Central Neurocytoma Treatment Modalities: A Systematic Review Assessing the Outcomes of Combined Maximal Safe Resection and Radiotherapy with Gross Total Resection

Novel insights toward diagnosis and treatment of glioneuronal and neuronal tumors in young adults

Aim: Glioneuronal and neuronal tumors are rare primary central nervous system malignancies with heterogeneous features. Due to the rarity of these malignancies diagnosis and treatment remains a clinical challenge. Methods: Here we performed a narrative review aimed to investigate the principal issues concerning the diagnosis, pathology, and clinical management of glioneuronal tumors. Results: Diagnostic criteria have been recently overturned thanks to a better characterization on a histological and molecular biology level. The study of genomic alterations occurring within these tumors has allowed us to identify potential therapeutic targets including BRAF, FGFR, and PDGFRA. Conclusion: Techniques allowing molecular sequencing DNA methylation assessment of the disease are essential diagnostic tools. Targeting agents should be included in the therapeutic armamentarium after loco-regional treatment failure.

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.

Whole-exome sequencing reveals genetic variants that may play a role in neurocytomas

OBJECTIVES

Neurocytomas (NCs) are rare intracranial tumors that can often be surgically resected. However, disease course is unpredictable in many patients and medical therapies are lacking. We have used whole exome sequencing to explore the molecular etiology for neurocytoma and assist in target identification to develop novel therapeutic interventions.

METHODS

We used whole exome sequencing (WES) to compare the molecular landscape of 21 primary & recurrent NCs to five normal cerebellar control samples. WES data was analyzed using the Qiagen Clinical Insight program, variants of interest (VOI) were interrogated using ConSurf, ScoreCons, & Ingenuity Pathway Analysis Software to predict their potential functional effects, and Copy number variations (CNVs) in the genes of interest were analyzed by Genewiz (Azenta Life Sciences).

RESULTS

Of 40 VOI involving thirty-six genes, 7 were pathogenic, 17 likely-pathogenic, and 16 of uncertain-significance. Of seven pathogenic NC associated variants, Glucosylceramidase beta 1 [GBA1 c.703T > C (p.S235P)] was mutated in 5/21 (24%), Coagulation factor VIII [F8 c.3637dupA (p.I1213fs*28)] in 4/21 (19%), Phenylalanine hydroxylase [PAH c.975C > A (p.Y325*)] in 3/21 (14%), and Fanconi anemia complementation group C [FANCC c.1162G > T (p.G388*)], Chromodomain helicase DNA binding protein 7 [CHD7 c.2839C > T (p.R947*)], Myosin VIIA [MYO7A c.940G > T (p.E314*)] and Dynein axonemal heavy chain 11 [DNAH11 c.3544C > T (p.R1182*)] in 2/21 (9.5%) NCs respectively. CNVs were noted in 85% of these latter 7 genes. Interestingly, a Carboxy-terminal domain RNA polymerase II polypeptide A small phosphatase 2 [CTDSP2 c.472G > A (p.E158K)] of uncertain significance was also found in > 70% of NC cases.

INTERPRETATION

The variants of interest we identified in the NCs regulate a variety of neurological processes including cilia motility, cell metabolism, immune responses, and DNA damage repair and provide novel insights into the molecular pathogenesis of these extremely rare tumors.

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.

Radiotherapy for rare primary brain tumors

Rare central nervous system tumors are defined by an incidence rate of less than 6 cases per 100 000 individuals a year. It comprises a large panel of entities including medulloblastoma, glioneuronal tumors, solitary fibrous tumors, rare pituitary tumors, ependymal or embryonal tumors. The management of these tumors is not clearly defined and radiotherapy indications should be discussed at a multidisciplinary board. Image-guided and intensity-modulated radiation therapy should be proposed and MRI has a fundamental place in the treatment preparation. To avoid the occurrence of side effects, proton therapy is playing an increasingly role for the treatment of these tumors.

Clinical prognostic factors for central neurocytoma and subgroup analysis of different treatment measures: A SEER database-based retrospective analysis from 2003 to 2019

Purpose

The study aimed to identify clinical prognostic factors affecting overall survival (OS) in patients with central neurocytoma (CN) and to determine independent prognostic factors in the subgroups of different treatment modalities using a retrospective analysis based on the SEER database from 2003 to 2019.

Materials and methods

Data regarding patients with CN, including basic clinical characteristics, treatment measures, and prognosis follow-up, were extracted from the SEER database. The prognostic variables for all patients were assessed using log-rank test as well as univariate and multivariate analyses based on the Cox proportional hazards model. The same statistical methods were used for analysis in different subgroups of gross total resection (GTR), subtotal resection (STR), no surgery, radiotherapy (RT), and no RT.

Results

In total, 413 patients were enrolled in this study. Tumor size, primary site surgery, and RT were independent prognostic factors in all patients with CN. In subgroup analyses, RT was not an independent prognostic factor in patients with GTR. However, sex and race were independent prognostic factors in patients with STR. Additionally, tumor size was an independent prognostic factor in patients who did not undergo surgery. Furthermore, sex and primary site were independent prognostic factors in patients who received RT. Size and primary site surgery were independent prognostic factors in patients without RT.

