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This article discusses two novel tumors classified as extraventricular neurocytomas (EVN) that were found to have NTRK2 fusions instead of the usual FGFR1 alterations. The first case involved a 23-year-old woman with migraines and epileptic seizures, while the second case involved a 15-year-old girl with intracerebral calcifications. Both cases underwent total removal of the tumors and showed positive staining for synaptophysin and olig2. The study suggests that these findings have implications for diagnosis, therapy, and terminology, and further research is needed to better understand these tumors. [Extracted from the article]

The I CIC- i rearranged sarcoma was introduced into the 2021 World Health Organization (WHO) Classification of Tumours of the Central Nervous System (CNS), by homology of its soft-tissue counterpart.1 In the CNS, I CIC i fusions mainly implicate I DUX4 i or I NUTM1 i genes but non- I CIC i fusions (such as I ATXN1::DUX4 i and I ATXN1::NUTM1 i ) have been recently described.1-3 However, DNA-methylation profiling of all I CIC- i and non- I CIC- i fused CNS mesenchymal tumours showed that all cases clustered together.2 In soft tissue, it has been evidenced that whatever the fusion partner, the I CIC i translocation induces an oncogenic activation of the PEA3 family transcription factors, including ETV4.1 Consequently, ETV4 immunohistochemistry (IHC) may represent a specific biomarker for all I CIC- i rearranged sarcomas, whereas NUT immunoexpression is only observed in I CIC::NUTM1 i -fused sarcomas.1 In the CNS, the diagnosis of I CIC- i rearranged sarcoma may be challenging for neuropathologists, and a common diagnostic biomarker of all fusions may help to identify this rare tumour type. Our work is the first to evaluate the sensitivity and specificity of ETV4 in a large cohort of molecularly defined CNS tumours. ETV4 immunohistostaining is a sensitive and specific diagnostic biomarker for CIC-rearranged sarcoma of the central nervous system. [Extracted from the article]

Aim: Rosette‐forming glioneuronal tumour (RGNT) is a rare central nervous system (CNS) World Health Organization (WHO) grade 1 brain neoplasm. According to the WHO 2021, essential diagnostic criteria are a 'biphasic histomorphology with neurocytic and a glial component, and uniform neurocytes forming rosettes and/or perivascular pseudorosettes associated with synaptophysin expression' and/or DNA methylation profile of RGNT whereas 'FGFR1 mutation with co‐occurring PIK3CA and/or NF1 mutation' are desirable criteria. Material and methods: We report a series of 46 cases fulfilling the essential pathological diagnostic criteria for RGNT. FGFR1 and PIK3CA hotspot mutations were searched for by multiplexed digital PCR in all cases, whereas DNA methylation profiling and/or PIK3R1 and NF1 alterations were analysed in a subset of cases. Results: Three groups were observed. The first one included 21 intracranial midline tumours demonstrating FGFR1 mutation associated with PIK3CA or PIK3R1 (n = 19) or NF1 (n = 1) or PIK3CA and NF1 (n = 1) mutation. By DNA methylation profiling, eight cases were classified as RGNT (they demonstrated FGFR1 and PIK3CA or PIK3R1 mutations). Group 2 comprised 11 cases associated with one single FGFR1 mutation. Group 3 included six cases classified as low‐grade glioma (LGG) other than RGNT (one‐sixth showed FGFR1 mutation and one a FGFR1 and NF1 mutation) and eight cases without FGFR1 mutation. Groups 2 and 3 were enriched in lateral and spinal cases. Conclusions: We suggest adding FGFR1 mutation and intracranial midline location as essential diagnostic criteria. When DNA methylation profiling is not available, a RGNT diagnosis remains certain in cases demonstrating characteristic pathological features and FGFR1 mutation associated with either PIK3CA or PIK3R1 mutation. [ABSTRACT FROM AUTHOR]

