Pediatric atypical extraventricular neurocytoma: Clinical features and survival outcomes.

BACKGROUND: Extraventricular neurocytoma (EVN) in children is an extremely rare encountered tumor. Little information is available about the treatment and prognosis of this rare disease in children. This study was undertaken to elucidate the clinical-radiological characteristics and treatment outcomes of pediatric patients with atypical EVN. METHODS: A retrospective review of patients' demographic features, treatment modalities, and outcomes in our institution from January 2011 to December 2019 was conducted. RESULTS: Seven consecutive children harboring atypical EVN in our center were included, with a male predominance (n = 5, 71.4%) and a mean age of 11.8 ± 4.9 years (range: 2-18 years). The lesions mainly involved the frontal (n = 4, 57.1%) and temporal lobes (n = 4, 57.1%). Gross total resection (GTR) was achieved in 6 patients (85.7%), and subtotal resection (STR) was achieved in the remaining patient (14.3%). All lesions demonstrated a high Ki-67 index (≧5%) and atypical features pathologically. Five patients (71.4%) received radiotherapy and/or chemotherapy after surgery. During follow-up, 5 patients (71.4%) experienced lesion progression, and 2 (14.3%) of them died. The median progression-free survival was 48 months. CONCLUSIONS: The prognosis of pediatric patients with atypical EVN was dismal after aggressive treatment. Most tumors progressed, and this progression was positively correlated with the Ki-67 index. Surgical excision is the main treatment modality for atypical EVN, and radiation/chemotherapy should also be introduced after surgery.

Atypical extraventricular neurocytoma: A case report.

Atypical extraventricular neurocytoma (EVN) is a rare condition characterized by diffuse tumor cell hyperplasia, increased neovascularization, increased necrosis, and aggressive characteristics. A case of a 25-year old man who presented with atypical EVN in his left parietal - occipital flaps is reported. Magnetic resonance imaging (MRI) revealed a well-defined globular mass with heterogeneous signals in the left parietal lobe, and mild perilesional edema. After left parietal craniotomy and tumor excision, pathologic examination of the resected tissue revealed that the lesion was localized mainly in the white matter and imbued with tumor cells possessing round hyperchromatic nuclei with perinuclear halos and increased microvascular proliferation. The patient underwent radiotherapy at 21st postoperative day. Over the past 26 months, the patient has been regularly followed up, and so far no neurologic deficits have been observed. The latest MRI showed that the tumor bed was stable with slight peritumoral edema. The results of clinical, histopathological and immunohistochemical examinations indicate that atypical EVN is a rare neoplasm with unique radiographic and pathologic characteristics. It possesses more aggressive properties than typical EVN.

The epidemiology of central and extraventricular neurocytoma in the United States between 2006 and 2014.

INTRODUCTION: Central neurocytoma (CN) and extraventricular neurocytoma (EVN) are rare intracranial tumors. There is a paucity of studies reporting the population-based incidence of these tumors. We used the Central Brain Tumor Registry of the United States (CBTRUS), which contains the largest aggregation of population-based data on the incidence of primary central nervous system tumors in the United States to describe these tumors. METHODS: The CBTRUS database, provided by CDC representing approximately 100% of the US population, was queried using the following search criteria: diagnosis years 2006-2014, ICD-0-3 histology codes (9506/0: central neurocytoma, benign; 9506/1: central neurocytoma, uncertain). Annual age-adjusted incidence rates are presented per 100,000 population. Incidence was estimated by age, gender, race, and ethnicity. RESULTS: The combined overall annual incidence rate of CN and EVN was 0.032 [0.030-0.034]. The incidence rates were 0.022 [0.021-0.024] and 0.009 [0.008-0.010] for CN and EVN, respectively. The most frequently documented locations for EVN were frontal lobe and cerebellum, followed by temporal lobe. Peak incidence was found in the 20-34 years range for both CN and EVN. The incidence rate was slightly lower in males compared to females for CN and identical for EVN. The overall incidence rate of CN and EVN combined was lower in Blacks 0.026 [0.021-0.032] and Hispanic Whites 0.020 [0.016-0.025] compared to Non-Hispanic Whites 0.035 [0.033-0.038]. CONCLUSION: CN and EVN are rare tumors with a peak incidence in the 20-34 years age group. This study represents the largest population-based epidemiological study on CN and EVN in the US.

