BCOR::CREBBP fusion in malignant neuroepithelial tumor of CNS expands the spectrum of methylation class CNS tumor with BCOR/BCOR(L1)-fusion.

Methylation class "CNS tumor with BCOR/BCOR(L1)-fusion" was recently defined based on methylation profiling and tSNE analysis of a series of 21 neuroepithelial tumors with predominant presence of a BCOR fusion and/or characteristic CNV breakpoints at chromosome 22q12.31 and chromosome Xp11.4. Clear diagnostic criteria are still missing for this tumor type, specially that BCOR/BCOR(L1)-fusion is not a consistent finding in these tumors despite being frequent and that none of the Heidelberger classifier versions is able to clearly identify these cases, in particular tumors with alternative fusions other than those involving BCOR, BCORL1, EP300 and CREBBP. In this study, we introduce a BCOR::CREBBP fusion in an adult patient with a right temporomediobasal tumor, for the first time in association with methylation class "CNS tumor with BCOR/BCOR(L1)-fusion" in addition to 35 cases of CNS neuroepithelial tumors with molecular and histopathological characteristics compatible with "CNS tumor with BCOR/BCOR(L1)-fusion" based on a comprehensive literature review and data mining in the repository of 23 published studies on neuroepithelial brain Tumors including 7207 samples of 6761 patients. Based on our index case and the 35 cases found in the literature, we suggest the archetypical histological and molecular features of "CNS tumor with BCOR/BCOR(L1)-fusion". We also present four adult diffuse glioma cases including GBM, IDH-Wildtype and Astrocytoma, IDH-Mutant with CREBBP fusions and describe the necessity of complementary molecular analysis in "CNS tumor with BCOR/BCOR(L1)-alterations for securing a final diagnosis.

Valor pronóstico de la perfusión cerebral por RM en el estudio inicial de los gliomas de alto grado / Prognostic value of brain perfusion by MRI in the initial study of high grade gliomas

Objetivos: Valorar si la perfusión tumoral en el estudio diagnóstico inicial de RM es un marcador pronóstico para la supervivencia en pacientes diagnosticados de gliomas de alto grado. Analizar los factores de riesgo que influyen en la mortalidad por gliomas de alto grado para poder cuantificar la supervivencia global esperada del paciente. Pacientes y métodos: Se seleccionaron las RM de todos los pacientes diagnosticados de glioma de alto grado en un hospital de tercer nivel entre los años 2017 y 2019. Se recogieron variables clínicas y tumorales. Se usó el análisis de supervivencia para determinar la asociación entre la perfusión tumoral y el tiempo de supervivencia. Se estudió la relación entre las variables recogidas y la supervivencia mediante el estadístico de Wald, cuantificando esta relación mediante la regresión de Cox. Por último, se analizó el tipo de relación existente entre la perfusión tumoral y la supervivencia a través del estudio de regresión lineal. Estos análisis estadísticos se realizaron con el software SPSS v.17. Resultados: Se incluyeron 38 pacientes (media de edad 61,1años). La supervivencia media global fue de 20,6meses. Se observó asociación entre la perfusión tumoral en la RM diagnóstica y la supervivencia global, mostrando el grupo con valores intratumorales de volumen sanguíneo cerebral relativo (rVSC) >3,0 una disminución significativa en el tiempo medio de supervivencia respecto al grupo con valores <3,0 (14,6meses vs 22,8meses, p=0,046). También han demostrado influir significativamente en la supervivencia media variables como la escala de Karfnosky y el tiempo de recidiva desde la intervención. Conclusiones: Se ha evidenciado que la perfusión tumoral por RM tiene valor pronóstico en el estudio inicial de los gliomas de alto grado.(AU)

