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

Epidemiological features of spinal intradural tumors, a single-center clinical study in Beijing, China

BACKGROUND

Spinal intradural tumors are rare and heterogeneous in histological type, aggressiveness, and symptomatology, and there is a lack of data about them. This study investigated the epidemiological features of spinal intradural tumors.

METHODS

This retrospective analysis included patients with spinal intradural tumors who underwent surgical treatment at the Myelopathy and Spondylosis Ward Beijing Jishuitan Hospital between January 2012 and December 2022.

RESULTS

This study included 1321 patients [aged 47.19 ± 14.90 years, 603 (45.65%) males] with spinal intradural tumors. The most common histological subtype was schwannoma [n = 511 (38.68%)], followed by spinal meningioma [n = 184 (13.93%)] and ependymoma [n = 101 (7.65%)]. Fifteen (1.14%) patients were diagnosed with metastatic spinal intradural tumors as a presentation of another primary cancer type. The spinal intradural tumors were mostly found in the lumbar region [n = 436 (33.01%)], followed by the thoracic vertebrae [n = 390 (29.52%)], cervical vertebrae [n = 154 (11.66%)], and thoracolumbar region [n = 111 (8.40%)]. Schwannomas mostly affected the lumbar region [n = 256 (52.64%)], spinal meningiomas in the thoracic region [n = 153 (83.15)], and ependymomas in the lumbar region [56 (55.45%)]. The de novo metastases were mostly found in the lumbar region [n = 8 (53.33%)].

CONCLUSION

According to the results of our single-center study, the most common spinal intradural tumor in Northern China is schwannoma, followed by spinal meningioma and ependymoma.

Radiotherapy for central neurocytoma: A multicentric retrospective study in France

PURPOSE

Neurocytomas represent 0.25 to 0.5% of primary brain tumours and are mainly found in young adults. These tumours have neuronal differentiation. The cornerstone treatment is neurosurgery. The efficacy of other therapies, including radiotherapy, is still unclear. The objective of this study was to evaluate the management of central neurocytomas and the role of radiotherapy.

MATERIALS AND METHODS

All adult patients (age 18 years or older) newly diagnosed with a histologically confirmed neurocytoma between 2006 and 2015 in France were included.

RESULTS

One hundred and sixteen patients were diagnosed with a central neurocytoma during the study period. All patients underwent surgical resection, and six received adjuvant radiotherapy. Eleven patients received radiotherapy due to progression. After a median follow-up of 68.7 months, local failure occurred in 29 patients. The 5-year local control rate was 73.4%. According to univariate analysis, marker of proliferation Ki67 index greater than 2% (hazard ratio [HR]: 1.48; confidence interval [CI]: 1.40-1.57; P=0.027) and subtotal resection (HR: 8.48; CI: 8.01-8.99; P<0.001) were associated with an increase in local failure. Gross total resection was associated with a higher risk of sequelae epilepsy (HR: 3.62; CI: 3.42-3.83; P<0.01) and memory disorders (HR: 1.35; CI: 1.07-1.20; P<0.01). Ten patients (8.6%) died during the follow-up. The 10-year overall survival rate was 89.0%. No prognostic factors for overall survival were found.

CONCLUSION

The analysis showed that patients who underwent subtotal surgical resection, particularly when the tumour had a Ki67 index greater than 2%, had an increased risk of local recurrence. These patients could benefit from adjuvant radiotherapy.

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.

Cytopathology of glioneuronal and neuronal tumours with histological correlations

