Intraocular medulloepithelioma: an unusual and challenging entity in paediatric population.

Intraocular medulloepithelioma is a rare, congenital tumour of the non-pigmented ciliary epithelium. It most frequently arises from the ciliary body but can also have its origin from the retina, iris and optic nerve. The age when lesion first appears is typically around 2-10 years. Nearly 50-60% of patients having this lesion may also have secondary features such as cataract and neovascular glaucoma. Those with extrascleral medulloepithelioma are at risk for metastasis. Systemic correlation of the tumour with pleuropulmonary blastoma/DICER1 gene is reported in the literature. Here, we report a case of a 15 years old boy with one year history of right eye proptosis and painful red right eye along with decreased vision for one week. He was assessed and operated for cataract elsewhere three years back. The ophthalmology team managed him for endophthalmitis with intravenous antibiotics, followed by 2 sessions of cryotherapy and finally an enucleation of right eye was performed due to severe pain and no vision in the involved eye. His left eye, general physical examination and systemic evaluation were normal. Histopathology revealed the diagnosis of 'malignant teratoid medulloepithelioma'. Therefore, evaluation of systemic associations for DICER1 gene mutations was performed by the oncology team. For high risk feature of scleral invasion on histopathology, he was treated with chemotherapy. Since the tumour is of rare occurrence; an international expert team with vast research experience in PPB/DICER1 associated tumours was also contacted. He was registered in International PPB/DICER1 registry where a detailed central radiology and pathology review was performed. Genetic counseling and surveillance plan was also suggested by the international registry.

Metabolism of pancreatic neuroendocrine tumors: what can omics tell us?

Introduction: Reprogramming of cellular metabolism is now a hallmark of tumorigenesis. In recent years, research on pancreatic neuroendocrine tumors (pNETs) has focused on genetic and epigenetic modifications and related signaling pathways, but few studies have been devoted to characterizing the metabolic profile of these tumors. In this review, we thoroughly investigate the metabolic pathways in pNETs by analyzing the transcriptomic and metabolomic data available in the literature. Methodology: We retrieved and downloaded gene expression profiles from all publicly available gene set enrichments (GSE43797, GSE73338, and GSE117851) to compare the differences in expressed genes based on both the stage and MEN1 mutational status. In addition, we conducted a systematic review of metabolomic data in NETs. Results: By combining transcriptomic and metabolomic approaches, we have identified a distinctive metabolism in pNETs compared with controls without pNETs. Our analysis showed dysregulations in the one-carbon, glutathione, and polyamine metabolisms, fatty acid biosynthesis, and branched-chain amino acid catabolism, which supply the tricarboxylic acid cycle. These targets are implicated in pNET cell proliferation and metastasis and could also have a prognostic impact. When analyzing the profiles of patients with or without metastasis, or with or without MEN1 mutation, we observed only a few differences due to the scarcity of published clinical data in the existing research. Consequently, further studies are now necessary to validate our data and investigate these potential targets as biomarkers or therapeutic solutions, with a specific focus on pNETs.

Embryonal Tumors of the Central Nervous System with Multilayered Rosettes and Atypical Teratoid/Rhabdoid Tumors.

The 2016 WHO classification of tumors of the central nervous system affected importantly the group of CNS embryonal tumors. Molecular analysis on methylome, genome, and transcriptome levels allowed better classification, identification of specific molecular hallmarks of the different subtypes of CNS embryonal tumors, and their more precise diagnosis. Routine application of appropriate molecular testing and standardized reporting are of pivotal importance for adequate prognosis and treatment, but also for epidemiology studies and search for efficient targeted therapies. As a result of this approach, the term primitive neuroectodermal tumor-PNET was removed and a new clinic-pathological entity was introduced-Embryonal tumor with multilayered rosettes (ETMR). The group of CNS embryonal tumors include also medulloblastoma, medulloepithelioma, CNS neuroblastoma, CNS ganglioneuroblastoma, atypical teratoid/rhabdoid tumor (ATRT) and their subtypes. This chapter will focus mainly on ETMR and ATRT. Embryonal tumors with multilayered rosettes and the atypical teratoid/rhabdoid tumors are undifferentiated or poorly differentiated tumors of the nervous system that originate from primitive brain cells, develop exclusively in childhood or adolescence, and are characterized by a high degree of malignancy, aggressive evolution and a tendency to metastasize to the cerebrospinal fluid. Their clinical presentation is similar to other malignant, intracranial, neoplastic lesions and depends mainly on the localization of the tumor, the rise of the intracranial pressure, and eventually the obstruction of the cerebrospinal fluid pathways. The MRI image characteristics of these tumors are largely overlappingintra-axial, hypercellular, heterogeneous tumors, frequently with intratumoral necrosis and/or hemorrhages. Treatment options for ETMR and ATRT are very restricted. Surgery can seldom achieve radical excision. The rarity of the disease hampers the establishment of a chemotherapy protocol and the usual age of the patients limits severely the application of radiotherapy as a therapeutic option. Consequently, the prognosis of these undifferentiated, malignant, aggressive tumors remains dismal with a 5-year survival between 0 and 30%.

