Update on the diagnosis, pathogenesis, and treatment strategies for central neurocytoma

Long-term outcomes of central neurocytoma - an institutional experience

INTRODUCTION

Central Neurocytoma (CN) is a rare, WHO grade 2 brain tumor that predominantly affects young adults. Gross total resection (GTR) is often curative for CNs, but the optimal treatment paradigm including incorporation of RT, following subtotal resection (STR) and for scarcer pediatric cases has yet to be established.

METHODS

Patients between 2001 and 2021 with a pathologic diagnosis of CN were reviewed. Demographic, treatment, and tumor characteristics were recorded. Recurrence free survival (RFS) and overall survival (OS) were calculated according to the Kaplan Meier-method. Post-RT tumor volumetric regression analysis was performed.

RESULTS

Seventeen adults (≥ 18 years old) and 5 children (< 18 years old) met the criteria for data analysis (n = 22). With a median follow-up of 6.9 years, there was no tumor-related mortality. Patients who received STR and/or had atypical tumors (using a cut-off of Ki-67 > 4%) experienced decreased RFS compared to those who received GTR and/or were without atypical tumors. RFS at 5 years for typical CNs was 67% compared to 22% for atypical CNs. Every pediatric tumor was atypical and 3/5 recurred within 5 years. Salvage RT following tumor recurrence led to no further recurrences within the timeframe of continued follow-up; volumetric analysis for 3 recurrent tumors revealed an approximately 80% reduction in tumor size.

CONCLUSION

We provide encouraging evidence that CNs treated with GTR or with RT after tumor recurrence demonstrate good long-term tumor control.

Molecular and clinical characterization of atypical central neurocytomas: implications for diagnosis and treatment strategies

OBJECTIVES

This study aimed to investigate the histological and molecular characteristics of atypical central neurocytomas (CNs) and evaluate their clinical treatment outcomes, with the aim of identifying reliable biomarkers for differentiation and optimal treatment strategies.

METHODS

We conducted a retrospective study including 61 patients diagnosed with CNs. Clinical data, neuroimaging, and pathological findings were analyzed. RNA sequencing was performed on tumor tissues to identify differentially expressed genes.

RESULTS

Histological atypia and the Ki-67 index showed no significant impact on progression-free survival (PFS) or overall survival (OS). RNA sequencing identified significant genetic alterations in pathways such as neuroactive ligand-receptor interaction, cAMP, MAPK, and Ras signaling. Differently expressed genes included AMOTL1, PIK3R3, TGFBR1, SMO, COL4A6, MGP, SOX4, IGF2, SLIT1, and CKS2. The five-year OS rate (p = 0.015) and PFS rate (p = 2.00 × 10-6) were significantly higher in the complete resection (CR) group compared to the incomplete resection (IR) group. Postoperative radiotherapy did not affect OS or PFS in the CR group. The five-year PFS rate (p = 3.80 × 10-5) was significantly longer in patients in the CR group who did not receive radiotherapy compared to those in the IR group who did receive radiotherapy. The extent of surgical resection and operative approaches were found to be irrelevant to perioperative complications and dysfunctions at the last follow-up.

CONCLUSION

CR is crucial for a better prognosis in patients with atypical CNs. Additional radiotherapy after CR offers little benefit. Histological atypia and the Ki-67 index are not effective in distinguishing between atypical and typical CNs. Identified genetic alterations provide insights into the aggressive behavior of atypical CNs, suggesting potential therapeutic targets and underscoring the need for further research to optimize treatment strategies.

Imaging of supratentorial intraventricular masses in children: a pictorial review-part 2

PURPOSE

This article is the second in a two-part series aimed at exploring the spectrum of supratentorial intraventricular masses in children. In particular, this part delves into masses originating from cells of the ventricular lining, those within the septum pellucidum, and brain parenchyma cells extending into the ventricles. The aim of this series is to offer a comprehensive understanding of these supratentorial intraventricular masses, encompassing their primary clinical findings and histological definitions.

METHODS

We conducted a review and analysis of relevant epidemiological data, the current genetics/molecular classifications as per the fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (WHO CNS5), and imaging findings. Each supratentorial intraventricular mass was individually evaluated, with a detailed discussion on its clinical and histological features.

RESULTS

This article covers a range of supratentorial intraventricular masses observed in children. These include colloid cysts, subependymal giant cell astrocytomas, ependymomas, gangliogliomas, myxoid glioneuronal tumors, central neurocytomas, high-grade gliomas, pilocytic astrocytomas, cavernous malformations, and other embryonal tumors. Each mass type is characterized both clinically and histologically, offering an in-depth review of their individual imaging characteristics.