Objectives: To evaluate if the tumour perfusion at the initial MRI scan is a marker of prognosis for survival in patients diagnosed with high grade gliomas (HGG). To analyse the risk factors which influence on the mortality from HGG to quantify the overall survival to be expected in patients. Patients and methods: The patients diagnosed with HGG through a MRI scan in a third-level hospital between 2017 and 2019 were selected. Clinical and tumour variables were collected. The survival analysis was used to determine the association between the tumour perfusion and the survival time. The relation between the collected variables and the survival period was assessed through Wald's statistical method, measuring the relationship via Cox's regression model. Finally, the type of relationship that exists between the tumour perfusion and the survival was analysed through the lineal regression method.Those statistical analysis were carried out using the software SPSS v.17. Results: Thirty-eight patients were included (average age: 61.1years old). The general average survival period was 20.6months. A relationship between the tumour perfusion at the MRI scan and the overall survival has been identified, in detail, a group with intratumor values of relative cerebral blood volume (rCBV) >3.0 has shown a significant decline in the average survival period with regard to the average survival period of the group with values <3.0 (14.6months vs. 22.8months, P=.046). It has also been proved that variables like Karnofsky's scale and the response time since the intervention significantly influence on the survival period. Conclusions: It has become evident that the tumour perfusion via MRI scan has a prognostic value in the initial analysis of HGG. The average survival period of patients with rCBV less than or equal to 3.0 is significantly higher than those patients whose values are higher, which allows to be more precise with the prognosis of each patient.(AU)

[Supratentorial neuroepithelial tumor with PLAGL1 gene fusion - a new type of morphologically variable pediatric brain neoplasm defined by a distinct DNA methylation class. A case report and literature review]. / Supratentorial'naya neiroepitelial'naya opukhol' so sliyaniem gena PLAGL1 u detei ­ novyi tip opukholi mozga s raznoobraznoi morfologicheskoi kartinoi i otlichitel'nym metilyatsionnym profilem(sluchai iz praktiki i obzor literatury).

BACKGROUND: Methylation analysis has become a powerful diagnostic tool in modern neurooncology. This technique is valuable to diagnose new brain tumor types. OBJECTIVE: To describe the MRI and histological pattern of neuroepithelial tumor with PLAGL1 gene fusion. MATERIAL AND METHODS: We present a 6-year-old patient with small right frontal intraaxial tumor causing drug resistant epilepsy. Despite indolent preoperative clinical course and MRI features suggesting glioneuronal tumor, histological evaluation revealed characteristics of high-grade glioma, ependymoma and neuroblastoma. RESULTS: Methylation analysis of tumor DNA confirmed a new type of a recently discovered neoplasm - neuroepithelial tumor with PLAGL1 fusion (NET PLAGL1). PCR confirmed fusion of PLAGL1 and EWSR1 genes. No seizures were observed throughout the follow-up period. There was no tumor relapse a year after surgery. CONCLUSION: Methylation analysis in neurooncology is essential for unclear tumor morphology or divergence between histological and clinical data. In our case, this technique confirmed benign nature of tumor, and we preferred follow-up without unnecessary adjuvant treatment.

Expanding the Imaging Spectrum of Polymorphous Low-Grade Neuroepithelial Tumor of the Young in Children.

Polymorphous low-grade neuroepithelial tumors of the young (PLNTY) are rare brain tumors first described in 2017 and recently included in the 2021 5th World Health Organization Classification of Tumors of the Central Nervous System. They typically affect children and young adults. Few pediatric cases have been reported in the literature. The most common imaging features described, include location within the temporal lobe, involvement of the cortical/subcortical region, coarse calcifications, and well-defined margins with solid and cystic morphology, with slight-or-no enhancement. However, there is limited information on imaging features in children. We present the imaging spectrum of neuroimaging features in a series of pediatric patients with a histologically and molecularly proved PLNTY diagnosis. Coarse calcifications are uncommon in children compared with the adult literature, and they may develop with time. The transmantle-like sign can be observed, and adjacent cortical dysplasia may be seen. Seizure recurrence may occur despite gross total resection of the tumor.

Polymorphous low-grade neuroepithelial tumour of young (PLNTY): the new kid on the block.