Brain and Spinal Cord Tumors of Embryonic Origin.

Embryonal tumors (ETs) of the central nervous system (CNS) comprise a large heterogeneous group of highly malignant tumors that predominantly affect children and adolescents. Currently, the neoplasms classified as ET are the medulloblastoma (MB), embryonal tumors with multilayered rosettes (ETMR), medulloepithelioma (ME), CNS neuroblastoma (NB), CNS ganglioneuroblastoma (GNB), atypical teratoid/rhabdoid tumors (AT/RT), and CNS embryonal tumors with rhabdoid features. All these tumors are classified as malignant-grade IV neoplasms, and the prognosis of patients with these neoplasms is very poor. Currently, except for the histological classification of MB, the recently utilized WHO classification accepts a novel molecular classification of MBs into four distinct molecular subgroups: wingless/integrated (WNT)-activated, sonic hedgehog (Shh), and the numerical Group3 and Group 4. The combination of both histological and genetic classifications has substantial prognostic significance, and patients are categorized as low risk with over 90% survival, the standard risk with 75-90% survival, high risk with 50-75% survival, and very high risk with survival rate lower than 50%. Children under three years are predominantly affected by AT/RT and represent about 20% of all CNS tumors in this age group. AT/RT is typically located in the posterior fossa (mainly in cerebellopontine angle) in 50-60% of the cases. The pathogenesis of this neoplasm is strongly associated with loss of function of the SMARCB1 (INI1, hSNF5) gene located at the 22q11.23 chromosome, or very rarely with alterations in (SMARCA4) BRG1 gene. The cells of this neoplasm resemble those of other neuronal tumors, and hence, immunochemistry markers have been utilized, such as smooth muscle actin, epithelial membrane antigen, vimentin, and lately antibodies for INI1. ETMRs are characterized by the presence of ependymoblastic rosettes formed by undifferentiated neuroepithelial cells and neuropil. The tumorigenesis of ETMRs is strongly related to the amplification of the pluripotency factor Chr19q13.41 miRNA cluster (C19MC) present in around 90% of the cases. Additionally, the expression of LIN28A is a highly sensitive and specific marker of ETMR diagnosis, as it is overexpressed in almost all cases of ETMR and is related to poor patient outcomes. The treatment of patients with ETs includes a combination of surgical resection, radiotherapy (focal or craniospinal), and chemotherapeutic agents. Currently, there is a trend to reduce the dose of craniospinal irradiation in the treatment of low-risk MBs. Novel targeted therapies are expected in the treatment of patients with MBs due to the identification of the main driver genes. Survival rates vary between ET types and their subtypes, with ganglioneuroblastoma having over 95% 5-year survival rate, while ATRT is probably linked with the worst prognosis with a 30% 5-year survival rate.

Clinicopathological and molecular characterization of a case classified by DNA­methylation profiling as "CNS embryonal tumor with BRD4-LEUTX fusion".