Glioneuronal and neuronal tumours constitute a diverse group of tumours that feature neuronal differentiation. In mixed glioneuronal tumours, a glial component is present in addition to the neuronal component. With a few exceptions (eg diffuse leptomeningeal glioneuronal tumour) they are well-circumscribed and slow-growing tumours, which is why their prognosis is intrinsically favourable after gross total resection. Rendering an intraoperative diagnosis of glioneuronal/neuronal tumour is therefore important-neurosurgeons should remove them to prevent the persistence of clinical symptoms and/or recurrence. In this context, cytopathological examination can be especially useful for assessing cellular details when frozen section artefacts render poor-quality preparations, as is the case for this group of tumours, which are frequently mistaken for infiltrating gliomas (eg diffuse astrocytoma infiltrating grey matter, oligodendroglioma) on frozen section slides. The aim of this article is to review the cytomorphological features of glioneuronal and neuronal tumours according to the 2021 World Health Organization classification of central nervous system tumours, 5th edition. Additionally, since interpretation in intraoperative cytology relies on intuiting tissue patterns from cytology preparations, representative histological figures of all discussed entities have been included. Clues for specific diagnoses and the primary diagnostic problems encountered during intraoperative procedures are also discussed.

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.

Central neurocytomas: research trends, most cited papers, and scientometrics analysis to date

Central neurocytoma is the most common primary intraventricular tumor in adults being classified by the World Health Organization (WHO) as a benign grade II tumor with a good prognosis. Given the recent advances with regard to this tumor, a bibliometric analysis was due to study the future direction of research for neurocytomas. A comprehensive Elsevier's Scopus database search was performed to capture all published and indexed studies to date relevant to neurocytoma. A discrete set of validated bibliometric parameters were extracted and analyzed on R v4.1.3. A total of 1002 documents were included in our analysis covering a period between 1910 and 2021 (111 years). Around 98.5% of the documents were multi-author publications with a collaboration index (CI) of 4.21. Acta Neuropathologica, The American Journal of Surgical Pathology, and Cancer were the journals to include the highest number of top ten cited articles (2 out of 10 most cited articles, 20%). Switzerland (4 out of 10, 40%) accounted for the country to have the highest number of top 10 most cited articles with the USA (5588 out of 16,395 citations, 34.1%) having the greatest number of citations. Lastly, our analysis reported an annual growth rate of 6.9% for the number of papers produced by year. This is the first bibliometric analysis to study the top 10 most cited articles with regard to neurocytomas. A shift from histopathologic and clinical symptoms towards the treatment and management of the tumor was observed in our analysis.

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.

T2 Hypointense Schwannoma Masquerading As A Vascular Lesion: A Case Report

Spinal schwannomas are rare nerve root tumors that typically produce subtle symptoms from nerve root compression. These tumors are known to be heterogeneously hyperintense on T2-weighted MRI and avidly enhance with contrast. However, here we describe an L5 spinal schwannoma in a 66-year-old woman that was hypointense on T2-weighted imaging with other radiographic findings more closely aligning with a vascular lesion. The neuroradiologic characteristics on MRI, time resolved MR angiography, and catheter digital subtraction angiography are presented. The patient underwent a full workup for possible dural arteriovenous fistula and thrombosed venous varix before the nerve sheath tumor was discovered intraoperatively and confirmed as a schwannoma on histopathology.

The role of methylation profiling in histologically diagnosed neurocytoma: a case series

Purpose

To highlight the clinical, neuroradiographic, neuropathologic, and molecular features of histologically identified neurocytoma in a pediatric cohort and highlight the evolving use methylation profiling in providing diagnostic clarity in difficult to diagnosis pediatric brain tumors.

Methods

Five consecutive children (ages 9–13, 2 girls 3 boys) were histologically diagnosed with neurocytoma at Rady Children’s Hospital San Diego from 2012 to 2018. Clinical and molecular features were analyzed with regards to treatment course and outcome.

Results

Presenting symptoms included seizures (n = 2), syncope (n = 1), headache (n = 2), visual disturbances (n = 2) and emesis (n = 2). Tumor location included intraventricular (n = 2), intraventricular with parenchymal spread (n = 1), and extraventricular (n = 2). Magnetic resonance imaging demonstrated reduced diffusivity (2/5), signal abnormality on susceptibility-weighted sequences (3/5), and varying degrees of contrast enhancement (4/5). All patients underwent surgical resection alone. Recurrence occurred in four children that were treated with surgery (4/4), adjuvant radiation (2/4), and chemoradiation (1/4). Neuropathologic features included positivity for GFAP (4/5), synaptophysin (4/5), NSE (2/2), NeuN (4/4), and variable Ki-67 (< 1% to 15%). Next generation sequencing (3/5) and microarray (3/5) collectively were abnormal in four of five tumors. Methylation profiling was successfully performed on four of five samples which led to modification of diagnosis in two patients and the others were either unclassifiable or confirmatory with the histologic diagnosis. Mean time to follow up was 77 months (range 44–112 months). Mean progression free survival and overall survival were 24 months (range 6 to 52 months) and 100% respectively.