INTRODUCTION: Polymorphous low grade neuroepithelial tumor of the young (PLNTY) is a newly described epileptogenic tumor first reported by Jason. T. Huse et al. in 2016. Only a very few cases have been reported so far and has been recently incorporated in the World Health Organization (WHO) Central Nervous System Classification of tumours, 5th edition, 2021. Here we report a rare case of PLNTY which closely resembles DNET (Dysembryoplastic neuroepithelial tumor) with plenty of interesting findings which would otherwise go unnoticed resulting in a nonspecific or misclassified diagnosis. CASE REPORT: A 12 year old boy presented to the Neurosurgery OPD with seizures for the past five years and was given multiple antiepileptics for the same. Magnetic resonance imaging (MRI) showed a well-defined lobulated cortical mass with T1 hypo intensity and T2 hyperintensity in the left temporal lobe measuring 2.1 × 2 × 1.3 cm suggesting a DNET. Left temporal craniotomy and excision of the lesion was done. Frozen section showed features of a low grade glial neoplasm. Routine sections demonstrated polymorphous findings including oligodendroglia like features, neuronal nuclear pleomorphism, spindled astroglial elements, perivascular rosettes, calcification, and vascular mineralization. By immunohistochemistry (IHC), the tumor cells were diffusely positive for GFAP and CD34.Ki67 labelling index was low. A final diagnosis of PLNTY was made based on the above findings. The child has been epilepsy free since the past one-month post-surgery and is on follow up. DISCUSSION/CONCLUSION: PLNTY is a newly discovered distinct pediatric low grade glial neoplasm which was earlier grouped into nonspecific forms of DNET. It is characterized morphologically and molecularly by the presence of oligodendroglial component, CD34 expression, BRAFV600E mutation and alterations in the MAP kinase pathway. They are known to behave in a low-grade fashion amenable to control by excision with occasional cases of recurrence reported. It is important to recognize and report similar tumors to determine the long-term risk of recurrence and create a more complete understanding on their radiology and molecular genetics.

Transcallosal and endoscopic hybrid approach to a rare entity of pediatric intraventricular tumors-cribriform neuroepithelial tumor: a case report and literature review.

PURPOSE: Cribriform neuroepithelial tumor (CRINET) is a provisional category of intraventricular tumors, sharing similarities with AT/RTs, and there is a lack of data about its pathology, prognosis, and surgical approaches in the literature. We have been challenged to describe the surgical approach to a rare case of CRINET and describe the intraoperative features since none has been described before. Surgical resection and chemotherapy hold a great importance of favorable prognosis. METHODS: Twenty-month-old male with intraventricular tumor underwent transcallosal intraventricular tumor resection and endoscopic intraventricular second look stages. The tumor was initially considered choroid plexus carcinoma and histopathological results pointed CRINET. The patient also received Ommaya reservoir for intrathecal chemotherapy employment. The patient's preoperative and postoperative MRI scans and tumor's pathological features are described with a brief history of the disease in the literature. RESULTS: Lack of SMARCB1 gene immunoreactivity and presence of cribriform non-rhabdoid trabecular neuroepithelial cells led to the CRINET diagnosis. The surgical technique helped us to approach directly into the third ventricle and perform total resection and intraventricular lavage. The patient recovered without any perioperative complications and is consulted pediatric oncology for further treatment planning. CONCLUSION: With our limited knowledge on the matter, our presentation may provide an inside to the course and progress of the CRINET as a very rare tumor and may help to set a basis for future investigations focused on its clinical and pathological features. Long courses of follow-up periods are required for establishing treatment modules and assessing the responses to surgical resection techniques and chemotherapy protocols.

Radiological and surgical aspects of polymorphous low-grade neuroepithelial tumor of the young (PLNTY).

BACKGROUND: Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a low-grade epilepsy-associated tumor recently introduced in WHO 2021 classification. Since it has been recognized as an independent nosological entity, PLNTY has been mainly studied from a genetic and molecular perspective, not recognizing unique characteristic clinical and radiological features. METHODS: A systematic literature research has been conducted aiming to identify all relevant studies about the radiological, clinical and surgical features of PLNTY. We described a representative case of a 45-year-old man treated with awake-surgery with confirmed diagnosis of PLNTY, reporting the radiological and surgical characteristics through imaging and intra-operative video. We performed a statistical meta-analysis attempting to assess the presence of relationships between surgical and radiologic tumor characteristics and clinical outcome and type of surgery. RESULTS: A total of 16 studies were included in the systematic review. The final cohort was composed of 51 patients. Extent of resection (EOR) and outcome are not significantly associated with the different genetic profiling (p = 1), the presence of cystic intralesional component, calcification (p = 0.85), contrast-enhancing and lesion boundaries (p = 0.82). No significant correlation there is between EOR and remission or better control of epilepsy-related symptoms (p = 0.38). The contrast enhancement in the tumor is significantly associated with recurrence or poor control of epileptic symptoms (p = 0.07). CONCLUSIONS: In PLNTYs, contrast enhancement seems to impact prognosis, recurrence, and seizure control much more than radiological features, genetic features and type of resection of the tumor.