Malignant progression of an extraventricular neurocytoma arising from the VIIIth cranial nerve: A case report and literature review.

A rare case of extraventricular neurocytoma (EVN) arising from the VIIIth cranial nerve in a 34-year-old woman is reported. The patient had a 20-year history of hearing loss and facial palsy. Computed tomography showed a 3-cm enhancing lesion in the left cerebellopontine angle (CPA). At operation, the tumor was seen to originate from the cochlear and vestibular nerves. The tumor was subtotally resected. Histologically, the tumor consisted of uniform cells with oval to round nuclei and scant cytoplasm. Immunohistochemically, the tumor cells were positive for synaptophysin, but negative for glial fibrillary acid protein and S-100 protein. The Ki-67 labeling index was 0%. Twelve years after the operation, magnetic resonance imaging (MRI) showed tumor recurrence at the left CPA. The tumor was subtotally resected, and radiation therapy was given. Histologically, the tumor consisted of round cells with mild atypia and one mitosis/20 high-power fields (HPF). Immunohistochemically, tumor cells showed the same findings as the first operation sample, except for the Ki-67 labeling index (3%). Twelve years after the second operation, MRI showed a second tumor recurrence at the left CPA and surroundings of the brain stem. The tumor was subtotally resected. Histologically, the tumor consisted of anaplastic short spindle cells and five mitoses/10 HPF. The immunohistochemical findings were almost the same as the earlier operation samples. However, the Ki-67 labeling index was 20%. In addition, tumor cells from the third specimen were more strongly and more diffusely positive for GAB1 (growth factor receptor-bound protein 2-associated binding protein 1) compared to those of the earlier specimens. Electron microscopy showed the presence of numerous cell processes with a dense core and clear vesicles and microtubules. GAB1 immunostaining also indicated that malignant progression might be associated with the sonic hedgehog signaling pathways. To the best of our knowledge, this is the first report of an EVN arising from the VIIIth cranial nerve with malignant progression.

FGFR1:TACC1 fusion is a frequent event in molecularly defined extraventricular neurocytoma.

Extraventricular neurocytoma (EVN) is a rare primary brain tumor occurring in brain parenchyma outside the ventricular system. Histopathological characteristics resemble those of central neurocytoma but exhibit a wider morphologic spectrum. Accurate diagnosis of these histologically heterogeneous tumors is often challenging because of the overlapping morphological features and the lack of defining molecular markers. Here, we explored the molecular landscape of 40 tumors diagnosed histologically as EVN by investigating copy number profiles and DNA methylation array data. DNA methylation profiles were compared with those of relevant differential diagnoses of EVN and with a broader spectrum of diverse brain tumor entities. Based on this, our tumor cohort segregated into different groups. While a large fraction (n = 22) formed a separate epigenetic group clearly distinct from established DNA methylation profiles of other entities, a subset (n = 14) of histologically diagnosed EVN grouped with clusters of other defined entities. Three cases formed a small group close to but separated from the epigenetically distinct EVN cases, and one sample clustered with non-neoplastic brain tissue. Four additional samples originally diagnosed otherwise were found to molecularly resemble EVN. Thus, our results highlight a distinct DNA methylation pattern for the majority of tumors diagnosed as EVN, but also indicate that approximately one third of morphological diagnoses of EVN epigenetically correspond to other brain tumor entities. Copy number analysis and confirmation through RNA sequencing revealed FGFR1-TACC1 fusion as a distinctive, recurrent feature within the EVN methylation group (60%), in addition to a small number of other FGFR rearrangements (13%). In conclusion, our data demonstrate a specific epigenetic signature of EVN suitable for characterization of these tumors as a molecularly distinct entity, and reveal a high frequency of potentially druggable FGFR pathway activation in this tumor group.