CONCLUSION

The WHO CNS5 introduces notable changes, emphasizing the vital importance of molecular diagnostics in classifying pediatric central nervous system tumors. These foundational shifts have significant potential to impact management strategies and, as a result, the outcomes of intraventricular masses in children.

Gamma Knife radiosurgery for central neurocytoma: a quantitative systematic review and metanalysis

Central neurocytomas (CN) are rare tumors within the central nervous system. Originating from the septum pellucidum and subependymal cells, they are typically found in the third and lateral ventricles. For this reason, they may lead to hydrocephalus and increased intracranial pressure. CNs are generally benign lesions that exhibit locally aggressive behavior and a high recurrence rate. Complete surgical resection is the preferred treatment; however, due to their anatomical location, this is often not feasible. Based on these findings, Gamma Knife radiosurgery (GKRS) has been introduced for managing both residual and recurrent tumors and as an initial therapy in selected cases. This study aimed to systematically review the available knowledge regarding GKRS for CN. A systematic investigation of the scientific literature was undertaken through an exhaustive search across prominent databases, including PubMed, Web of Science, and Google Scholar, by employing precise MeSH terms such as "Central neurocytoma," "Radiosurgery," "Gamma Knife," and "Stereotactic Radiosurgery." A comprehensive quantitative systematic review and meta-analysis were meticulously conducted, focusing on cases of CN treated with GKRS for a thorough evaluation of outcomes and efficacy. Seventeen articles, including 289 patients, met the inclusion criteria. Random effects meta-analysis estimates for disease control and local tumor control were 90% (95% CI 87-93%; I2 = 0%, p < 0.74) and 94% (95% CI 92-97%; I2 = 0%, p < 0.98), respectively. When considering only studies with at least 5 years of follow-up, progression-free survival was 89% (95% CI 85-94%; I2 = 0.03%, p < 0.74). The mean clinical control rate was 96%. This systematic review and meta-analysis confirmed the safety and efficacy of GKRS in managing CN.

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.

Episodic Headache, Periorbital Pain, and Multifocal Paresthesias as Presenting Symptoms of Central Neurocytoma: A Case Report

Central neurocytoma (CN) is a rare intraventricular tumor. The common presenting symptoms of CN are headache, vomiting, and visual disturbance, which results from increased intracranial pressure. This report presents a case of CN with unusual clinical presentations. A 25-year-old female with CN presented with a one-day history of unilateral headache, ipsilateral periorbital pain, multifocal paresthesias, and vomiting. Magnetic resonance images showed an intraventricular mass with a soap-bubble appearance and numerous cystic areas typical for CN, causing obstructive hydrocephalus and a midline shift. After one night of rest, her headache, periorbital pain, and paresthesias disappeared. It is possible that the tumor could be mobile with regard to the patient's head position, causing occasional obstruction of the foramen of Monro. Due to the tumor size, which was larger than 4 centimeters, the surgical approach with either gross tumor resection or subtotal resection plus adjuvant radiotherapy should be carefully considered.

Radiotherapy Protocol of Central Neurocytoma for Resource-limited Settings in the Absence of Official Guidelines: A Case Report and Review of the Literature

BACKGROUND: Central neurocytoma (CN) is one of the rarest brain tumors which can cause considerable threats to the patient. Studies and trials regarding its treatment are scarce, and no official guidelines are dedicated to this disease. The main principle of treatment generally consists of surgery and radiotherapy. The choice of radiotherapy is divided into conventional fractionated radiotherapy and stereotactic radiosurgery (SRS). However, access to SRS in developing countries such as Indonesia is still limited. AIM: We report a case delineating the timeline and process of treatment in CN with a review of the literature. METHODS: We report the case of a 29-year-old woman with a solid inhomogeneous mass (AP 5.63 × CC 5.36 × LL 5.16 cm) in the right ventricle, attached to the septum pellucidum, as displayed on the magnetic resonance imaging (MRI). The patient had been vomiting for the past three weeks and presented with bidirectional horizontal nystagmus. RESULTS: Cognitive evaluation with Montreal Cognitive Assessment (MoCA-Ina) demonstrated a mild cognitive impairment. Biopsy was performed, and pathology analysis revealed some cells with fibrillary background and some with a honeycomb-like appearance. The immunohistochemistry staining showed positive results with synaptophysin and neuronal nuclear protein. According to the WHO classification of the central nervous system tumors, the profile favored CN Grade II. Subtotal resection (STR) was performed to reduce the tumor mass, which was measured with MRI 2-month post-surgery (AP 4.09 × CC 3.01 × LL 4.13 cm) and then followed by an external radiation program. Using intensity modulated radiation therapy (IMRT), a total dose of 54 Gy was given in 27 fractions, with the average planning target volume of 54.3 Gy. There was a minuscule reduction in tumor mass as seen in post-radiotherapy MRI (AP 4.00 × CC 3.86 × LL 3.63 cm). After the last session and at the 18-month follow-up, the patient did not have any complaints or abnormalities during clinical assessment. Reevaluation using MoCA-Ina showed an improved cognitive function. CONCLUSIONS: In line with recent evidence, we demonstrated that STR followed by IMRT with the dosage of 54 Gy in 27 fractions was a feasible treatment strategy for CN that resulted in cognitive improvement, with no side effects.

