Pediatric spinal ependymoma with chromothripsis of chromosome 6: a case report and review of the literature.

BACKGROUND: Ependymomas are the third most common central nervous system tumor in the pediatric population; however, spinal ependymomas in children are rare. Ependymomas affecting the spinal cord most frequently occur in adults of 20-40 years of age. The current World Health Organization classification system for ependymomas is now composed of ten different entities based on histopathology, location, and molecular studies, with evidence that the new classification system more accurately predicts clinical outcomes. CASE PRESENTATION: We present the case of a 16-year-old Caucasian female patient with a history of type 2 neurofibromatosis with multiple schwannomas, meningioma, and spinal ependymoma. Chromosome analysis of the harvested spinal ependymoma tumor sample revealed a 46,XX,-6,+7,-22,+mar[16]/46,XX[4] karyotype. Subsequent OncoScan microarray analysis of the formalin-fixed paraffin-embedded tumor sample confirmed + 7, -22 and clarified that the marker chromosome represents chromothripsis of the entire chromosome 6 with more than 100 breakpoints. Fluorescent in situ hybridization and microarray analysis showed no evidence of MYCN amplification. The final integrated pathology diagnosis was spinal ependymoma (central nervous system World Health Organization grade 2 with no MYCN amplification. CONCLUSION: This case adds to the existing literature of pediatric patients with spinal ependymomas and expands the cytogenetic findings that may be seen in patients with this tumor type. This case also highlights the value of cytogenetics and microarray analysis in solid tumors to provide a more accurate molecular diagnosis.

ROS1 Alterations as a Potential Driver of Gliomas in Infant, Pediatric, and Adult Patients.

Gliomas harboring oncogenic ROS1 alterations are uncommon and primarily described in infants. Our goal was to characterize the clinicopathological features and molecular signatures of the full spectrum of ROS1 fusion-positive gliomas across all age groups. Through a retrospective multi-institutional collaboration, we report a collection of unpublished ROS1 fusion gliomas along with the characterization and meta-analysis of new and published cases. A cohort of 32 new and 58 published cases was divided into the following 3 age groups: 19 infants, 40 pediatric patients, and 31 adults with gliomas. Tumors in infants and adults showed uniformly high-grade morphology; however, tumors in pediatric patients exhibited diverse histologic features. The GOPC::ROS1 fusion was prevalent (61/79, 77%) across all age groups, and 10 other partner genes were identified. Adult tumors showed recurrent genomic alterations characteristic of IDH wild-type glioblastoma, including the +7/-10/CDKN2A deletion; amplification of CDK4, MDM2, and PDGFRA genes; and mutations involving TERTp, TP53, PIK3R1, PIK3CA, PTEN, and NF1 genes. Infant tumors showed few genomic alterations, whereas pediatric tumors showed moderate genomic complexity. The outcomes were significantly poorer in adult patients. Although not statistically significant, tumors in infant and pediatric patients with high-grade histology and in hemispheric locations appeared more aggressive than tumors with lower grade histology or those in nonhemispheric locations. In conclusion, this study is the largest to date to characterize the clinicopathological and molecular signatures of ROS1 fusion-positive gliomas from infant, pediatric, and adult patients. We conclude that ROS1 likely acts as a driver in infant and pediatric gliomas and as a driver or codriver in adult gliomas. Integrated comprehensive clinical testing might be helpful in identifying such patients for possible targeted therapy.

Oropharyngeal Teratoma: Five-Month-Old Presenting With Failure to Thrive and Severe Obstructive Sleep Apnea.