Conclusion

In our study, patients with small tumors or GTR or those who did not receive RT showed a better prognosis. GTR was the preferred treatment for CN. RT was not recommended for patients after GTR. Men and African American showed certain advantages after STR surgery. Tumors with a size of >4 cm were recommended for active treatment. In the RT subgroup, patients with tumors outside the ventricle or women had a poorer prognosis than those with tumors within the ventricle or men, respectively. These findings will help clinicians and patients understand the treatment and prognosis of CN visually and intuitively.

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.

EANO - EURACAN - SNO Guidelines on circumscribed astrocytic gliomas, glioneuronal, and neuronal tumors

In the new WHO 2021 Classification of CNS Tumors the chapter "Circumscribed astrocytic gliomas, glioneuronal and neuronal tumors" encompasses several different rare tumor entities, which occur more frequently in children, adolescents, and young adults. The Task Force has reviewed the evidence of diagnostic and therapeutic interventions, which is low particularly for adult patients, and draw recommendations accordingly. Tumor diagnosis, based on WHO 2021, is primarily performed using conventional histological techniques; however, a molecular workup is important for differential diagnosis, in particular, DNA methylation profiling for the definitive classification of histologically unresolved cases. Molecular factors are increasing of prognostic and predictive importance. MRI finding are non-specific, but for some tumors are characteristic and suggestive. Gross total resection, when feasible, is the most important treatment in terms of prolonging survival and achieving long-term seizure control. Conformal radiotherapy should be considered in grade 3 and incompletely resected grade 2 tumors. In recurrent tumors reoperation and radiotherapy, including stereotactic radiotherapy, can be useful. Targeted therapies may be used in selected patients: BRAF and MEK inhibitors in pilocytic astrocytomas, pleomorphic xanthoastrocytomas, and gangliogliomas when BRAF altered, and mTOR inhibitor everolimus in subependymal giant cells astrocytomas. Sequencing to identify molecular targets is advocated for diagnostic clarification and to direct potential targeted therapies.

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.

Clinical Outcome After Microsurgical Resection of Central Neurocytoma: A Single-Centre Analysis of 15 Years

Objective: This study aimed to explore the immediate postoperative and long-term outcomes of central neurocytoma (CN) based on 15 years of experience in our institution.

Methods: This single-institution study collected data of 43 patients with CN who underwent surgery between 2005 and 2020. We reviewed data of clinical, immediate postoperative outcome, and long-term outcome of patients. More specifically, we divided complications into neurological and regional complications groups.

Results: Among the 43 patients with CN who underwent surgery, the transcortical (72.1%) or transcallosal (25.6%) approach was used. There were 18 patients (41.9%) who complained about postoperative neurological complications, including motor weakness (25.6%), memory deficit (18.6%), aphasia (7.0%), and seizure (4.7%). In addition, 18 patients suffered postoperative regional complications such as hydrocephalus (2.3%), hematoma (34.9%), infection (4.7%), and subcutaneous hydrops (2.3%). Only one-quarter of patients had suffered permanent surgical complications. The majority of patients recovered from the deficit and could turn back to normal life. There were no significant differences in the clinical outcomes between transcortical and transcallosal approaches. At a median follow-up of 61.8 months, the 5-year overall survival and progression-free survival were 87.0 and 74.0%, respectively. A multivariate Cox model analysis showed that the extent of resection was not related to progression-free survival. However, the extent of resection was significantly associated with overall survival, and gross total resection decreased the risk of death.

Conclusions: Patients with CN show favorable outcomes after surgery. The transcortical and transcallosal approaches have similar postoperative complication rates and long-term follow-up outcomes. In terms of long-term prognosis, maximal safety resection should be the first choice of CN.

Impact of Adjuvant Radiotherapy in Patients with Central Neurocytoma: A Multicentric International Analysis

Simple Summary

Central neurocytoma is a rare tumor accounting for <0.5% of all intracranial tumors. We analyzed 33 patients treated with surgical resection with or without radiotherapy from ten closely cooperating institutions in Germany, Egypt, and Jordan. Patients who received radiotherapy had longer progression-free survival with an acceptable toxicity profile.

Abstract

Background: Central neurocytoma (CN) is a rare tumor accounting for <0.5% of all intracranial tumors. Surgery ± radiotherapy is the mainstay treatment. This international multicentric study aims to evaluate the outcomes of CNs patients after multimodal therapies and identify predictive factors. Patients and methods: We retrospectively identified 33 patients with CN treated between 2005 and 2019. Treatment characteristics and outcomes were assessed. Results: All patients with CN underwent surgical resection. Radiotherapy was delivered in 19 patients. The median radiation dose was 54 Gy (range, 50–60 Gy). The median follow-up time was 56 months. The 5-year OS and 5-year PFS were 90% and 76%, respectively. Patients who received radiotherapy had a significantly longer PFS than patients without RT (p = 0.004) and a trend towards longer OS. In addition, complete response after treatments was associated with longer PFS (p = 0.07). Conclusions: Using RT seems to be associated with longer survival rates with an acceptable toxicity profile.