Central Neurocytoma with Hemorrhagic Presentation Case Report and Review of the Literature

Central neurocytoma (CN) is slow-growing rare intraventricular tumor that represents 0.25-0.5% of all intracranial tumors in adults. Typically, it is seen in young adults, yet with surgical resection, it has excellent prognosis. Due to CN rarity and its feature similarities with other common tumors, misdiagnosis can be an issue. With no pathognomonic clinical features of CN, a proper diagnosis can be achieved by radiological imaging, magnetic resonance spectroscopy, histopathology assessment, and immunohistochemistry. Therefore, this is a case report of a 17-year-old male who presented with right lateral ventricular CN with intraventricular hemorrhage. Subtotal tumor resection was carried out via right transcortical approach. Subtle improvement for the patient condition was noted.

Less common intraparenchymal tumors

The chapter outlines the management of a great variety of rare intraparenchymal tumors. For some like medulloblastomas or ependymomas, GKNS has little to offer. For others like neurocytomas, primary central nervous system lymphomas, and papillary pineal tumors the current findings look most hopeful. For choroid plexus papillomas there is currently not enough information to define the role of GKNS in their treatment. Pineal region tumors are a complex and varied group of neoplasms. Their complexity, variety and ethnic variability means that defining the role of GKNS will require continuing research before a consensus about management can be reached.

The last decade's experience of management of central neurocytomas: Treatment strategies and new options

Background:

The purpose of the presented work is to evaluate the last decade’s experience in surgical management of central neurocytoma (CN) and elucidate on the treatment strategies and new options.

Methods:

The current series consists of the remaining 125 patients (70 females and 55 males) operated on during the past decade from 2008 to 2018. Most tumors were resected through transcortical (n = 76, 61%), or transcallosal (n = 40, 32%) approaches. In 5 (4%) patients with predominantly posterior location of the tumor, non-dominant superior parietal lobule approach was utilized. Both approaches (transcortical + transcallosal) were used in 4 (3%) of cases. Seven consecutive patients with large CN underwent prophylactic intraventricular stenting to prevent hydrocephalus.

Results:

Gross total resection was achieved in 45 patients (36%), subtotal resection (STR) in 40 (32%) cases. After surgery, 63 (50%) patients had neurocognitive problems, including disorientation, attention deficit, global amnesia, short-term memory deficits, and perceptual motor and social cognition problems. A total of 26 patients (21%) had postoperative hemorrhage in the resection bed. Obstructive hydrocephalus was noted in 25 (20%) patients. The entrapment of the occipital and/or temporal horns was observed in seven cases. None of the seven patients with prophylactic intraventricular stents required shunting.

Conclusion:

Although high rates of gross total or STR can be expected, the mortality and morbidity remain significant even in the modern neurosurgical era. Prophylactic intraventricular stenting in patients with large posteriorly located tumors with hydrocephalus may prevent ventricular entrapment and shunting. The main risk factors for recurrence are presence of residual disease and Ki-67 index over 5%. Recurrent symptomatic tumors should be treated surgically, whereas asymptomatic progression can be managed with stereotactic radiosurgery. Both treatment modalities are associated with low risk of complications and high tumor control rates.

Large lateral intraventricular tumors - Outcome of radical surgery

This is a retrospective analysis of 145 cases of lateral intraventricular tumors that were larger than 4 cm in their maximum dimension. The aim of surgery was radical tumor resection. During the period January 2000 to December 2019, 145 cases of lateral intraventricular tumors were treated by surgery by an interhemispheric approach. There were 101 males and 44 females. The ages of the patients ranged from 2 months to 77 years (average 29 years). Histological examination of tumors identified 73 central neurocytomas, 20 choroid plexus papillomas, 23 subependymal giant cell astrocytomas (SEGA), 5 ependymomas, 21 gliomas, 2 primitive neuroectodermal tumors (PNET/embryonal tumors) and 1 atypical teratoid rhabdoid tumor (ATRT). Nineteen patients had mild to severe hemiparesis in the immediate post-operative period. Eight patients died in the postoperative period. At a follow up of 1 year 137 patients were leading active and symptom free lives. Twenty seven patients received adjuvant radiation treatment. At a follow-up of more than 3 years, 8 additional patients died of their disease. Tumor recurrence or re-growth was observed in 13 patients and 2 patients needed reoperation. Surgery on large lateral intraventricular tumors can be associated with significant postoperative morbidity and mortality. Majority of tumors in this location are relatively 'low-grade' malignant tumors and when successfully treated, the long term outcome can be gratifying.