Oropharyngeal teratomas are an extremely rare congenital tumor. They are often diagnosed prenatally and can cause significant airway obstruction and feeding difficulties at birth. We present a five-month-old female that was diagnosed with a palatal teratoma that presented with failure to thrive, difficulty feeding, and eventually with severe obstructive sleep apnea. We present a five-month-old term, otherwise healthy female who became stridulous after an episode of the respiratory syncytial virus at one month old. At three months old, an otolaryngologist diagnosed mild laryngomalacia with no mass identified, and no surgical intervention was recommended. Due to continued poor weight gain, at four months old, a nasogastric tube was placed. She was subsequently admitted for further workup. She had severe stridor, a failure to thrive, and was in the 0.07th percentile for weight. Workup revealed severe obstructive sleep apnea and a palatal mass obstructing her left oropharynx. A biopsy and debulking of the mass was performed in the operating room. Pathology resulted as a mature teratoma with evidence of glial and intestinal tissue. There are no pathognomonic characteristics found on imaging to diagnose teratomas, and diagnosis is made with pathologic identification of two of the three germ cell layers. Although most teratomas are benign, there is potential for malignant transformation involving any of the represented germ cell layers. Many teratomas are diagnosed prenatally and can be quite large, often requiring Ex Utero Intrapartum Treatment (EXIT) procedure at birth to establish a safe airway. Overall, this case highlights the importance of a thorough head and neck exam, including a bilateral flexible laryngoscopy, when evaluating an infant with airway obstruction. Providers evaluating these patients should consider oropharyngeal masses, such as teratoma, as part of the differential to ensure accurate and timely diagnosis.

Integrated genetic profiling of archival pediatric high-grade glial tumors and reassessment with 2021 WHO classification of paediatric CNS tumours.

Though rare, pediatric high-grade gliomas (pHGG) are a leading cause of cancer-related mortality in children. We wanted to determine whether our currently available clinical laboratory methods could better define diagnosis for pHGG that had been archived at our institution for the past 20 years (1998 to 2017). We investigated 33 formalin-fixed paraffin-embedded pHGG using ThermoFisher Oncoscan SNP microarray with somatic mutation analysis, Sanger sequencing, and whole genome sequencing. These data were correlated with historical histopathological, chromosomal, clinical, and radiological data. Tumors were subsequently classified according to the 2021 WHO Classification of Paediatric CNS Tumours. All 33 tumors were found to have genetic aberrations that placed them within a 2021 WHO subtype and/or provided prognostic information; 6 tumors were upgraded from WHO CNS grade 3 to grade 4. New pHGG genetic features were found including two small cell glioblastomas with H3 G34 mutations not previously described; one tumor with STRN-NTRK2 fusion; and a congenital diffuse leptomeningeal glioneuronal tumor without a chromosomal 1p deletion but with KIAA1549-BRAF fusion. Overall, the combination of laboratory methods yielded key information for tumor classification. Thus, even small studies of these uncommon tumor types may yield new genetic features and possible new subtypes that warrant future investigations.

Therapeutic targeting of prenatal pontine ID1 signaling in diffuse midline glioma.

BACKGROUND: Diffuse midline gliomas (DMG) are highly invasive brain tumors with rare survival beyond two years past diagnosis and limited understanding of the mechanism behind tumor invasion. Previous reports demonstrate upregulation of the protein ID1 with H3K27M and ACVR1 mutations in DMG, but this has not been confirmed in human tumors or therapeutically targeted. METHODS: Whole exome, RNA, and ChIP-sequencing was performed on the ID1 locus in DMG tissue. Scratch-assay migration and transwell invasion assays of cultured cells were performed following shRNA-mediated ID1-knockdown. In vitro and in vivo genetic and pharmacologic [cannabidiol (CBD)] inhibition of ID1 on DMG tumor growth was assessed. Patient-reported CBD dosing information was collected. RESULTS: Increased ID1 expression in human DMG and in utero electroporation (IUE) murine tumors is associated with H3K27M mutation and brainstem location. ChIP-sequencing indicates ID1 regulatory regions are epigenetically active in human H3K27M-DMG tumors and prenatal pontine cells. Higher ID1-expressing astrocyte-like DMG cells share a transcriptional program with oligo/astrocyte-precursor cells (OAPCs) from the developing human brain and demonstrate upregulation of the migration regulatory protein SPARCL1. Genetic and pharmacologic (CBD) suppression of ID1 decreases tumor cell invasion/migration and tumor growth in H3.3/H3.1K27M PPK-IUE and human DIPGXIIIP* in vivo models of pHGG. The effect of CBD on cell proliferation appears to be non-ID1 mediated. Finally, we collected patient-reported CBD treatment data, finding that a clinical trial to standardize dosing may be beneficial. CONCLUSIONS: H3K27M-mediated re-activation of ID1 in DMG results in a SPARCL1+ migratory transcriptional program that is therapeutically targetable with CBD.