Aims: We searched for recurrent pathological features and molecular alterations in a retrospective series of 72 low‐grade epilepsy‐associated neuroepithelial tumours (LEATs) with a prominent oligodendroglioma‐like component, in order to classify them according to the 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumours. Methods: Centralised pathological examination was performed as well as targeted molecular analysis of v‐Raf murine sarcoma viral oncogene homologue B (BRAF) and fibroblast growth factor receptor 1 (FGFR1) by multiplexed digital polymerase chain reaction (mdPCR). DNA methylation profiling was performed in cases with sufficient DNA. In cases with no genetic alteration by mdPCR and sufficient material, RNA sequencing was done. Results: We first reclassified our cohort into three groups: ganglioglioma (GG, n = 14), dysembryoplastic neuroepithelial tumours (DNTs, n = 19) and glioneuronal tumours/paediatric‐type low‐grade glioma (LGG) not otherwise specified (GNT/PLGG NOS, n = 39). mdPCR found an alteration in 38/72 cases. Subsequent RNA sequencing revealed a fusion transcript involving BRAF, FGFR1/2/3 or neurotrophic tyrosine kinase receptor type 2 [NTRK2] in 9/25 cases. DNA methylation profiling found 12/46 cases with a calibrated score ≥0.9. Unsupervised hierarchical clustering revealed two clusters: Cluster 1 was enriched with cases classified as DNT at histology, belonging to the LGG–DNT methylation class (MC), with haematopoietic progenitor cell antigen (CD34) negativity and FGRF1 alterations; Cluster 2 was enriched with cases classified at histology as GG, belonging to the LGG–GG MC MC, with BRAF V600E mutation and CD34 positivity. The tumours reclassified as GNT/PLGG NOS were equally distributed across both clusters. Interestingly, all polymorphous low‐grade neuroepithelial tumour of the young belonged to Cluster 2, whereas diffuse LGG mitogen‐activated protein kinase (MAPK) pathway‐altered were equally distributed among the two clusters. This led us to build an algorithm to classify LEATs with a prominent oligodendroglioma‐like component. Conclusions: Integrated histomolecular diagnosis of LEATs with a prominent oligodendroglioma‐like component remains challenging. Because these tumours can be split into two major clusters of biological significance, the clinicopathological relevance of the four types recognised by the WHO CNS5 within this spectrum of tumours is questionable. [ABSTRACT FROM AUTHOR]

FET:CREB fusions have been described in a variety of tumors from various phenotypes. Recently, these fusion transcripts were reported in intracranial tumors, variably named intracranial mesenchymal myxoid tumors or angiomatoid fibrous histiocytomas. Controversy remains concerning the terminology for these tumors. Here, we report 11 cases of central nervous system mesenchymal tumors with proven FET:CREB fusion. Most DNA methylation profiles were not classifiable using the Heidelberg Brain Tumor or Sarcoma Classifier (v11b4/v12.2). However, by using unsupervised t‐SNE and hierarchical clustering analyses, six of the cases constituted a distinct cluster. The remaining four tumors showed no obvious relation to any of the other referenced classes but were close to the clusters of extra‐CNS angiomatoid fibrous histiocytomas (n = 1), clear cell sarcomas (n = 1), or solitary fibrous tumors (n = 2). Our findings confirm that intracranial FET:CREB‐fused tumors do not represent a single molecular tumor entity, although most samples clustered close to each other, indicating the existence of a distinct epigenetic group that could potentially be partially masked by the low number of cases included. Further analyses are needed to characterize intracranial FET:CREB fused‐defined tumors in more detail. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze patients from two distinct families with a novel distal titinopathy phenotype associated with exactly the same CNV in the TTN gene. We used an integrated strategy combining deep phenotyping and complete molecular analyses in patients. The CNV is the most proximal out‐of‐frame TTN variant reported and leads to aberrant splicing transcripts leading to a frameshift. In this case, the dominant effect would be due to dominant‐negative and/or haploinsufficiency. Few CNV in TTN have been reported to date. Our data represent a novel phenotype–genotype association and provides hypotheses for its dominant effects. [ABSTRACT FROM AUTHOR]

We investigated the challenging diagnostic case of a ventricular cystic glioneuronal tumor with papillary features, by RNA sequencing using the Illumina TruSight RNA Fusion panel. We did not retrieve the SLC44A1‐PRKCA fusion gene specific for papillary glioneuronal tumor, but an EWSR1‐PATZ1 fusion transcript. RT‐PCR followed by Sanger sequencing confirmed the EWSR1‐PATZ1 fusion. It matched with canonic EWSR1 fusion oncogene, juxtaposing the entire N‐terminal transcriptional activation domain of EWSR1 gene and the C‐terminal DNA binding domain of a transcription factor gene, PATZ1. PATZ1 protein belongs to the BTB‐ZF (broad‐complex, tramtrack and bric‐à‐brac ‐zinc finger) family. It directly regulates Pou5f1 and Nanog and is essential to maintaining stemness by inhibiting neural differentiation. EWSR1‐PATZ1 fusion is a rare event in tumors: it was only reported in six round cell sarcomas and in three gliomas of three exclusively molecular studies. The first reported glioma was a BRAFV600E negative ganglioglioma, the second a BRAFV600E negative glioneuronal tumor, not otherwise specified and the third, very recently reported, a high grade glioma, not otherwise specified. In our study, forty BRAFV600E negative gangliogliomas were screened by FISH using EWSR1 break‐apart probes. We performed methylation profiling for the index case and for seven out of the ten FISH positive cases. The index case clustered apart from other pediatric low grade glioneuronal entities, and specifically from the well‐defined ganglioglioma methylation group. An additional pediatric intraventricular ganglioglioma clustered slightly more closely with ganglioglioma, but showed differences from the main ganglioglioma group and similarities with the index case. Both cases harbored copy number variations at the PATZ1 locus. EWSR1‐PATZ1 gene fusion might define a new type of glioneuronal tumors, distinct from gangliogliomas. [ABSTRACT FROM AUTHOR]