Radiology-Pathology and Surgical Correlation in Astroblastoma.

Astroblastoma is a rare astrocytic glial neoplasm that affects mainly young girls, peaking between 10 and 30 years of age, with low- and high-grade manifestations. Imaging characteristics are well-described, but histopathologic and, more recently, molecular analysis is fundamental to establish the diagnosis, now based on MN1 alterations. We describe a case with typical imaging and histologic features of an MN1-altered astroblastoma.

Imaging in a new pediatric brain tumor-a supratentorial neuroepithelial tumor with PLAGL1 fusion.

Molecular diagnostics have dramatically influenced the classification of tumor groups in the 2021 WHO CNS tumor classification. Studies focusing on molecular diagnostics continue to identify new tumors. Soon after the summary of the new classification was published, "Supratentorial Neuroepithelial Tumor with PLAGL1 Fusion" was described as a distinct entity. Although this new entity is defined pathologically, its imaging features are undefined. This case report discusses the imaging findings and possible differential diagnosis of the new tumor.

A rare central nervous system tumor of childhood with spongiform appearance on brain magnetic resonance imaging; primary diffuse leptomeningeal oligodendrogliomatosis / Un raro tumor del sistema nervioso central de la infancia con apariencia espongiforme en la resonancia magnética cerebral; oligodendrogliomatosis leptomeníngea difusa primaria

Primary diffuse leptomeningeal oligodendrogliomatosis is a rare fatal tumor of childhood. Symptoms usually occur when the tumor causes hydrocephalus. Brain magnetic resonance imaging (MRI) may be nearly normal in the early stages of the disease, while hydrocephalus and multiple leptomeningeal cysts with spongiform appearance may appear later on. One may consider the diagnosis when radiologic findings become apparent with multiple leptomeningeal cysts. However, failure to recognize the imaging findings due to the rarity of the disease may delay the diagnosis. Here, we report a 3.5-year-old girl who presented with ataxia and vomiting and had a diagnosis of primary diffuse leptomeningeal glioneuronal tumor with remarkable brain MRI findings as diffuse multiple tiny cystic lesions on the brain and spinal cord. She benefited from radiotherapy and temozolomide treatment with remission of brain MRI findings. Increasing the number of reported cases will enable the elucidation of the disease's pathogenesis and the development of treatment protocol (AU)

La oligodendrogliomatosis leptomeníngea difusa primaria es un tumor fatal infrecuente de la infancia. Los síntomas generalmente ocurren cuando este causa hidrocefalia. La resonancia magnética (RM) cerebral puede ser casi normal en las primeras etapas de la enfermedad, mientras que la hidrocefalia y múltiples quistes leptomeníngeos con apariencia espongiforme pueden aparecer más adelante. Se puede considerar el diagnóstico cuando los hallazgos radiológicos se hacen visibles con la aparición de varios quistes leptomeníngeos. Sin embargo, el hecho de no reconocer estas evidencias en las imágenes debido a la rareza de la enfermedad puede retrasar el diagnóstico. Aquí, presentamos el caso de una niña de 3,5 años con ataxia y vómitos que tenía un diagnóstico de tumor glioneuronal leptomeníngeo difuso primario con muchas lesiones quísticas diminutas difusas en el cerebro y en la médula espinal observadas en la RM cerebral. La paciente se benefició del tratamiento con radioterapia y temozolomida con remisión de los hallazgos de la RM cerebral. El aumento del número de casos notificados permitirá dilucidar la patogénesis de la enfermedad y desarrollar protocolos de tratamiento (AU)

Uncommon Glioneuronal Tumors: A Radiologic and Pathologic Synopsis.

Glioneuronal tumors are characterized exclusively by neurocytic elements (neuronal tumors) or a combination of neuronal and glial features (mixed neuronal-glial tumors). Most of these tumors occur in young patients and are related to epilepsy. While ganglioglioma, dysembryoplastic neuroepithelial tumor, and desmoplastic infantile tumor are common glioneuronal tumors, anaplastic ganglioglioma, papillary glioneuronal tumor, rosette-forming glioneuronal tumor, gangliocytoma, and central neurocytoma are less frequent. Advances in immunohistochemical and molecular diagnostics have improved the characterization of these tumors and favored the description of variants and new subtypes, some not yet classified by the World Health Organization. Not infrequently, the histologic findings of biopsies of glioneuronal tumors simulate low-grade glial neoplasms; however, some imaging findings favor the correct diagnosis, making neuroimaging essential for proper management. Therefore, the aim of this review was to present key imaging, histopathology, immunohistochemistry, and molecular findings of glioneuronal tumors and their variants.