Central Nervous System (CNS) embryonal tumors represent a heterogeneous group of highly aggressive tumors occurring preferentially in children but also described in adolescents and adults. In 2021, the CNS World Health Organization (WHO) classification drastically changed the diagnosis of the other CNS embryonal tumors including new histo-molecular tumor types. Here, we report a pediatric case of a novel tumor type among the other CNS embryonal tumors classified within the methylation class "CNS Embryonal Tumor with BRD4-LEUTX Fusion". The patient was a 4-year girl with no previous history of disease. For a few weeks, she suffered from headaches, vomiting and mild fever associated with increasing asthenia and loss of weight leading to a global deterioration of health. MRI brain examination revealed a large, grossly well-circumscribed tumoral mass lesion located in the left parietal lobe, contralateral hydrocephalus and midline shift. Microscopic examination showed a highly cellular tumor with a polymorphic aspect. The majority of the tumor harbored neuroectodermal features composed of small cells with scant cytoplasm and hyperchromatic nuclei associated with small "medulloblastoma-like" cells characterized by syncytial arrangement and focally a streaming pattern. Tumor cells were diffusely positive for Synaptophysin, CD56, INI1 and SMARCA4 associated with negativity for GFAP, OLIG-2, EMA, BCOR, LIN28A and MIC-2. Additional IHC features included p53 protein expression in more than 10% of the tumor's cells and very interestingly, loss of H3K27me3 expression. The Heidelberg DNA-methylation classifier classified this case as "CNS Embryonal Tumor with BRD4:LEUTX Fusion". RNA-sequencing analyses confirmed the BRD4 (exon 13)-LEUTX (exon 2) fusion with no other molecular alterations found by DNA sequencing. Our case report confirmed that a new subgroup of CNS embryonal tumor with high aggressive potential, loss of H3K27me3 protein expression, BRDA4-LEUTX fusion, named "Embryonal CNS tumor with BRD4-LEUTX fusion", has to be considered into the new CNS WHO classification.

Supratentorial CNS-PNETs in children; a Swedish population-based study with molecular re-evaluation and long-term follow-up.

BACKGROUND: Molecular analyses have shown that tumours diagnosed as supratentorial primitive neuro-ectodermal tumours of the central nervous system (CNS-PNETs) in the past represent a heterogenous group of rare childhood tumours including high-grade gliomas (HGG), ependymomas, atypical teratoid/rhabdoid tumours (AT/RT), CNS neuroblastoma with forkhead box R2 (FOXR2) activation and embryonal tumour with multi-layered rosettes (ETMR). All these tumour types are rare and long-term clinical follow-up data are sparse. We retrospectively re-evaluated all children (0-18 years old) diagnosed with a CNS-PNET in Sweden during 1984-2015 and collected clinical data. METHODS: In total, 88 supratentorial CNS-PNETs were identified in the Swedish Childhood Cancer Registry and from these formalin-fixed paraffin-embedded tumour material was available for 71 patients. These tumours were histopathologically re-evaluated and, in addition, analysed using genome-wide DNA methylation profiling and classified by the MNP brain tumour classifier. RESULTS: The most frequent tumour types, after histopathological re-evaluation, were HGG (35%) followed by AT/RT (11%), CNS NB-FOXR2 (10%) and ETMR (8%). DNA methylation profiling could further divide the tumours into specific subtypes and with a high accuracy classify these rare embryonal tumours. The 5 and 10-year overall survival (OS) for the whole CNS-PNET cohort was 45% ± 12% and 42% ± 12%, respectively. However, the different groups of tumour types identified after re-evaluation displayed very variable survival patterns, with a poor outcome for HGG and ETMR patients with 5-year OS 20% ± 16% and 33% ± 35%, respectively. On the contrary, high PFS and OS was observed for patients with CNS NB-FOXR2 (5-year 100% for both). Survival rates remained stable even after 15-years of follow-up. CONCLUSIONS: Our findings demonstrate, in a national based setting, the molecular heterogeneity of these tumours and show that DNA methylation profiling of these tumours provides an indispensable tool in distinguishing these rare tumours. Long-term follow-up data confirms previous findings with a favourable outcome for CNS NB-FOXR2 tumours and poor chances of survival for ETMR and HGG.

Embryonal tumor with multilayered rosettes: Post-treatment maturation and implications for future therapy.