Adult glioblastomas, IDH‐wildtype represent a heterogeneous group of diseases. They are resistant to conventional treatment by concomitant radiochemotherapy and carry a dismal prognosis. The discovery of oncogenic gene fusions in these tumors has led to prospective targeted treatments, but identification of these rare alterations in practice is challenging. Here, we report a series of 30 adult diffuse gliomas with an in frame FGFR3‐TACC3 oncogenic fusion (n = 27 WHO grade IV and n = 3 WHO grade II) as well as their histological and molecular features. We observed recurrent morphological features (monomorphous ovoid nuclei, nuclear palisading and thin parallel cytoplasmic processes, endocrinoid network of thin capillaries) associated with frequent microcalcifications and desmoplasia. We report a constant immunoreactivity for FGFR3, which is a valuable method for screening for the FGFR3‐TACC3 fusion with 100% sensitivity and 92% specificity. We confirmed the associated molecular features (typical genetic alterations of glioblastoma, except the absence of EGFR amplification, and an increased frequency of CDK4 and MDM2 amplifications). FGFR3 immunopositivity is a valuable tool to identify gliomas that are likely to harbor the FGFR3‐TACC3 fusion for inclusion in targeted therapeutic trials. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Adipose derived stromal cells (ASCs) are abundant and easy to prepare. Such cells may be useful for treating severe vocal disturbance caused by acute vocal fold scars.Study Design: Prospective animal experiments with controls.Methods: Twenty New-Zealand white rabbits were used in the present study. We evaluated vocal fold healing, with or without injection of autologous ASCs, after acute scarring. A defined lesion was created and the ASCs were immediately injected. Vocal fold regeneration was evaluated histomorphometrically and via viscoelastic analysis using an electrodynamic shaker.Results: Six weeks after ASC injection, vocal folds exhibited significantly less inflammation than control folds (P < 0.005). In addition, hypertrophy of the lamina propria and fibrosis were significantly reduced upon ASC injection (P < 0.02). The decrease in viscoelastic parameters was less important in the ASC injected group compared to the noninjected group (P = 0.08).Conclusion: Injection of autologous ASCs improved vocal fold healing in our preclinical model. Further studies are needed, but this method may be useful in humans.Level Of Evidence: NA. Laryngoscope, 126:E278-E285, 2016. [ABSTRACT FROM AUTHOR]

Diffuse adult high-grade gliomas ( HGGs) with necrosis encompass anaplastic oligodendrogliomas ( AOs) with necrosis (grade III), glioblastomas ( GBM, grade IV) and glioblastomas with an oligodendroglial component ( GBMO, grade IV). Here, we aimed to search for prognostic relevance of histological classification and molecular alterations of these tumors. About 210 patients were included (63 AO, 56 GBM and 91 GBMO). GBMO group was split into 'anaplastic oligoastrocytoma ( AOA) with necrosis grade IV/GBMO,' restricted to tumors showing intermingled astrocytic and oligodendroglial component, and ' GBM/GBMO' based on tumors presenting oligodendroglial foci and features of GBM. Genomic arrays, IDH1 R132H expression analyses and IDH direct sequencing were performed. 1p/19q co-deletion characterized AO, whereas no IDH1 R132H expression and intact 1p/19q characterized both GBM and GBM/GBMO. AOA with necrosis/ GBMO mainly demonstrated IDH1 R132H expression and intact 1p/19q. Other IDH1 or IDH2 mutations were extremely rare. Both histological and molecular classifications were predictive of progression free survival (PFS) and overall survival (OS) ( P < 10−4). Diffuse adult HGGs with necrosis can be split into three histomolecular groups of prognostic relevance: 1p/19q co-deleted AO, IDH1 R132H- GBM and 1p/19q intact IDH1 R132H+ gliomas that might be classified as IDH1 R132H+ GBM. Because of histomolecular heterogeneity, we suggest to remove the name GBMO. [ABSTRACT FROM AUTHOR]

The article presents case studies of patients who developed paediatric glial and glioneuronal tumours due to BRAF V600E and H3F3A K27M mutations. The first patient had a large tumour in the pons and cerebellar hemisphere, the second patient had a large pineal tumour while the third patient had a glioma located in the brainstem.