Clinicoradiological and histopathological characteristics and treatment outcomes of cerebral astroblastoma in children: a single-institution experience.

OBJECTIVE: Astroblastoma (AB) is a rare glial tumor. The optimal treatment and prognosis of this tumor remain unclear. The authors retrospectively analyzed the clinical characteristics, neuroimaging findings, histopathological results, and treatment outcomes of 7 patients with AB. METHODS: The study comprised 7 patients with pathologically proven AB who were surgically treated at Samsung Medical Center from November 1994 to January 2019. Clinicoradiological, histopathological, and surgical records were reviewed. RESULTS: The patients included 5 girls (71.4%) and 2 boys (28.6%), with a median age of 13 years. All patients showed contrast enhancement on preoperative MRI: 5 ABs (71.4%) showed a concomitant solid and cystic appearance, and 2 (28.6%) demonstrated a solid appearance. ABs in 6 patients (85.7%) showed a well-circumscribed, characteristic "bubbly" appearance on T2-weighted MRI. Gross-total resection (GTR) was achieved in all cases (100%). Six patients (85.7%) were diagnosed with high-grade AB and 1 (14.3%) with low-grade AB. Six (85.7%) of the 7 patients received adjuvant treatment after resection, including 5 (83.3%) with AB who received chemotherapy and radiotherapy and 1 (16.7%) who received proton therapy alone. The median clinical follow-up duration was 96 months (range 48-189 months). Two patients experienced recurrence, and all patients in this series were alive at the last follow-up. CONCLUSIONS: In this study, the clinicoradiological and histopathological features of AB were described. Based on the authors' limited experience with 7 cases, resection with the goal of GTR is currently the mainstream treatment for AB, and adjuvant radiation treatment should be considered after surgery.

Spinal astroblastoma: a rare tumour in an unusual location.

Astroblastomas are central nervous system tumours with unknown cell of origin and clinical behaviour. These tumours occur most commonly in cerebral hemispheres with spinal astroblastomas being very rare. We report a case of spinal astroblastoma which harboured MN1 alteration.

Neuroradiological features of the polymorphous low-grade neuroepithelial tumor of the young: five new cases with a systematic review of the literature.

PURPOSE: Polymorphous low-grade neuroepithelial tumors of the young (PLNTY) is a newly recognized brain tumor with genetic abnormalities frequently involving either BRAF or FGFR2/FGFR3. There are few publications available about the neuroradiological features of PLNTY. In this systematic review, we assessed the demographic, clinical, and neuroradiological features of PLNTY. METHODS: Literature data were extracted from database searches in MEDLINE and SCOPUS databases up to June 10, 2021. Studies reporting on pathologically proven PLNTY with neuroradiological findings were included. After reviewing 103 abstracts, 9 articles encompassing 19 cases met the inclusion criteria. We also added five patients from our hospital. The correlations between the presence of "transmantle-like sign" and the following three factors: duration of seizures; tumor size; and pathologically proven cortical dysplasia, were examined. RESULTS: The median patient age was 15.5 years (range, 5-57 years), and 15/24 (62.5%) were female. All tumors were localized supratentorialy. The main radiological features included cortical or subcortical masses (95.8%) in the temporal lobe (66.7%), calcification (83.3%), well-defined margins (72.7%), solid and cystic components (66.6%), and T2-weighted imaging (T2WI) hyperintensity (50.0%). The duration of seizure was significantly longer (positive vs. negative (median [range]), 24 months [6 - 96 months] vs. 5 months [1 - 12 months], p = 0.042), and the presence of the cortical dysplasia was significantly more frequent (3/8 vs 0/16, p = 0.042) in the patients with transmantle-like sign. CONCLUSION: PLNTY typically represents a calcified, well-defined mass in the supratentorial cortical or subcortical regions. The radiological findings defined here could facilitate the diagnosis of PLNTY.