdoid tumor. Conclusions This case highlights the diverse clinical presentation and infiltrative potential of atypical teratoid rhabdoid tumors, thus expanding the differential diagnosis of extra-axial tumors invading the jugular foramen.

Primary angiitis of the central nervous system is a rare idiopathic vasculitis predominantly affecting the central nervous system. The literature includes 10 histologically confirmed cases in childhood. We identify two additional cases, one presenting with both uveitis and cerebrospinal fluid neutrophilic pleocytosis, which has not been reported previously, and demonstrate the importance of biopsy in suspected cases.