A clinicopathologic study of extraventricular neurocytoma.

In 2007, extraventricular neurocytoma was classified as a separate entity among glioneuronal tumors. However, extraventricular neurocytoma is not fully understood and may be misdiagnosed. Here, we describe the clinical and pathological features, prognoses, and treatments of 13 extraventricular neurocytoma cases, and compare their immunophenotypes with those of oligodendroglioma, diffuse astrocytoma, and ependymoma. Six typical and 7 atypical cases comprised the 13 extraventricular neurocytoma cases. Histological features included oligodendroglioma-like perinuclear halo, neuropil-like matrix, ganglion or ganglioid cells, perivascular pseudorosettes, vessel hyalinization, calcifications, and myxoid degeneration. Atypical histological features included increased mitotic figures, focal necrosis, endothelial cell proliferation, and/or a Ki-67 index of >2%. All lesions expressed synaptophysin and microtubule-associated protein-2, which distinguished them from other similar tumors. Two patients with atypical extraventricular neurocytoma had tumor recurrence, one of whom had cerebrospinal fluid dissemination, suggesting that atypical histological features might represent adverse prognostic factors. In conclusion, the present study identified morphological and immunohistochemical features that would aid the differential diagnosis of extraventricular neurocytoma. In addition, radiotherapy with subtotal resection could be considered an effective treatment for extraventricular neurocytoma, but because a pediatric patient died of intracranial hemorrhage during radiotherapy, radiotherapy-related side effects should be considered, especially when treating children. Additional cases with long-term follow-up are needed to develop optimal management protocols for extraventricular neurocytoma.

Mesial temporal extraventricular neurocytoma: a rare cause of refractory complex partial seizure.

AIM: Mesial temporal extraventricular neurocytoma (mtEVN) is a rare cause of refractory complex focal seizures. The characteristics of this clinical entity are discussed in this article. METHODS: We report two cases of mtEVN and review the related literature, with particular emphasis on radiological characteristics, clinical features, and operative techniques. RESULTS: After successful surgery, our two cases of mtEVN achieved excellent outcome. Including the cases presented here, a total of three cases of mtEVNs and 11 of neocortical temporal extraventricular neurocytoma (ntEVNs) are reported in the literature. mtEVNs are distinct from ntEVNs with regards to demographics, aetiology, radiological features, and operative techniques. CONCLUSION: mtEVNs and ntEVNs exhibit distinguishing features. Under electrocorticographic monitoring, tailored resection of the neocortical epileptogenic focus, as well as the entire tumour and mesial temporal structures, can yield excellent outcome and satisfactory seizure control.

Survival outcomes of intracranial extraventricular neurocytomas: a systematic review and individual patient data meta-analysis.

OBJECTIVE: The rarity of intracranial extraventricular neurocytomas (EVNs) has precluded accurate definition of its surgical characteristics to date. The authors present the first survival analysis of this unique entity that aims to clarify tumor characteristics, surgical outcomes, and efficacy of postoperative adjuvant therapy. METHODS: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Searches of the MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Database of Systematic Reviews databases were performed from inception to date. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Prognostic variables were age, sex, tumor consistency, extent of resection, and receipt of postoperative adjuvant therapy. Survival data were analyzed using Kaplan-Meier survival curves and the log-rank test to compare dichotomized cohorts. Multivariate Cox regression models were constructed, interrogated with Schoenfeld residuals, and subsequently utilized to identify independent prognostic factors. Risk of bias was assessed with the Mayo Clinic instrument. RESULTS: Five hundred fourteen articles were initially retrieved, which was distilled to 10 included articles consisting of 101 cases of intracranial EVNs. The 5-year OS rate was 90.4% (95% CI 81.8%-99.8%) and the PFS rate was 48.6% (95% CI 34.46%-68.8%). The median PFS was 60 months. Patients younger than 50 years of age experienced superior OS (p = 0.03) and PFS (p < 0.01). Gross-total resection (GTR) was superior to subtotal resection (STR) in reducing mortality (p < 0.01). Adjuvant therapy following either STR or GTR did not significantly improve survival. CONCLUSIONS: Intracranial EVNs are rare tumors that portend a poorer prognosis than central neurocytomas, despite both being WHO grade 2 tumors. Complete surgical extirpation is the cornerstone of management. There is no clearly established role for adjuvant postoperative therapy, but each case should be managed on an individual basis.