Conclusion

Neurocytomas are a rare clinical entity that warrants further investigation into molecular and pathologic prognosticating features. Methylation profiling may aid in differentiation of neurocytoma from other difficult to diagnose tumors who share similar histologic features.

Clinical Outcomes and Prognostic Analysis of 101 Patients of Central Neurocytoma: A 10-Year Treatment Experience at a Single Institution

Objective

Central neurocytoma (CN) is a rare type of tumor that currently lacks an optimal treatment protocol. This study aimed to explore the clinical outcomes of CN in a cohort of 101 patients and identify prognostic factors associated with multiple treatment modalities.

Methods

This monocentric study retrospectively analyzed the clinical data of 101 CN patients who underwent surgical resection. The patients were followed up, and their overall survival (OS) and progression-free survival (PFS) were calculated.

Results

For the entire cohort, the 5- and 10-year OS rates were 88.7% and 82.8%, respectively, and the 5- and 10-year PFS rates were 86.5% and 64.9%, respectively. Of the 82 (81.19%) patients with CN who underwent gross total resection (GTR), 28 (28/82, 34.1%) also received radiotherapy (RT). Of the 19 (18.81%) patients with CN who underwent subtotal resection (STR), 11 (11/19, 57.9%) also received RT or stereotactic radiosurgery (SRS). Compared to STR, GTR significantly improved the 5-year OS (92.4% vs. 72.4%, P=0.011) and PFS (92.4% vs. 60.4%, P=0.009) rates. Radiotherapy did not affect OS in the GTR group (p=0.602), but it had a statistically significant effect on OS in the STR group (P<0.001). However, the OS (P=0.842) and PFS (P=0.915) in the STR plus radiotherapy group were comparable to those in the GTR alone group. Compared to STR alone, STR plus radiotherapy improved the 5-year PFS rate from 25% to 75% in patients with atypical CN (P=0.004). Cox regression models and a competing risk model showed that the removal degree and radiotherapy were independent prognostic factors for survival. With improvements in modern radiotherapy techniques, severe radiotherapy toxicity was not observed.

Conclusion

Our findings support the use of GTR whenever possible. Radiotherapy can improve the prognosis of patients who undergo STR, especially in atypical CNs having a higher tendency to relapse. Close imaging follow-up is necessary. Our findings will help clinicians to select optimal, individualized treatment strategies to improve OS and PFS for patients with CN.

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.

Extraventricular neurocytomas: a systematic review of the literature in the pediatric population

Extraventricular neurocytomas (EVNs) are rare neuroepithelial neoplasms of the central nervous system that were first described in 1997. Most studies in patients with EVNs have incorporated mixed age groups. The tumor's clinical behavior specifically in children has not been explored in depth, while a detailed statistical analysis has never been performed in this age group. Hence, we performed a systematic review to address possible prognostic factors and the appropriate management in children with EVNs. Relevant studies were identified by searching the MEDLINE and SCOPUS databases. We included studies concerning patients 18 years of age or younger who were histologically diagnosed with EVNs. A total of 52 studies with 79 patients were included. The mean age of the patients was ~ 10 years with a male predilection (~ 2:1). Most of these tumors were located in the frontal (49%) lobe. We observed that gross total resection of the tumor was significantly lower in cases of atypical EVNs (p < 0.05). Additionally, atypical EVNs were associated with worse overall survival compared to typical EVNs (p = 0.05). Children 4 years of age or under had a worst outcome (p = 0.001). The patient's sex and the extent of the tumor's resection did not appear to affect the prognosis in a statistically significant manner. Contrary to the results of previous studies, the use of adjuvant radiotherapy or chemotherapy for the treatment of EVNs was not associated with better outcomes in the pediatric population. Thus, a less aggressive management of children with EVNs compared to the adult population is suggested.