BACKGROUND: Embryonal tumor with multilayered rosettes (ETMR) is a deadly grade IV pediatric brain tumor. Despite an intensive multimodal treatment approach that includes surgical resection, high-dose chemotherapy, and radiotherapy, the progression-free survival at 5 years is less than 30%. CASE: We report a case of long-term survival in a 5-month old female with a large mass in the posterior fossa, diagnosed as ETMR, which subsequently underwent treatment-induced maturation. Prior to chemotherapy, histopathology revealed an abundance of highly proliferative, undifferentiated cells and multilayered rosette structures. Conversely, post-treatment histopathology revealed cell populations that differentiated into neuronal and ganglionic phenotypes. At 5-year follow-up, the patient remains progression-free. CONCLUSION: This finding contributes to the few reports to date of post-treatment differentiation/maturation of ETMR cell populations, with an implication for less cytotoxic therapeutic interventions aimed at differentiation.

Epigenetic age acceleration among survivors of pediatric medulloblastoma and primitive neuroectodermal tumor.

Survivors of childhood central nervous system (CNS) tumors experience early-onset aging-related phenotypes. DNA methylation (DNAm) age is an emerging epigenetic biomarker of physiologic age and may be predictive of chronic health conditions in long-term survivors. This report describes the course of epigenetic age acceleration using post-diagnosis blood samples (median: 3.9 years post-diagnosis; range: 0.04-15.96) from 83 survivors of pediatric CNS tumors. Epigenetic age acceleration was detected in 72% of patients, with an average difference between chronologic and DNAm age of 2.58 years (95% CI: 1.75-3.41, p < 0.001). Time from diagnosis to sample collection correlated with the magnitude of epigenetic age acceleration.

Amplification of the PLAG-family genes-PLAGL1 and PLAGL2-is a key feature of the novel tumor type CNS embryonal tumor with PLAGL amplification.

Pediatric central nervous system (CNS) tumors represent the most common cause of cancer-related death in children aged 0-14 years. They differ from their adult counterparts, showing extensive clinical and molecular heterogeneity as well as a challenging histopathological spectrum that often impairs accurate diagnosis. Here, we use DNA methylation-based CNS tumor classification in combination with copy number, RNA-seq, and ChIP-seq analysis to characterize a newly identified CNS tumor type. In addition, we report histology, patient characteristics, and survival data in this tumor type. We describe a biologically distinct pediatric CNS tumor type (n = 31 cases) that is characterized by focal high-level amplification and resultant overexpression of either PLAGL1 or PLAGL2, and an absence of recurrent genetic alterations characteristic of other pediatric CNS tumor types. Both genes act as transcription factors for a regulatory subset of imprinted genes (IGs), components of the Wnt/ß-Catenin pathway, and the potential drug targets RET and CYP2W1, which are also specifically overexpressed in this tumor type. A derived PLAGL-specific gene expression signature indicates dysregulation of imprinting control and differentiation/development. These tumors occurred throughout the neuroaxis including the cerebral hemispheres, cerebellum, and brainstem, and were predominantly composed of primitive embryonal-like cells lacking robust expression of markers of glial or neuronal differentiation (e.g., GFAP, OLIG2, and synaptophysin). Tumors with PLAGL1 amplification were typically diagnosed during adolescence (median age 10.5 years), whereas those with PLAGL2 amplification were diagnosed during early childhood (median age 2 years). The 10-year overall survival was 66% for PLAGL1-amplified tumors, 25% for PLAGL2-amplified tumors, 18% for male patients, and 82% for female patients. In summary, we describe a new type of biologically distinct CNS tumor characterized by PLAGL1/2 amplification that occurs predominantly in infants and toddlers (PLAGL2) or adolescents (PLAGL1) which we consider best classified as a CNS embryonal tumor and which is associated with intermediate survival. The cell of origin and optimal treatment strategies remain to be defined.

Malignant teratoid intraocular ciliary body medulloepithelioma in a 5-year-old male with corresponding somatic copy number alteration profile of aqueous humor cell-free DNA.