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.

Lateral ventricular liponeurocytoma: Review of literature and case illustration

BACKGROUND

Liponeurocytoma is an uncommon tumor of the central nervous system. It is very rare for this tumor to originate within the lateral ventricle. In the context of the rarity of this tumor entity, this review article aims to summarize the clinical, radiological, and pathological features of lateral ventricular liponeurocytoma to facilitate its diagnosis and management.

METHODS

Here, we conduct a systematic literature review using the Pubmed, Scopus, and Cochrane Library database for all cases of lateral ventricular liponeurocytoma. A case illustration complements this review.

RESULTS

The described cases from 1997 onward include 14 cases that have been published in full papers in the English literature. Six additional cases are reported in short English abstracts in full non-English papers, and one case was described in a central neurocytoma report. There is a definite male predominance of 70% (14 male) and a mean age of 37 years (range 24-62). Heterogenous enhancement and signals in magnetic resonant images (MRI) are the radiological characteristics. In all reported cases, the presence of lipocytes and fat vacuoles is considered the paramount histopathological feature. Total surgical resection was achieved in 80% (12 out of 15) of the cases. Only two cases (including ours) received radiation therapy. Recurrence was seen in two patients during follow-up that was treated by radiation therapy in one and surgery in the other. The proliferation index is mostly below 5% in all cases, with the Ki-67 range between<1% to 10%.

CONCLUSIONS

Lateral ventricular liponeurocytoma has been treated effectively by surgical resection in a limited number of cases. The decision for radiation therapy is based on a high proliferation index and tumor recurrence.

Clinico-radiological characteristics, histo-pathological features and long-term survival outcomes in central neurocytoma: A single-institutional audit

Central neurocytoma is a rare benign brain tumor that typically arises from the subependymal lining of the lateral ventricles in young adults and is generally associated with excellent survival following neurosurgical excision alone. This is a retrospective clinical audit of biopsy-proven neurocytoma registered between 2004 and 2019 at a single institution in India. All time-to event outcomes were analyzed using Kaplan-Meier method and compared with the log-rank test. Any p-value <0.05 was considered statistically significant. A total of 66 patients with neurocytoma were included in the descriptive analysis. Median age of study cohort was 31 years with equitable gender ratio. Majority (83%) of tumors were intraventricular, lateral ventricle being the commonest location. Following maximal safe resection, patients were generally kept on close clinico-radiological surveillance. Most patients (80%) had typical World Health Organization (WHO) grade II neurocytoma with remaining 20% showing histological atypia and/or high-grade features. Outcome analysis was restricted to 35 patients with relevant treatment details and adequate follow-up information. Six patients experienced recurrent/progressive disease with 2 documented deaths. At a median follow up of 52 months, 5-year Kaplan-Meier estimates of progression-free survival and overall survival were 93.3% and 96.8% respectively. Three patients developed delayed recurrence (>5-years after initial diagnosis) underscoring the importance of long-term follow-up. Atypical/high-grade histology was associated with inferior survival that may stand to benefit with upfront adjuvant radiotherapy. This represents the largest single-institution series of central neurocytoma and demonstrates excellent outcomes with adequate surgical resection alone, reserving radiotherapy for large residual tumor, recurrent disease, and/or atypical high-grade histology.

Delving Inside the Enigmatic Central Neurocytoma: Electronic Hospital Database Retrieval

Introduction:

Central neurocytomas (CNCs) appear as a rare benign intraventricular lesions involving <0.5% of primary brain tumors. There are no consensus guidelines for the optimal management strategy, so that this entity still enigmatic.

Aim:

This review aims to highpoint the entity of central neurocytoma in patients managed by our department and the unique surgical considerations, to review the epidemiology and demographics in patients treated in our institution.

Methods:

This retrospective analysis was conducted by reviewing tall patients managed at King Hussein Medical Center (KHMC) and their medical records. Patient reports were retrieved from the electronic hospital database for a 14-year period (2004 _ 2018). The review was permitted by the Royal Medical Services Institutional ethics committee. As this study was a retrospective chart review, the requirement for consent was waived.

Results:

Study revealed 33- patients who had Central neurocytoma as the underlying cause for admission. Of the final population 42.4% of the patients were males. Mean age at diagnosis was 29.48±9.78 years. Two cases were extra-ventricular, to cases were anaplastc. Only one patient developed recurrence.

Conclusion:

We have one the large series of Central neurocytomas in literature. They are benign and total resection is feasible. New adjuvant therapies are flourishing. Supplementary studies are required clarify the cardinal factors responsible for its pathogenesis; diagnosis; and to consolidate management approaches protocol.