Anaplastic Lymphoma Kinase Inhibitor in Treatment of Inflammatory Myofibroblastic Tumor of the Tongue in Infancy.

Inflammatory myofibroblastic tumors (IMTs) are rare in neonates. IMTs of the tongue are also very rare in infancy, with only 1 case reported in this age group. The mainstay of therapy has traditionally been surgery, which can be devastating to surrounding structures and negatively impact prognosis. Approximately 50% of IMTs harbor a translocation involving the anaplastic lymphoma kinase gene. We describe a case of IMT of the tongue in a neonate treated with debulking and an anaplastic lymphoma kinase inhibitor. The patient achieved complete response and remains disease-free 1.5 year following completion of therapy.

Clinical Validation of Somatic Mutation Detection by the OncoScan CNV Plus Assay.

The OncoScan CNV Plus Assay (OS+) is a single-nucleotide polymorphism microarray platform that can detect 74 hotspot somatic mutations (SMs) in nine genes via molecular inversion probes. We report validation of the SM component of OS+ using a cohort of pediatric high-grade brain tumor specimens. SM calls were generated from 46 brain tumor cases, most tested orthogonally via bidirectional Sanger sequencing. The initial calling algorithm result showed that 31 tumors were positive and 15 were negative for SM, with a total of 71 OS+ SM calls [28 high-confidence (HC) and 43 low-confidence (LC)]. Sanger sequencing was performed for 54 of the 71 calls (27 HC and 27 LC), as well as for 21 randomly selected hotspots across the 15 OS+ negative cases. HC calls (except EGFR) Sanger sequencing confirmed positive, negative calls confirmed negative, but none of the LC calls were Sanger-confirmed positive. An update of the OS+ algorithm resolved the LC calls, but of the 11 HC SM EGFR calls, Sanger sequencing confirmed only one. Two PTEN SM calls by OS+ in two separate cases were also negative per Sanger sequencing. We conclude that a majority of HC OS+ SM calls were accurate, except calls identified in EGFR and PTEN. Clinically, we report SMs identified by OS+ only after Sanger sequencing verification.

Application of 2016 WHO classification in the diagnosis of paediatric high-grade MYC-negative mature B-cell lymphoma with Burkitt-like morphological features.

AIMS: Historically, there has been no consensus on the diagnostic classification of high-grade B-cell lymphoma (HGBCL) with morphological features of Burkitt lymphoma (BL) but no MYC gene rearrangement (MYC-negative). The 2016 WHO classification of tumours of haematopoietic and lymphoid tissues has shed some light on this field with the modification of the grey-zone lymphoma with features intermediate between BL and diffuse large B-cell lymphoma, and the creation of several new entities. The aim of this study was to investigate how the revised WHO classification affects our practice in diagnosing these lymphomas in children. METHODS: We retrospectively reviewed cases of mature HGBCL diagnosed at our hospital between 2015 and 2018. RESULTS: Among 14 mature HGBCL cases with BL morphological features, 11 showed MYC rearrangement consistent with BL and 3 were MYC-negative. Two MYC-negative cases showed regions of 11q gain and loss by microarray consistent with Burkitt-like lymphoma with 11q aberration (BLL-11q). The third MYC-negative case showed diffuse and strong MUM1 expression, translocation involving 6p25 by chromosome analysis and IRF4 rearrangement by fluorescence in situ hybridisation analysis consistent with large B-cell lymphoma with IRF4 rearrangement (LBL-IRF4). All patients were treated according to applicable chemotherapeutic protocols and achieved remission. CONCLUSIONS: BLL-11q and LBL-IRF4, two newly defined entities, should be considered in paediatric MYC-negative mature HGBCL cases. Accurate diagnosis needs careful histopathological examination and proper cytogenetic testing. Since they have unique cytogenetic features, specific treatments for them may emerge in the future. Therefore, accurate diagnosis based on the 2016 WHO classification is clinically significant.