Background Mammary analog secretory carcinoma ( MASC) of the salivary gland has been recently described according to morphological, immunohistochemical, and molecular ( ETV6- NTRK3 translocation) similarities with the mammary secretory carcinoma. The most important differential diagnostic considerations of MASC are low-grade adenocarcinoma not otherwise specified ( NOS), cystadenocarcinoma, and acinic cell carcinoma (Aci CC). These tumors may share an overlapping morphology with MASC, and additional immunohistochemical studies are required to reinforce the diagnosis. Mammaglobin, GCDFP-15, and p63 staining have been reported in MASC. Our study was designed to check the specificity of these antibodies in MASC compared to other frequent tumors of salivary glands. Methods A series of 62 salivary gland tumors [10 MASCs, 5 adenocarcinomas NOS and 2 cystadenocarcinomas with MASC features and without ETV6 rearrangement, one low-grade cribriform cystadenocarcinoma ( LGCCC), 9 AciCCs, 10 MECs, 10 adenoid cystic carcinomas (Ade CCs), 5 polymorphous low-grade adenocarcinomas ( PLGAs), and 10 pleomorphic adenomas ( PAs)] was analyzed by immunohistochemistry with mammaglobin, GCDFP-15, and p63 antibodies. Results Positivity for mammaglobin was observed in all MASCs, cystadenocarcinomas, LGCCC, and PLGAs, in some adenocarcinomas NOS, PAs, and MECs, rarely in Aci CCs and never in Ade CCs. Positivity for GCDFP-15 was observed in most of the tumor types except in Ade CCs. Interestingly, cytoplasmic positivity for p63 was observed in most of MASCs and PLGAs while rarely in adenocarcinomas NOS and PAs, and never in the other tumor types. Conclusion Our study revealed the usefulness of mammaglobin and p63 cytoplasmic staining to define which tumors are worth to be screened for ETV6 rearrangement. [ABSTRACT FROM AUTHOR]

To describe a family with a hereditary ferritinopathy (HF) due to a mutation in the ferritin light chain gene ( FTL498-499InsTC mutation). Case reports of the clinical features, MRI, 18FDG PET, and pathological findings observed in this family with two patients described in more details. Postural tremor (phenotype-1) or cerebellar signs (phenotype-2) were the first neurological symptoms detected. Parkinsonian, cerebellar and pyramidal syndromes, abnormal involuntary movements, dementia were observed in both phenotypes at more advanced stages. Beside characteristics T2* hypointense signals suggestive of iron accumulation in the striatum, mesencephalon, and cerebellum, we detected more diffuse changes including cerebellar, cortical and subcortical atrophy, cortical iron deposition, and severe leukoencephalopathy. 18FDG PET showed frontal and cerebellum hypometabolism with more severe frontal defect in patients with cognitive decline. Pathological examination showed ferritin and iron deposition in the liver, kidney, muscle, skin, and in the central nervous system. Members of this family affected by HF due to the FTL498-499InsTC mutation have a specific clinical presentation with initial postural tremor or cerebellar ataxia, followed by pyramidal and extrapyramidal motor syndromes and late severe subcortical dementia. © 2009 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Cytologic pleomorphism has been described in a limited number of benign pineal tumors, namely pineocytoma (PC) and pineal parenchymal tumors (PPTs) of intermediate differentiation (PPTID). We examined the clinicopathologic features in a retrospective series of 14 cases (seven females and seven males aged from 10 to 65 years) of pleomorphic PPT. Seven cases were PC, with no mitoses and with areas of tumoral cells forming large pineocytomatous rosettes and other areas with giant cells containing hyperchromatic nuclei. The other seven were PPTID, presenting few mitoses (≤2), a Ki67 proliferation index between 3% and 7%, and predominantly composed of small neoplastic cells and scattered giant cells, sometimes multinucleated. In the 14 tumors, the proportion of pleomorphic areas was variable. Most tumoral cells showed extensive neuronal differentiation with strong expression of neuron-specific enolase, synaptophysin and neurofilaments. Some of the neoplastic cells expressed S100 protein. The follow-up period ranged from 1.2 to 13 years and only one PC and one PPTID progressed after stereotactic biopsy or incomplete resection. The lack of invasiveness and the low proliferation index of these tumors suggest a benign clinical course despite the marked pleomorphism, the latter of which can lead to upgrading. [ABSTRACT FROM AUTHOR]

We report four heterozygous dynamin 2 (DNM2) mutations in five centronuclear myopathy patients aged 1 to 15 years. They all presented with neonatal hypotonia with weak suckling. Thereafter, their phenotype progressively improved. All patients demonstrated muscle weakness prominent in the lower limbs, and most of them also presented with facial weakness, open mouth, arched palate, ptosis, and ophthalmoparesis. Electrophysiology showed only myopathic changes, and muscle biopsies showed central nuclei and type 1 fiber hypotrophy and predominance. Our results expand the phenotypic spectrum of dynamin 2-related centronuclear myopathy from the classic mild form to the more severe neonatal phenotype. Ann Neurol 2007 [ABSTRACT FROM AUTHOR]