Extraventricular Neurocytoma of the Posterior Fossa: A Case Report Written by ChatGPT.

ChatGPT (Chat Generative Pre-trained Transformer) is the latest artificial intelligence (AI) tool that has taken the internet by storm. A large language model-based AI tool, ChatGPT is used to generate natural prose-like answers learning from a large database of text. A lot is being written and spoken about the future of academic writing using this tool.We attempt to generate a short case report of a brain tumour labelled extraventriuclar neurocytoma (EVN) which is a rare tumour of the central nervous system. When posed with a set of questions on this uncommon topic, ChatGPT did well with relevant but not very specific answers. Validation of the information is an issue like with most machine learning solutions. This case report is an attempt to summarise EVN and its management. Q: Summarise extraventricular neurocytoma. ChatGPT: EVN is a rare and benign tumor that typically occurs in the brain. It often causes no symptoms, but as it grows, it can cause headaches, seizures, and changes in vision or balance. Surgery is usually curative, but there is a lack of studies to know the best treatment options. The prognosis is generally good with high rates of long-term survival and low rates of recurrence. Text italicised in the article is generated by ChatGPT.

Intraventricular central neurocytoma molecularly defined as extraventricular neurocytoma: a case representing the discrepancy between clinicopathological and molecular classifications.

Central neurocytoma (CN) is classically defined by its intraventricular location, neuronal/neurocytic differentiation, and histological resemblance to oligodendroglioma. Extraventricular neurocytoma (EVN) shares similar histological features with CN, while it distributes any site without contact with the ventricular system. CN and EVN have distinct methylation landscapes, and EVN has a signature fusion gene, FGFR1-TACC1. These characteristics distinguish between CN and EVN. A 30-year-old female underwent craniotomy and resection of a left intraventricular tumor at our institution. The histopathology demonstrated the classical findings of CN. Adjuvant irradiation with 60 Gy followed. No recurrence has been recorded for 25 years postoperatively. RNA sequencing revealed FGFR1-TACC1 fusion and methylation profile was discrepant with CN but compatible with EVN. We experienced a case of anatomically and histologically proven CN in the lateral ventricle. However, the FGFR1-TACC1 fusion gene and methylation profiling suggested the molecular diagnosis of EVN. The representative case was an "intraventricular" neurocytoma displaying molecular features of an "extraventricular" neurocytoma. Clinicopathological and molecular definitions have collided in our case and raised questions about the current definition of CN and EVN.

Extraventricular neurocytoma at the sellar region: Report of 8 cases and literature review.

BACKGROUND: Extraventricular neurocytoma at the sellar region (EVNSR) is an exceedingly rare tumor. Given the paucity of specificity and its peculiar nature, our study aimed to characterize the clinical, imaging, and pathological features, including treatment and clinical outcomes of this tumor. METHOD: Eight patients with pathologically confirmed EVNSR at Beijing Tiantan Hospital from 2012 to 2020 were retrospectively analyzed. Additionally, 7 cases from the prior detailed literature were also retrieved. FINDINGS: Among the 8 patients from Beijing Tiantan Hospital, 2 males and 6 females with an average age of 45.3 (range, 8-61). Vision impairment and headache were the most common complaints at presentation. Preoperative diagnoses were pituitary adenoma (n = 6), meningioma (n = 1), and oligodendroglioma (n = 1). Treatment included subtotal tumor resection (n = 3), partial resection (n = 5), adjuvant therapy covered radiotherapy (n = 2), and gamma knife surgery (n = 3). The clinical outcomes of these 8 cases were stable (n = 5), survival after progression (n = 1), and death after recurrence (n = 2). CONCLUSIONS: EVNSRs are extremely rare tumors, and most have benign prognoses after appropriate treatment. Due to the unique location, total removal of the tumor is challenging; And adjuvant radiation therapy for eligible patients is recommended. Regular imaging review is also advised. Future studies with more patients are needed to elucidate the biological nature of EVNSRs.