BACKGROUND: Intraocular, ciliary body, medulloepithelioma (CBME) is a rare tumor of the nonpigmented ciliary body epithelium, typically presenting in childhood. We describe a case of CBME. MATERIALS AND METHODS: Ocular examination and imaging guided diagnostic and treatment decisions. Aqueous humor (AH) liquid biopsy was collected from the affected eye at eventual enucleation. Whole genome sequencing (WGS) was employed to determine somatic copy number alterations (SCNA) in AH cell-free DNA (cfDNA). Tumor sample was analyzed using various assays to evaluate for oncogenic mutations and SCNAs. Histopathology determined diagnosis. RESULTS: A 5-year-old male with glaucoma and cataract in the left eye (OS) experienced worsening left eye pain and redness. There was no light perception OS and the eye was hypotonus. Anterior segment exam showed complete cataract and rubeosis iridis. Ocular B-scan ultrasound OS revealed an intraocular lesion with calcifications and retinal detachment. Orbital MRI suggested left globe hypercellularity. An infiltrative lesion involving the ciliary body was seen in the left eye on examination under anesthesia. Left eye enucleation was performed in the setting of pain, blindness, and tumor, with anterior chamber paracentesis for AH liquid biopsy collection. SCNA profile of AH cfDNA demonstrated loss of copy of chromosomes 4, 6, and 9. Tumor was negative for clinically significant mutations or SCNAs. Histopathology diagnosed malignant teratoid CBME. CONCLUSIONS: We present a case of CBME and include the unique SCNA profile of AH cfDNA from the enucleated eye. This case suggests utility of AH liquid biopsy in distinguishing between differential diagnoses for intraocular mass lesions.

A rare radiotherapy-sensitive primitive neuroectodermal tumor with APC gene amplification in an adult: a case report and literature review.

Primitive neuroectodermal tumor (PNET) of the lung is rare in adults, and treatment options vary. We herein describe the disease course and follow-up of PNET in an adult. A 27-year-old man was admitted to our hospital because of cough and headache, and whole-exome sequencing revealed positive expression of the EWSR1-FLI1 fusion gene and amplification of the APC gene. Although the patient received multidisciplinary treatment including chemotherapy regimens of etoposide plus cisplatin; focal radiotherapy focusing on the cerebrum, lung, and kidneys; and a subsequent palliative gastrointestinal operation, he eventually died of multiple organ functional failure. His overall survival period was 18 months, and his progression-free survival period was 4 months. During the treatment, the patient showed remarkable sensitivity to radiotherapy. In conclusion, PNET of the lung in adult patients is extremely rare, and the prognosis is very poor. Involvement of a multidisciplinary team in the development of personalized therapeutic strategies is essential. This patient with APC gene amplification showed excellent sensitivity to radiotherapy for intrapulmonary and intracranial lesions, suggesting that APC gene amplification may be related to radiotherapy sensitivity. However, further clinical research is needed.

Neuroectodermal Rosettes in Immature Teratomas Are Not the Counterpart of Embryonal Tumours With Multilayered Rosettes.

BACKGROUND/AIM: Immature teratomas (IMT) are malignant germ cell tumours composed of immature embryonal tissue, mostly neuroectodermal tubules and rosettes. Meanwhile, embryonal tumours with multilayered rosettes (ETMR) are aggressive central nervous system tumours composed of neurocyte proliferation with rosette formation. The histopathological appearance of rosette formation in ETMR is the same as that in IMT. Recently, 19q13.42 amplification was reported as a specific genetic marker of ETMR. The aim of this study was to compare ETMR with IMT from histological, immunohistochemical and genetic perspectives. MATERIALS AND METHODS: We retrospectively analysed tumour samples from 48 patients with IMT and 1 patient with ETMR. We performed fluorescence in situ hybridization (FISH) analysis, which revealed amplification of the 19q13.42 locus in the ETMR case. In addition, immunohistochemical analyses of LIN28A, ß-catenin and p53 were performed. RESULTS: In FISH analysis all 48 cases of IMT showed diploidy. By immunohistochemical analysis, LIN28A expression was observed in 54% of IMT cases (25/48 cases) and in the ETMR case. Nuclear staining of ß-catenin was observed in 33% of IMT cases (16/48 cases). Meanwhile, aberrant expression of p53 was not identified in IMT nor ETMR cases. CONCLUSION: Genetic changes associated with IMT differ from those in ETMR, but LIN28A protein immunohistochemical expression, which is specific for ETMR, can be a biomarker for the immature neuroepithelial component in IMT.