Differential Diagnosis of Central Neurocytoma: Two Cases

Central neurocytoma are rare primary brain tumors of the young and middle-aged adult, typically located in the lateral ventricles. Diagnosis has historically been difficult due to histomorphologic similarities to oligodendroglioma and ependymal tumors and remains a challenge even today. We present two cases of intraventricular central neurocytoma in which careful consideration of the clinical and radiological findings led to reevaluation of the preliminary histological interpretation, highlighting the importance of a meticulous differential diagnosis.

Atypical Central Neurocytoma: An Investigation of Prognostic Factors

OBJECTIVE

Central neurocytoma is a rare nervous tissue benign neoplasm. A subset of central neurocytoma has unfamiliar aggressive tendency: so-called atypical central neurocytoma (ACN). This retrospective study aims to analyze the prognostic factors and the impact of various therapy tools on atypical central neurocytoma.

METHODS

Twenty-two patients diagnosed with ACN between January 2009 and March 2018 were included. Data collected included the patient's age, gender, tumor location, presenting symptoms, and treatment received. Patients were followed up to detect recurrence and to assess survival.

RESULTS

Median overall survival was 57 months, with a 5-year survival of 35%. Better survival was observed for patients <35 years old (66 vs. 47 months; P = 0.061) and patients with gross total resection over subtotal resection or biopsy (76, 45, and 22 months, respectively; P < 0.0001). Patients with a tumor located in the posterior half of the lateral ventricle had better survival, with no statistical significance (P = 0.053). Multivariate analysis showed prognostic significance with the extent of resection (P = 0.000). Progression-free survival ranged from 6 to 82 months, with a median value of 38 months and showed a significant relation with subtotal resection compared with biopsy (P = 0.006). Recurrence was less in patients who received radiotherapy and was statistically significant (P = 0.007).

CONCLUSIONS

Long-term survival is possible for patients with atypical central neurocytomas treated with surgery and postoperative radiation. Multivariate analysis confirmed that gross total resection was an independent prognostic factor for survival. Adjuvant radiotherapy reduces tumor recurrence, especially after incomplete surgery.

Individual Treatment Decisions for Central Neurocytoma

Objective: Central neurocytomas (CNs) are rare, and this has resulted in a paucity of information and a lack of clarity regarding their optimal management. This study aimed to explore individual treatment strategies for CNs and the benefits of these strategies for patients.

Methods: This single-center study retrospectively analyzed data from 67 patients with CNs who underwent surgery. Based on the extent of resection, patients were divided into complete and incomplete resection groups. The patients were followed, and overall survival (OS) and progression-free survival (PFS) were determined.

Results: Of 55 patients (82.1%) who underwent complete resections, 24 received radiotherapy (24/55, 43.6%). Of 12 patients who underwent incomplete resections, 9 (9/12, 75.0%) received radiotherapy. The OS (p = 0.003) and PFS (p = 0.006) intervals were significantly longer in the complete resection group than in the incomplete resection group. Postoperative radiotherapy did not affect OS (p = 0.129) or PFS (p = 0.233) in the complete resection group. In the incomplete resection group, postoperative adjuvant radiotherapy prolonged patient survival significantly (p = 0.021). PFS was significantly longer among patients who underwent complete resection without radiotherapy than in those who underwent incomplete resection followed by radiotherapy (p = 0.034). Functional dependence on admission, which was defined as a Karnofsky Performance Status score <70, was an independent risk factor associated with long-term survival in patients with CN. Postoperative complications were not associated with the amount of tumor resected. The prognosis of patients aged ≥ 50 years was relatively poor. The atypical CN recurrence rate was relatively high (7.8%).

Conclusions: To protect function as much as possible, complete tumor resection should be the first choice of treatment for CN. After gross total resection, adjuvant radiotherapy is not acceptable. Postoperative adjuvant radiotherapy improves the prognosis of patients who have undergone incomplete tumor resections. Adjuvant radiotherapy is not recommended after complete resections of atypical CNs, and close follow-up with imaging is required. Our findings can help guide decision-making regarding the treatment of CNs and could potentially maximize the benefits of treatment for patients with CN.

Central neurocytoma originating in third ventricle with expansion into the cerebral aqueduct and fourth ventricle: Case report and review of literature

BACKGROUND

Central Neurocytomas (CNs) are rare brain tumors, making up less than 1% of all primary tumors within the CNS. They are commonly located in the lateral ventricles, and often present with visual changes and symptoms of obstructive hydrocephalus. Histopathology shows characteristics similar to ependymomas and oligodendrogliomas, however tumor cells display neuronal differentiation, and immunohistochemical stains typically for synaptophysin. Gross total resection is the most important prognostic indicator of survival.