A Clinicopathological and Molecular Analysis of Sellar/Suprasellar Neurocytoma Mimicking Pituitary Adenoma.

Objective: To investigate the clinicopathological characteristics, molecular genetic characteristics and prognosis of extraventricular neurocytoma located in the sellar/suprasellar region. Methods: Seven archived tumor samples derived from 4 patients with neurocytoma in the sellar/suprasellar region were collected from the First Affiliated Hospital of Fujian Medical University and the Affiliated Hospital of Qingdao University and retrospectively analyzed for clinical manifestations, imaging features, and histopathological features. Neuronal and pituitary biomarkers and molecular features were detected in these tumor tissues by immunohistochemistry and FISH or Sanger sequencing. The related literature was reviewed. Results: Three patients were female, while 1 was male, with an average age of 35.5 years (range: 27 to 45 years). The initial manifestations were mainly headache and blurred vision in both eyes. The first MRI examination showed marginally enhancing masses in the intrasellar or intra- to suprasellar region. The diagnosis of pituitary adenomas was based on imaging features. The levels of pituitary hormones were normal. Histologically, the tumor cells were arranged in a sheet-like, monotonous architecture and were uniform in size and shape with round to oval, exquisite and hyperchromatic nuclei, which densely packed close to one another and were separated only by a delicate neuropil background. There was no evident mitosis, necrosis or microvascular proliferation. The three cases of recurrent tumors were highly cellular and showed increased mitotic activity. Immunohistochemically, the tumor cells were positive for syn, CR, CgA, and vasopressin and were focally positive for NeuN, TTF-1, NF, CK8, vimentin, and S100 proteins. Other markers, including IDH1, BRAF VE1, Olig-2, and EMA, were negative. Pituitary transcription factors and anterior pituitary hormones were negative. Molecular genetic testing showed that the tumor cells lacked IDH gene mutations, LOH of 1p/19q, MYCN amplification, and EGFR alteration. With a median follow-up of 74.5 months (range 23 to 137 months), 3 patients relapsed at 11, 50, and 118 months after the initial surgery. Conclusion: The morphological features and immunophenotypes of neurocytoma in the sellar/suprasellar region are similar to those of classic central neurocytoma. The prognosis is relatively good. Gross-subtotal resection and atypical subtype may be related to tumor recurrence.

A rare diagnosis of an extraventricular neurocytoma.

BACKGROUND: Extraventricular neurocytoma (EVN) is an extremely rare neoplasm of the central nervous system. As reported, it arises in a variety of locations, but mainly within the cerebral hemispheres. Despite its histological similarity with central neurocytoma (CN), EVN occurs outside the ventricular system and, in 2007, was recognized by the World Health Organization as a separate entity. CASE DESCRIPTION: A 39-year-old man, with a ventriculoperitoneal shunt inserted for communicating hydrocephalus, was admitted at our Unit of Neurosurgery with a 1-month history of gait disturbance, postural instability, speech disorders, and occasional incontinence. Computed tomography scan and magnetic resonance imaging showed a mixed-density neoplasm in the left frontotemporal area, with anterior cerebral falx shift, and perilesional edema. The patient underwent surgical procedure; microsurgical excision of the lesion was performed through left pterional approach. Histopathological and immunohistochemical examination revealed monomorphic round cells of the neuronal lineage, with a percentage of Ki-67 positive nuclei <5% and no evidence of mitosis or necrotic areas. According to radiologic features, this pattern was compatible with the diagnosis of EVN. Patient had a favorable recovery and he is still in follow-up. CONCLUSION: Because of their rarity, clinical, radiologic, and histopathological characteristics of EVNs are not yet well defined, as well as the optimal therapeutic management. Whereas EVNs are rarely described in literature, we aimed to share and discuss our experience along with a review of the published literature.