Near haploidization is a genomic hallmark which defines a molecular subgroup of giant cell glioblastoma.

BACKGROUND: Giant cell glioblastoma (gcGBM) is a rare histologic subtype of glioblastoma characterized by numerous bizarre multinucleate giant cells and increased reticulin deposition. Compared with conventional isocitrate dehydrogenase (IDH)-wildtype glioblastomas, gcGBMs typically occur in younger patients and are generally associated with an improved prognosis. Although prior studies of gcGBMs have shown enrichment of genetic events, such as TP53 alterations, no defining aberrations have been identified. The aim of this study was to evaluate the genomic profile of gcGBMs to facilitate more accurate diagnosis and prognostication for this entity. METHODS: Through a multi-institutional collaborative effort, we characterized 10 gcGBMs by chromosome studies, single nucleotide polymorphism microarray analysis, and targeted next-generation sequencing. These tumors were subsequently compared to the genomic and epigenomic profile of glioblastomas described in The Cancer Genome Atlas (TCGA) dataset. RESULTS: Our analysis identified a specific pattern of genome-wide massive loss of heterozygosity (LOH) driven by near haploidization in a subset of glioblastomas with giant cell histology. We compared the genomic signature of these tumors against that of all glioblastomas in the TCGA dataset (n = 367) and confirmed that our cohort of gcGBMs demonstrated a significantly different genomic profile. Integrated genomic and histologic review of the TCGA cohort identified 3 additional gcGBMs with a near haploid genomic profile. CONCLUSIONS: Massive LOH driven by haploidization represents a defining molecular hallmark of a subtype of gcGBM. This unusual mechanism of tumorigenesis provides a diagnostic genomic hallmark to evaluate in future cases, may explain reported differences in survival, and suggests new therapeutic vulnerabilities.

Occurrence and characterization of medulloblastoma in a patient with Curry-Jones syndrome.

Medulloblastoma in a Patient with Curry-Jones Syndrome with a mosaic variant, c.1234C > T (p.Leu412Phe), in SMO.

Endobronchial Glomus Tumor in a Child.

Glomus tumors (GTs) are rare, usually benign, mesenchymal neoplasms typically located in the cutaneous tissues of the extremities. Visceral locations have been reported in ∼5% of cases. The average age at diagnosis is 42 years. GTs originating in the respiratory tract of pediatric patients are exceedingly rare. We report a 16-year-old male with a GT of the right lower lobe bronchus.

Determining IDH-Mutational Status in Gliomas Using IDH1-R132H Antibody and Polymerase Chain Reaction.

Determination of the isocitrate dehydrogenase (IDH) mutation status, presence or absence of mutation in IDH genes (IDH1 or IDH2), has become one of the most important molecular features taken into account in the management of patients with diffuse gliomas. Tumors that are IDH-mutant have a better prognosis than their counterparts with similar histologic grade and IDH-wildtype phenotype. IDH1-R132H is the most common IDH mutation, present in ~90% of IDH-mutant cases. This mutation yields an altered protein that can be detected by immunohistochemistry. We evaluated the IDH1-R132H antibody (clone H09) to determine IDH mutation status as the first line test and compared with the results of polymerase chain reaction (PCR) testing that can detect more types of mutations in IDH1 or IDH2. A total of 62 gliomas were evaluated: 30 glioblastomas (including 3 gliosarcomas), 11 grade III diffuse gliomas, 17 grade II diffuse gliomas, and 4 circumscribed gliomas. Twelve of 62 cases were IDH-mutant by immunohistochemistry and 15 of 62 by PCR. PCR detected the following mutations: IDH1-R132H (11 cases), IDH1-R132C (1 case), IDH2 R172, NOS (1 case), IDH1 R132, NOS (1 case), and IDH2-R172K (1 case). The R132H antibody had high specificity (100%) and sensitivity (80%) to detect IDH mutation status; the discordant results were 3 false-negatives. IDH-R132H immunostain is suitable as a first line test. Nonimmunoreactive cases could be studied by PCR following recommendations of the 2016 World Health Organization guidelines.