CASE DESCRIPTION

We describe the case of a 48-year-old male with a CN originating in the third ventricle with expansion through the cerebral aqueduct into the fourth ventricle. He presented with bi-frontal headaches, imaging revealed an avidly enhancing tumor occupying the inferior third ventricle, cerebral aqueduct, with expansion into the fourth ventricle. An interhemispheric craniotomy with a transcallosal transchoroidal approach to the third ventricle was performed, this provided a trajectory that paralleled the long axis of the tumor. Postoperative imaging confirmed a near total resection with linear residual enhancement on the anterior wall of the fourth ventricle. Intensity modulated radiotherapy was performed, 7-month follow-up imaging was clean.

CONCLUSION

CNs are rare brain tumors, most commonly located within the lateral ventricles. We describe a rare case of a CN spanning from the third ventricle into the cerebral aqueduct and fourth ventricle. To our knowledge, this is only the fourth reported case of such a tumor. Surgical approach must be carefully selected, as gross total resection is the most important prognostic indicator.

Uncommon low-grade brain tumors

The 2016 World Health Organization (WHO) classification of primary central nervous system (CNS) tumors includes numerous uncommon (representing ≤1% of tumors) low-grade (grades I-II) brain neoplasms with varying clinical behaviors and outcomes. Generally, gross tumor or maximal safe resection is the primary treatment. Adjuvant treatments, though their exact role is unknown, may be considered individually based on pathological subtypes and a proper assessment of risks and benefits. Targetable mutations such as BRAF (proto-oncogene B-Raf), TRAIL (tumor necrosis factor apoptosis inducing ligand), and PDGFR (platelet derived growth factor receptor) have promising roles in future management.

Endoscopic approach and stereotactic radiosurgery for a posterior third ventricular Central Neurocytoma - case report and literature review

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Central Neurocytomas are a rare intracranial tumour, often presenting with obstructive hydrocephalus.

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Isolated lesions in the posterior third ventricle are an uncommon location for Central Neurocytomas.

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An endoscopic approach to these allows for concurrent biopsy and therapeutic cerebrospinal fluid diversion.

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Adjuvant Stereotactic Radiosurgery improves outcomes of survival and local control in subtotal resection.

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Together, this is a viable treatment for deep-seated, posterior third ventricular Central Neurocytomas.

Introduction

Central Neurocytomas (CN) are a rare intracranial tumour, most often arising in the lateral ventricles and presenting with obstructive hydrocephalus. Isolated lesions in the third ventricle are uncommon. We present the fourth reported case of posterior third ventricular CN successfully managed surgically via endoscopy, allowing for concurrent biopsy and therapeutic endoscopic third ventriculostomy (ETV). Stereotactic radiosurgery was administered for the residual lesion. A brief review of CNs and previous similar cases is also provided.

Presentation of case

A 58-year-old male presented with progressive decline in cognition and gait. Subsequent Magnetic Resonance Imaging revealed obstructive hydrocephalus secondary to a posterior third ventricular lesion. An endoscopic biopsy and concurrent cerebrospinal fluid diversion by ETV was performed. Pathological analysis was consistent with a CN with positivity to Synaptophysin. MIB-1 proliferation index was 1%. There was good clinical recovery, and the patient underwent adjuvant stereotactic radiosurgery 1.5 months post-surgery.

Discussion

Due to the rarity of CNs arising from the third ventricle, there are only three previous reports of these approached endoscopically. Such a technique allows for good visualisation of the lesion, and therapeutic ETV to relieve obstructive hydrocephalus. This case supports this approach as a valid, minimally invasive option. Additionally, this is the first case to report the MIB-1 proliferation index, contributing to future outcome evaluation of endoscopic approaches to typical (MIB-1 < = 2%) verses atypical (MIB-1 > 2%) CNs.

Conclusion

Endoscopic biopsy with concurrent ETV and adjuvant stereotactic radiosurgery is a valid treatment option for deep seated isolated small posterior third ventricular CNs.

Somatostatin Receptor Ligand Therapy-A Potential Therapy for Neurocytoma

CONTEXT

Neurocytoma (NC) is a rare, low-grade tumor of the central nervous system, with a 10-year survival rate of 90% and local control rate of 74%. However, 25% of NCs will be atypical, with an elevated Ki-67 labeling index >2%, and will exhibit a more aggressive course, with a high propensity for local recurrence and/or craniospinal dissemination. Although no standard treatment regimen exists for these atypical cases, adjuvant stereotactic or conventional radiotherapy and/or chemotherapy have been typically offered but have yielded inconsistent results.