Analysis of polymorphisms in EGF, EGFR and HER2 genes in pancreatic neuroendocrine tumors (PNETs).

OBJECTIVES: Pancreatic neuroendocrine tumors (NETs) are rare and account for about 7% of all cancers occurring in the pancreas. The epidermal growth factor family of receptors and their ligands play an important role in the growth and progression of tumors but their role in PNET development remains unknown. We hypothesized that functional single nucleotide polymorphisms (SNPs) in the EGF, EGFR, and HER2 genes might affect individual susceptibility to PNETs development and invasion like it was shown for various other tumors. METHODS: We genotyped 68 patients with unresectable PNETs and 300 controls to evaluate the association between EGF, EGFR, and HER2 polymorphisms and susceptibility to PNETs and presence of metastases. RESULTS: Genotype analysis of three SNPs EGF +61A/G (rs4444903), EGFR +1562 G/A (rs11543848), and HER2 +1963 A/G (rs1136201) showed that carriers of EGFR +1562 AG genotype and AA/AG EGF +61/HER2 +1963 genotype combination are at risk of developing PNET. Furthermore, EGFR +1562 AA genotype could be associated with the susceptibility to insulinoma development. CONCLUSIONS: Our results suggest involvement of EGFR signaling pathway in etiology of PNET development.

[Embryonal tumor with multilayered rosettes (ETMR): case report and literature review]. / Embrional'naya opukhol' s mnogosloinymi rozetkami (embryonal tumor with multilayered rosettes ­ ETMR): sluchai iz praktiki i obzor literatury.

Embryonal tumor with multilayered rosettes (ETMR) is a rare and highly malignant brain tumor that develops in children younger 4 years old. This neoplasm is characterized by extremely aggressive course, low sensitivity to chemotherapy and radiotherapy. Thanks to the progress of pathologists, diagnosis of ETMR is now available using immunohistochemical examination with LIN28A and SALL4 antibodies. Moreover, detection of microRNA amplification in the 19q13.42 locus by fluorescent hybridization in situ allows an unmistakable diagnosis.The authors describe clinical course and treatment outcome in a 2-year-old patient with a giant tumor of the right parietotemporal region. Postoperative histological examination verified ETMR. Despite adjuvant treatment, we observed fast progression of disease and unfavorable outcome after 5 months. Case report is supplemented by literature review. CONCLUSION: ETMR is very rare and poorly understood neoplasm. The authors present a giant hemispheric ETMR in a 2-year-old boy with an extremely aggressive course of disease. Despite the advances in diagnosis and treatment of CNS tumors in children, there are currently more questions than answers regarding ETMR. Pooled analysis of all available data with large-scale studies is needed. It is necessary to emphasize an exceptional role of each clinical case for global study of this tumor. Timely adjuvant/neoadjuvant therapy in highly specialized centers is also essential.

Spectrum of paired-like homeobox 2b immunoexpression in pediatric brain tumors with embryonal morphology.

Paired-like homeobox 2b (PHOX2B) is an established immunomarker for peripheral neuroblastoma and autonomic nervous system cells. We aimed to evaluate the utility of PHOX2B immunostaining in central nervous system (CNS) tumors with embryonal morphology. Fifty-one tumors were stained with PHOX2B and submitted for whole slide image analysis: 35 CNS tumors with embryonal morphology (31 CNS embryonal tumors and four gliomas); and 16 peripheral neuroblastomas were included for comparison. Diffuse nuclear immunopositivity was observed in all (16/16) neuroblastomas (primary and metastatic). Among CNS embryonal tumors, focal immunoreactivity for PHOX2B was observed in most (5/7) embryonal tumors with multilayered rosettes (ETMR) and a single high-grade neuroepithelial tumor (HGNET) with PLAGL2 amplification; the remaining 27 CNS tumors were essentially immunonegative (<0.05% positive). Among ETMR, PHOX2B expression was observed in a small overall proportion (0.04%-4.94%) of neoplastic cells but focally reached up to 39% in 1 mm 'hot spot' areas. In the PLAGL2-amplified case, 0.09% of the total neoplastic population was immunoreactive, with 0.53% in the 'hot spot' area. Care should be taken in interpreting PHOX2B immunopositivity in a differential diagnosis that includes metastatic neuroblastoma and CNS tumors; focal or patchy expression should not be considered definitively diagnostic of metastatic peripheral neuroblastoma.