YAP and the Hippo pathway in pediatric cancer.

The Hippo pathway is an important signaling pathway that controls cell proliferation and apoptosis. It is evolutionarily conserved in mammals and is stimulated by cell-cell contact, inhibiting cell proliferation in response to increased cell density. During early embryonic development, the Hippo signaling pathway regulates organ development and size, and its functions result in the coordinated balance between proliferation, apoptosis, and differentiation. Its principal effectors, YAP and TAZ, regulate signaling by the embryonic stem cells and determine cell fate and histogenesis. Dysfunction of this pathway contributes to cancer development in adults and children. Emerging studies have shed light on the upregulation of Hippo pathway members in several pediatric cancers and may offer prognostic information on rhabdomyosarcoma, osteosarcoma, Wilms tumor, neuroblastoma, medulloblastoma, and other brain gliomas. We review the results of such published studies and highlight the potential clinical application of this pathway in pediatric oncologic and pathologic studies. These studies support targeting this pathway as a novel treatment strategy.

Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.

Clinical, Pathological, and Surgical Outcomes for Adult Pineoblastomas.

INTRODUCTION: Pineoblastomas are uncommon primitive neuroectodermal tumors that occur mostly in children; they are exceedingly rare in adults. Few published reports have compared the various aspects of these tumors between adults and children. METHODS: The authors report a series of 12 pineoblastomas in adults from 2 institutions over 24 years. The clinical, radiologic, and pathologic features and clinical outcomes were compared with previously reported cases in children and adults. RESULTS: Patient age ranged from 24 to 81 years, and all but 1 patient exhibited symptoms of obstructive hydrocephalus. Three patients underwent gross total resection, and subtotal resection was performed in 3 patients. Diagnostic biopsy specimens were obtained in an additional 6 patients. Pathologically, the tumors had the classical morphologic and immunohistochemical features of pineoblastomas. Postoperatively, 10 patients received radiotherapy, and 5 patients received chemotherapy. Compared with previously reported cases, several differences were noted in clinical outcomes. Of the 12 patients, only 5 (42%) died of their disease (average length of survival, 118 months); 5 patients (42%) are alive with no evidence of disease (average length of follow-up, 92 months). One patient died of unrelated causes, and one was lost to follow-up. Patients with subtotal resections or diagnostic biopsies did not suffer a worse prognosis. Of the 9 patients with biopsy or subtotal resection, 4 are alive, 4 died of their disease, and 1 died of an unrelated hemorrhagic cerebral infarction. CONCLUSIONS: Although this series is small, the data suggest that pineoblastomas in adults have a less aggressive clinical course than in children.

A unique case of ovarian psammocarcinoma with mediastinal, pulmonary, subcutaneous, and omental metastases.

Psammocarcinoma is a rare form of serous ovarian and peritoneal carcinoma, characterized by abundant psammoma bodies, invasiveness, and low-grade cytological features. Many of the cases which have been reported had extraovarian spread and peritoneal seeding at the time of presentation. We present a case of 45-year-old woman with ovarian psammocarcinoma who initially presented with a metastatic subcutaneous nodule, and was found to have pulmonary and mediastinal metastases. We believe this to be the first report of a psammocarcinoma with these metastases. Ovarian and peritoneal psammocarcinomas are quite rare, and because of this, knowledge of their behavior is limited. Although most seem to follow an indolent course similar to that of borderline lesions of the ovary, this case demonstrates that some of these tumors may be clinically aggressive with distant metastases.