CASE DESCRIPTION

We have described the case of a patient with a vasopressin-secreting atypical NC of the sellar and cavernous sinus region. After subtotal resection via endoscopic transsphenoidal surgery, the residual tumor showed increased fluorodeoxyglucose uptake and high somatostatin receptor (SSTR) expression on a 68Ga-DOTA-TATE positron emission tomography/CT scan. Somatostatin receptor ligand (SRL) therapy with lanreotide (120 mg every 28 days) was initiated. Four years later, the residual tumor was stable with decreased fluorodeoxyglucose tumor uptake. Immunocytochemical SSTR2 and SSTR5 expression >80% was further confirmed in a series of NC tissues.

CONCLUSIONS

To the best of our knowledge, we have described the first use of SRL therapy for an atypical NC. Our results support consideration of adjuvant SRL therapy for NC refractory to surgical removal. Our findings further raise the possibility of SSTR-directed peptide receptor radionuclide therapy as NC therapy.

Central neurocytoma: SNP array analyses, subtel FISH, and review of the literature

The central neurocytoma (CN) is a rare brain tumor with a frequency of 0.1-0.5% of all brain tumors. According to the World Health Organization classification, it is a benign grade II tumor with good prognosis. However, some CN occur as histologically "atypical" variant, combined with increasing proliferation and poor clinical outcome. Detailed genetic knowledge could be helpful to characterize a potential atypical behavior in CN. Only few publications on genetics of CN exist in the literature. Therefore, we performed cytogenetic analysis of an intraventricular neurocytoma WHO grade II in a 39-year-old male patient by use of genome-wide high-density single nucleotide polymorphism array (SNP array) and subtelomere FISH. Applying these techniques, we could detect known chromosomal aberrations and identified six not previously described chromosomal aberrations, gains of 1p36.33-p36.31, 2q37.1-q37.3, 6q27, 12p13.33-p13.31, 20q13.31-q13.33, and loss of 19p13.3-p12. Our case report contributes to the genetic knowledge about CN and to increased understanding of "typical" and "atypical" variants.

Central Neurocytoma: Rare Presentation in Fourth Ventricle and Review of Literature

Central neurocytomas are rare tumors, typically found in the third ventricle. We present the unusual case of a fourth ventricular central neurocytoma in a 70-year-old female presenting with imbalance and headaches, with an enhancing fourth ventricular mass on imaging. We examine the details of her clinical presentation, imaging characteristics, histopathologic analysis, and postoperative course. We performed a critical literature review of fourth ventricular central neurocytoma, identifying 6 previously reported cases. In contrast to our patient, the majority of these cases were in young males. The 2 females with fourth ventricular neurocytoma developed it at a much later age (mean 63.5 years) than their male counterparts (mean 22.8 years; P = 0.005). Despite being a rare cause for a fourth ventricular lesion, given the appropriate clinical context and radiographic findings, this should remain part of the differential diagnosis.

The role of proton beam therapy in central neurocytoma: A single-institution experience

PURPOSE

Central neurocytomas (CNs) are rare World Health Organization grade II tumors managed with surgery and radiation therapy. We report our experience in managing CN with proton beam therapy (PBT) when radiation therapy was used.

METHODS AND MATERIALS

We identified 61 patients with pathologically diagnosed CN treated at our institution between 1996 and 2016, of which 24 met inclusion criteria. Patient, tumor, and treatment characteristics are reported in context of progression-free survival and treatment-related adverse events.

RESULTS

Of 24 patients identified, median age at diagnosis was 21 years (range, 14-60). Median maximal tumor diameter was 4.5 cm (range, 1.4-6.8). Eighteen (75%) patients underwent upfront surgery alone. Sixteen (67%) patients received adjuvant or salvage PBT at a median dose of 54 Gy (relative biological effectiveness). Median follow-up was 56 months. Median progression-free survival (PFS) was 61 months. Eleven patients had disease progression with median time to progression of 22 months. Of the 5 patients with gross total resection, 4 experienced local recurrence and had MIB-1 >4% (range, 4.5-30). There was improved PFS with addition of PBT to definitive surgery (log-rank, P = .06); there was no disease progression to date. In patients who experienced disease recurrence/progression, MIB-1 <4% was associated with improved PFS (log-rank, P = .007). All patients tolerated PBT well with toxicities typical for cranial irradiation and with no grade 3+ toxicities.

CONCLUSION

In our cohort, CN with elevated MIB-1 index were at increased risk for disease progression. However, adjuvant radiation therapy appears to effectively prevent failure. PBT toxicities appear to be comparable to if not less than published photon experiences.

Clinical characteristics and prognostic factors of brain central neurocytoma

BACKGROUND & AIMS

This study is designed for the clinical characteristics and prognostic factors of central neurocytoma (CN).