Embryonal tumors in the WHO CNS5 classification: A Review.

Embryonal tumors are a heterogenous group of neoplasms mostly defined by recurrent genetic driver events. They have been, previously, broadly classified as either medulloblastoma or supratentorial primitive neuroectodermal tumors (PNETs). However, the application of DNA methylation/gene expression profiling in large series of neoplasms histologically defined as PNET, revealed tumors, which showed genetic events associated with glial tumors. These findings led to the definitive removal of the term "PNET" in the 2016 World Health Organization (WHO) classification of CNS tumors. Moreover, further studies on a large scale of methylation profiling have allowed the identification of new molecular-defined entities and have largely influenced the 5th edition of the WHO classification of CNS tumors (WHO CNS5) for both medulloblastomas and other CNS embryonal tumors. The importance of molecular characteristics in CNS embryonal tumors is well represented by the identification of different molecular groups and subgroups in medulloblastoma. So, in the CNS5, the emerged group 3 and group 4 belong to the classification, and the four molecular and morphologic types are now combined into a unique section. Among other embryonal tumors, two new recognized entities are introduced in CNS5: CNS neuroblastoma, FOXR2-activated, and CNS tumor with BCOR internal tandem duplication (ITD). Embryonal tumor with multilayered rosettes (ETMR), already present in the previous classification now has a revised nomenclature as a result of the new DICER1 alteration, additional to the formerly known C19MC. Regarding atypical teratoid/rhabdoid tumor (AT/RT), three molecular subgroups are recognized in CNS5. The combination of histopathological and molecular features reflects the complexity of all these tumors and gives critical information in terms of prognosis and therapy. This encourages the use of a layered diagnostic report with the integrated diagnosis at the top, succeeded by layers including the histological, molecular, and other essential details.

Predicting Novel Drug Candidates for Pancreatic Neuroendocrine Tumors via Gene Signature Comparison and Connectivity Mapping.

INTRODUCTION: There is a paucity of effective treatment options for advanced pancreatic neuroendocrine tumors (pNETs). Genome-wide analyses may allow for potential drugs to be identified based on differentially expressed genes (DEGs). METHODS: Oligo microarray data of RNA expression profiling of pNETs and normal pancreas tissues were downloaded from the Gene Expression Omnibus. Functional and pathway enrichment information of the DEGs was obtained using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Corresponding homologous proteins were analyzed and potential therapeutic drugs for pNETs were identified using the Connectivity Map and Drug-Gene Interaction Database. RESULTS: Assessment of raw data from 12,610 pNET genes demonstrated that 1082 and 380 genes were upregulated and downregulated, respectively, compared with normal pancreas tissue. Upregulated pathways were associated with nitrogen metabolism (i.e., GABAergic synapse, and graft-versus-host disease), whereas downregulated pathways included C-type leptin receptor signaling pathway, pertussis and AMPK signaling pathway. In particular, the protein-protein interaction analysis revealed 10 upregulated hub genes (DYNLL1, GNB5, GNB2, GNG4, GNAI2, GNAI1, HIST2H2BE, NUP107, NUP133, and SNAP25) and 10 downregulated hub genes (CXCL8, F2, CXCL2, GCG, SST, INS, GALR3, CCL20, ADRA2B, and CXCL6). Using the Drug-Gene Interaction Database, candidate drugs for pNETs treatment included 3 EGFR inhibitors (canertinib, erlotinib, WZ-4-145), as well as other cell-signaling pathway inhibitors such as AG-592, acarbose, lonidamine, azacytidine, rottlerin, and HU-211. CONCLUSION: Using available genetic atlas data, potential drug candidates for treatment of pNETs were identified based on differentially expressed genes. These results may help focus efforts on identifying targeted agents with therapeutic efficacy to treat patients with pNETs.