Cerebellar Neurocytoma with Excellent Response to Radiotherapy.

BACKGROUND: Extraventricular neurocytoma (EVN) is a rare neurocytoma occurring in the brain parenchyma outside the ventricular system that shares similar biological behaviors and histopathologic characteristics with central neurocytoma. Reports of EVN localized in the brainstem and cerebellum are relatively uncommon. In addition, few cases with radiotherapy as the only treatment have been reported and their outcomes were unclear. CASE DESCRIPTION: We report a case of pathologically confirmed EVN of the brainstem and cerebellum in a 43-year-old male who presented with unprovoked nausea and dizziness. The patient received radiotherapy only and showed a favorable outcome during the 2-year follow-up period. CONCLUSIONS: These results suggest that patients with EVN who are treated with radiotherapy without surgery may have a favorable prognosis.

Comprehensive analysis of diverse low-grade neuroepithelial tumors with FGFR1 alterations reveals a distinct molecular signature of rosette-forming glioneuronal tumor.

The FGFR1 gene encoding fibroblast growth factor receptor 1 has emerged as a frequently altered oncogene in the pathogenesis of multiple low-grade neuroepithelial tumor (LGNET) subtypes including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumor (DNT), rosette-forming glioneuronal tumor (RGNT), and extraventricular neurocytoma (EVN). These activating FGFR1 alterations in LGNET can include tandem duplication of the exons encoding the intracellular tyrosine kinase domain, in-frame gene fusions most often with TACC1 as the partner, or hotspot missense mutations within the tyrosine kinase domain (either at p.N546 or p.K656). However, the specificity of these different FGFR1 events for the various LGNET subtypes and accompanying genetic alterations are not well defined. Here we performed comprehensive genomic and epigenomic characterization on a diverse cohort of 30 LGNET with FGFR1 alterations. We identified that RGNT harbors a distinct epigenetic signature compared to other LGNET with FGFR1 alterations, and is uniquely characterized by FGFR1 kinase domain hotspot missense mutations in combination with either PIK3CA or PIK3R1 mutation, often with accompanying NF1 or PTPN11 mutation. In contrast, EVN harbors its own distinct epigenetic signature and is characterized by FGFR1-TACC1 fusion as the solitary pathogenic alteration. Additionally, DNT and pilocytic astrocytoma are characterized by either kinase domain tandem duplication or hotspot missense mutations, occasionally with accompanying NF1 or PTPN11 mutation, but lacking the accompanying PIK3CA or PIK3R1 mutation that characterizes RGNT. The glial component of LGNET with FGFR1 alterations typically has a predominantly oligodendroglial morphology, and many of the pilocytic astrocytomas with FGFR1 alterations lack the biphasic pattern, piloid processes, and Rosenthal fibers that characterize pilocytic astrocytomas with BRAF mutation or fusion. Together, this analysis improves the classification and histopathologic stratification of LGNET with FGFR1 alterations.

Extraventricular neurocytoma with ganglioid differentiation of the sellar and parasellar regions in an elderly patient: A case report.

BACKGROUND: Extraventricular neurocytoma (EVN) is a rare variant of central neurocytoma which arises outside of the ventricular system. Diffuse ganglioid differentiation is a characteristic seen in a subset of these tumors which has an uncertain prognostic significance. Typically, EVN presents in children and young adults. Given the rarity of this tumor, the natural history and response to treatments remain unclear. CASE DESCRIPTION: We present a case of EVN with diffuse ganglioid differentiation in a 70-year-old male which arose in the midline parasellar region and extended into the third ventricle. This is the oldest such patient reported. Despite prior reports that extremes of age are associated with more aggressive behavior, the tumor in this case did not exhibit such an aggressive course. CONCLUSION: In this report, we review the natural history and clinical course of this patient and summarize the literature regarding this rare pathological entity. Our patient responded well to therapy despite older age, ganglioid differentiation, and higher mitotic index.