METHODS

CN patients from 2004 to 2012 were enrolled from the Surveillance Epidemiology and End Results (SEER) data. Clinical characteristics including age, sex, race, tumor size, tumor number, surgery, and radiation therapy were summarized. Univariate and multivariate analysis were performed to explore the prognostic factors of CN.

RESULTS

CN tended to be borderline malignant and single lesion. Compared with other brain tumor (NCN), Patients with CN (CNs) were more likely to be female, young, and non-white race. Surgery was the primary treatment of CN. Univariate and Multivariate analysis indicated tumor number and surgery were both independent prognostic factors of CN (P < 0.05). Unifocal CNs had a lower mortality risk than multifocal ones (HR 0.167, 95% CI 0.052-0.537), surgery significantly reduced the death risk of CNs (HR 0.284, 95% CI 0.088-0.921).

CONCLUSIONS

CN tend to be borderline malignant, single lesion, operated on. Most CNs are female and younger. single lesion and surgery are the independent positive prognostic factors of CN.

Clinical, radiological, pathological and prognostic aspects of intraventricular oligodendroglioma: comparison with central neurocytoma

Studies comparing intraventricular oligodendroglioma (IVO) and central neurocytoma (CN) in terms of their clinical, radiological and pathological features are scarce. We, therefore, investigated the similarities and differences between these types of tumors to get a better understanding of how they may be more properly diagnosed and treated. The clinical manifestations, CT/MRI findings, pathological characteristics and clinical outcomes of 8 cases of IVOs and 12 cases of CNs were analyzed retrospectively. Both IVO and CN occurred most commonly in young adults and manifested with symptoms of increased intracranial pressure secondary to obstructive hydrocephalus. However, they were radiologically different in location (p = 0.007), diffusion-weighted imaging (p = 0.001), "scalloping" appearance (p = 0.006), flow void sign (p = 0.006) and ventricular wall invasion (p = 0.000). Histologically, significant differences in mitotic count (p = 0.008) and parenchymal infiltration (p = 0.01) were noted. Immunohistochemically, significant differences in the expression of Olig2 (p = 0.000), Syn (p = 0.01) and NeuN (p = 0.000) were observed. In addition, MIB-1 labeling index (p = 0.035) and case fatality rate (p = 0.021) of IVO were much higher than those of CN, while survival rate of IVO was much lower than that of CN (p = 0.028). IVO and CN are similar in onset age and clinical manifestations, but have different imaging and pathological features. Patients with IVOs may have a relatively poorer prognosis compared to those with CNs.

Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma

Central neurocytoma (CN) typically presents as an intraventricular mass causing obstructive hydrocephalus. The first line of treatment is surgical resection with adjuvant conventional radiotherapy. Stereotactic radiosurgery (SRS) was proposed as an alternative therapy for CN because of its lower risk profile. The objective of this systematic analysis is to assess the efficacy of SRS for CN. A systematic analysis for CN treated with SRS was conducted in PubMed. Baseline patient characteristics and outcomes data were extracted. Heterogeneity and publication bias were also assessed. Univariate and multivariate linear regressions were used to test for correlations to the primary outcome: local control (LC). The estimated cumulative rate of LC was 92.2% (95% confidence interval: 86.5-95.7%, p<0.001). Mean follow-up time was 62.4 months (range 3-149 months). Heterogeneity and publication bias were insignificant. The univariate linear regression models for both mean tumor volume and mean dose were significantly correlated with improved LC (p<0.001). Our data suggests that SRS may be an effective and safe therapy for CN. However, the rarity of CN still limits the efficacy of a quantitative analysis. Future multi-institutional, randomized trials of CN patients should be considered to further elucidate this therapy.

Central Neurocytoma: A Review of Clinical Management and Histopathologic Features

Central neurocytoma (CN) is a rare, benign brain tumor often located in the lateral ventricles. CN may cause obstructive hydrocephalus and manifest as signs of increased intracranial pressure. The goal of treatment for CN is a gross total resection (GTR), which often yields excellent prognosis with a very high rate of tumor control and survival. Adjuvant radiosurgery and radiotherapy may be considered to improve tumor control when GTR cannot be achieved. Chemotherapy is also not considered a primary treatment, but has been used as a salvage therapy. The radiological features of CN are indistinguishable from those of other brain tumors; therefore, many histological markers, such as synaptophysin, can be very useful for diagnosing CNs. Furthermore, the MIB-1 Labeling Index seems to be correlated with the prognosis of CN. We also discuss oncogenes associated with these elusive tumors. Further studies may improve our ability to accurately diagnose CNs and to design the optimal treatment regimens for patients with CNs.