Primary EWS/PNET of the lung with TP53 germline and SKT11 somatic mutation: A case report and review of the literature.

Primary pulmonary EWS/PNET is extremely rare. This report describes a 20 year-old man with primary pulmonary EWS/PNET with TP53 germline and SKT11 somatic mutation. After four neoadjuvant chemotherapy cycles (VAC with alternating IE) combined with anlotinib, a left pneumonectomy was performed. Maintenance anlotinib monotherapy was then continued with no sign of recurrence to date. It is suggested that before the treatment and prognosis of children or young adults with primary EWS/PNET of the lung that consideration should be given to genetic testing.

Therapeutic implications of improved molecular diagnostics for rare CNS embryonal tumor entities: results of an international, retrospective study.

BACKGROUND: Only few data are available on treatment-associated behavior of distinct rare CNS embryonal tumor entities previously treated as "CNS-primitive neuroectodermal tumors" (CNS-PNET). Respective data on specific entities, including CNS neuroblastoma, FOXR2 activated (CNS NB-FOXR2), and embryonal tumors with multilayered rosettes (ETMR) are needed for development of differentiated treatment strategies. METHODS: Within this retrospective, international study, tumor samples of clinically well-annotated patients with the original diagnosis of CNS-PNET were analyzed using DNA methylation arrays (n = 307). Additional cases (n = 66) with DNA methylation pattern of CNS NB-FOXR2 were included irrespective of initial histological diagnosis. Pooled clinical data (n = 292) were descriptively analyzed. RESULTS: DNA methylation profiling of "CNS-PNET" classified 58 (19%) cases as ETMR, 57 (19%) as high-grade glioma (HGG), 36 (12%) as CNS NB-FOXR2, and 89(29%) cases were classified into 18 other entities. Sixty-seven (22%) cases did not show DNA methylation patterns similar to established CNS tumor reference classes. Best treatment results were achieved for CNS NB-FOXR2 patients (5-year PFS: 63% ± 7%, OS: 85% ± 5%, n = 63), with 35/42 progression-free survivors after upfront craniospinal irradiation (CSI) and chemotherapy. The worst outcome was seen for ETMR and HGG patients with 5-year PFS of 18% ± 6% and 22% ± 7%, and 5-year OS of 24% ± 6% and 25% ± 7%, respectively. CONCLUSION: The historically reported poor outcome of CNS-PNET patients becomes highly variable when tumors are molecularly classified based on DNA methylation profiling. Patients with CNS NB-FOXR2 responded well to current treatments and a standard-risk CSI-based regimen may be prospectively evaluated. The poor outcome of ETMR across applied treatment strategies substantiates the necessity for evaluation of novel treatments.

Glioblastomas with primitive neuronal component harbor a distinct methylation and copy-number profile with inactivation of TP53, PTEN, and RB1.

Glioblastoma IDH-wildtype presents with a wide histological spectrum. Some features are so distinctive that they are considered as separate histological variants or patterns for the purpose of classification. However, these usually lack defined (epi-)genetic alterations or profiles correlating with this histology. Here, we describe a molecular subtype with overlap to the unique histological pattern of glioblastoma with primitive neuronal component. Our cohort consists of 63 IDH-wildtype glioblastomas that harbor a characteristic DNA methylation profile. Median age at diagnosis was 59.5 years. Copy-number variations and genetic sequencing revealed frequent alterations in TP53, RB1 and PTEN, with fewer gains of chromosome 7 and homozygous CDKN2A/B deletions than usually described for IDH-wildtype glioblastoma. Gains of chromosome 1 were detected in more than half of the cases. A poorly differentiated phenotype with frequent absence of GFAP expression, high proliferation index and strong staining for p53 and TTF1 often caused misleading histological classification as carcinoma metastasis or primitive neuroectodermal tumor. Clinically, many patients presented with leptomeningeal dissemination and spinal metastasis. Outcome was poor with a median overall survival of only 12 months. Overall, we describe a new molecular subtype of IDH-wildtype glioblastoma with a distinct histological appearance and genetic signature.