Complete resection of hypervascularised extraventricular neurocytoma after preoperative embolisation. / Resección completa de neurocitoma extraventricular hipervascularizado tras embolización preoperatoria.

A 13-year-old female arrived at the Emergency Department with a two-week history of headache, and bilateral papilloedema on examination. The initial study with CT and MRI showed a large multicystic left frontal mass with calcification surrounded by peripheral oedema, subacute intralesional bleeding and association of multiple large vessels. She was initially operated on in another centre where a subacute haematoma was found, evacuating to multiple vessels and arteriolised veins. Despite the earlier neuroimaging findings, arteriovenous malformation (AVM) was suspected, so she was referred to our centre for further treatment. We performed angiography, MR angiography and MRI with advanced sequences, diagnosing a highly vascularised intra-axial tumour which was embolised. The patient was then definitively operated on, with the resulting finding of extraventricular neurocytoma (EVN). EVN are extremely rare lesions, not previously described in the literature as hypervascularised lesions, which in our case required prior angiography and embolisation for proper diagnosis and adequate management.

Mesial temporal extraventricular neurocytoma (mtEVN): A case report and literature review.

AIM: We describe a case of mesial temporal extraventricular neurocytoma (mtEVN) in a 23-year-old male presenting with drug-resistant seizures and review the literature on this rare tumor. METHODS: A PubMed search was queried using the MeSH term "neurocytoma" and key search terms "extraventricular", "temporal", and "epilepsy". Titles and abstracts were screened for temporal neurocytomas. References were reviewed to identify further studies. RESULTS: Twenty case reports were selected comparing the presentation, radiological, histopathological, and surgical outcomes of neocortex temporal EVNs (ntEVN) and mtEVNs. CONCLUSION: Gross total resection of mtEVNs under intraoperative electrocorticography monitoring typically affords an excellent prognosis and successful seizure control.

Intramedullary central neurocytoma of the thoracic spinal cord: A case report and literature review.

Central neurocytomas (CNs) are rare benign tumors located in the central nervous system with a good prognosis. These tumors are predominantly located in the lateral ventricle near the foramen of Monro or in the third ventricle. Similar tumors that are located outside the ventricle are also called extraventricular neurocytomas, and have an even lower morbidity. Until now, several tumors have been identified in the thalamus, cerebellum, pons, medulla oblongata and spinal cord. In total, 24 cases of neurocytomas located in the spinal cord have been reported in English journals. The present study reported a patient with an intramedullary central neurocytoma of the thoracic spinal cord, diagnosed from clinical features, imaging findings, pathology and immunohistochemistry. The present case report also outlined the prognosis of the patient and reviewed the literature currently available on CNs located in the spinal cord.

Congenital Extra-Ventricular (Ganglio)Neurocytoma of the Brain Stem: A Case Report.

Extraventricular neurocytoma (EVN) is an extremely rare tumor of neuroglial origin with a tendency toward ganglionic or glial differentiation. In the 2016 World Health Organization Classification, EVN was classified as a grade II tumor and described as a neoplasm with good outcome. However, the presence of cellular atypia is an important unfavorable prognostic factor. Here, we describe the first case of a patient with a congenital EVN localized in the brainstem. After a sub-total resection, his disease rapidly progressed despite several chemotherapies, including molecular targeting approaches. He died 13 months after diagnosis. In conclusion, we report an atypical case of EVN presenting an extremely aggressive behavior, despite the absence of cellular atypia. The brainstem origin and the age of the patient may have represented two important prognostic factors for our patient.