Extraventricular neurocytoma in the left temporal lobe: A case report and review of the literature

Central neurocytoma (CNC) often develops in the ventricular system adjacent to the interventricular foramen and septum pellucidum. According to the World Health Organization, CNCs are classified as grade II tumors, and in recent years it has been reported that CNCs have occasionally occurred in rare areas of the central nervous system. The current study describes a rare case of CNC located in the left temporal lobe of a 49-year-old man, who had been experiencing headaches for 3 weeks. Computed tomography identified a round, well-demarcated, 3.3-cm tumor in the left temporal lobe. The patient underwent surgery and the tumor was totally resected. Histological analysis demonstrated that the resected tumor tissue contained clusters of small cells with regular nuclear morphology, and round nuclei with fine chromatin. Immunohistochemically, neuronal differentiation markers, including synaptophysin and neuronal nuclear antigen, were expressed in the tumor cells. Histopathological examination of the resected tissue confirmed a diagnosis of extraventricular neurocytoma. Magnetic resonance imaging was performed at 3 months post-surgery and demonstrated no evidence of tumor recurrence.

The typical and atypical MR imaging findings of central neurocytomas: Report on eighteen cases and review of the literature

There were few studies have documented the MRI features of typical and atypical CNCs for diagnosis and therapeutic modalities. Here, 18 histopathologically confirmed cases of intracranial CNCs (8 men and 10 women with a mean age of 28.3 years, range 10-64 years) were retrospectively analyzed. The histopathological and immunohistochemical features were also assessed. On MR imaging, the 14 typical cases of CNCs showed relatively round, lobulated tumor masses in the body of the right lateral ventricle (5 cases), left lateral ventricle (4 cases), third ventricles (2 cases), and midline (3 cases). These typical CNCs masses contained clusters of cysts of varying sizes and "soap bubble" appearance on T2WI; they showed mild to moderate heterogeneously enhancement on T1WI. The 4 atypical cases of CNCs showed as strongly contrast enhancement of the tumors with the attachment or infiltrate of the wall of the ventricle than the typical benign cases. These atypical CNCs were in the right lateral ventricle (2 cases), left lateral ventricle (1 case), and third ventricle (1 case). Microscopically, the typical CNCs were well-differentiated tumors with benign histological features. The typical and atypical CNCs were composed of uniform, small to medium-sized cells with rounded nuclei and scant cytoplasm. Immunohistochemically, the typical CNCs were strong in Syn immunopositive (14/14) and neuron-specific enolase (12/14). The atypical CNC tumor cells showed malignant behavior and more positive expression of Ki67 than the benign cases. Surgery is the first choice of treatment, and radiotherapy may be beneficial to postoperative patients.

Third Ventricular Glioblastoma Multiforme: Case Report and Literature Review

Background Glioblastoma multiforme (GBM) typically presents in the supratentorial white matter, commonly within the centrum semiovale as a ring-enhancing lesion with areas of necrosis. An atypical presentation of this lesion, both anatomically as well as radiographically, is significant and must be part of the differential for a neoplasm in this anatomical location.

Case Description We present a case of a 62-year-old woman with headaches, increasing somnolence, and cognitive decline for several weeks. Magnetic resonance imaging demonstrated mild left ventricular dilatation with a well-marginated, homogeneous, and nonhemorrhagic lesion located at the ceiling of the third ventricle within the junction of the septum pellucidum and fornix, without exhibiting the typical radiographic features of hemorrhage or necrosis. Final pathology reports confirmed the diagnosis of GBM.

Conclusion This case report describes an unusual location for the most common primary brain neoplasm. Moreover, this case identifies the origin of a GBM related to the paracentral ventricular structures infiltrating the body of the fornix and leaves of the septum pellucidum. To our knowledge this report is the first reported case of a GBM found in this anatomical location with an entirely atypical radiographic presentation.

Neurocytoma of the spinal cord

This article presents an overview of spinal neurocytomas. A rare manifestation of an uncommon tumor, extraventricular neurocytomas (EVNs) should be included in the differential for spinal intradural and intramedullary tumors. Spinal EVNs are generally benign with an indolent pathologic course but may display a variety of acute or chronic clinical behaviors, depending on their anatomic location. Only a handful of spinal EVNs have been described in the literature, often in the form of individual case reports or small case series. Discussion includes a review of the literature and an overview of the clinical, pathologic, and radiologic features of this rare tumor type, as well as the differential diagnosis, treatment options, and general prognosis.

Central neurocytoma: establishment of the disease entity

The establishment and identification of central neurocytoma as a distinct disease entity are invaluable in catalyzing investigations of neuronal differentiation in central nervous system tumors. The discovery of neuronal differentiation in neuroepithelial tumors has been extended to extraventricular tumors and potentially to various glial tumors undergoing neuronal differentiation. Understanding the disease spectrum of neuronal and mixed neuronal-glial tumors is important for deciphering the mechanism of gliomagenesis.