Extraventricular Neurocytoma in Parietal Lobe

Extraventricular neurocytoma (EVN) was classified as a World Health Organization (WHO) grade II tumor; however, EVN is not fully understood; it presents a variable histological feature that included oligodendroglioma-like, neuropil-like matrix, ganglion or gangloid cells, perivascular pseudorosettes, vessel hyalinization, calcifications, and myxoid degeneration. In some very rare cases, atypical histological features such as increased mitotic figures, focal necrosis, endothelial cell proliferation, and Ki-67 index of >2% made this tumor more aggressive and more susceptible to recur. We present the case of a young patient who presents with a 2-year history of seizure without other symptoms. Magnetic resonance imaging reveals a parietal lobe and well-circumscribed lesion treated by gross total resection and adjuvant radiotherapy. Clear guidelines to treat this kind of lesions are not well established and there is not a consensus of correct treatment in these tumors.

Gamma Knife radiosurgery as a primary treatment for central neurocytoma

OBJECTIVE

This study was performed to evaluate the role of Gamma Knife radiosurgery (GKRS) as a primary treatment for central neurocytomas (CNs).

METHODS

The authors retrospectively assessed the treatment outcomes of patients who had undergone primary treatment with GKRS for CNs in the period between December 2001 and December 2018. The diagnosis of CN was based on findings on neuroimaging studies. The electronic medical records were retrospectively reviewed for additional relevant preoperative data, and clinical follow-up data had been obtained during office evaluations of the treated patients. All radiographic data were reviewed by a dedicated neuroradiologist.

RESULTS

Fourteen patients were treated with GKRS as a primary treatment for CNs in the study period. Seven patients (50.0%) were asymptomatic at initial presentation, and 7 (50.0%) presented with headache. Ten patients (71.4%) were treated with GKRS after the diagnosis of CN based on characteristic MRI findings. Four patients (28.6%) initially underwent either stereotactic or endoscopic biopsy before GKRS. The median tumor volume was 3.9 cm3 (range 0.46–18.1 cm3). The median prescription dose delivered to the tumor margin was 15 Gy (range 5.5–18 Gy). The median maximum dose was 30 Gy (range 11–36 Gy). Two patients were treated with fractionated GKRS, one with a prescription dose of 21 Gy in 3 fractions and another with a dose of 22 Gy in 4 fractions. Control of tumor growth was achieved in all 14 patients. The median volume reduction was 26.4% (range 0%–78.3%). Transient adverse radiation effects were observed in 2 patients but resolved with improvement in symptoms. No recurrences were revealed during the follow-up period, which was a median of 25 months (range 12–89 months).

CONCLUSIONS

Primary GKRS for CNs resulted in excellent tumor control rates without recurrences. These results suggest that GKRS may be a viable treatment option for patients with small- to medium-sized or incidental CNs.

Olfactory neurocytoma as a unique cause of chronic SIADH

A 32-year-old man was found to have a nasal mass on DOTATATE positron emission tomography (PET) scan to investigate the cause of his syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient presented 6 years earlier with malignant hypertension followed by a second emergency admission for hyponatraemia. Multiple scans and blood tests over 6 years yielded no cause for his SIADH. Nasendoscopy was unremarkable. A PET scan prompted endoscopic sinus surgery which resulted in the resection of a mass in the anterior hiatus semilunaris. The histological findings were fitting with a diagnosis of a neurocytic-type tumour favouring an olfactory neurocytoma. Following resection, the patient remains well and is cured of his SIADH. An olfactory neurocytoma although rare should be considered as a benign differential for a mass in the nasal space. This case demonstrates how an olfactory neurocytoma can present as a cause of SIADH.

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.

Neurological outcome after resection of spinal schwannoma

INTRODUCTION

Spinal schwannoma (SS) is the most frequently diagnosed benign spinal tumor, constituting approximately 25 % of all intradural tumors. Aim of our study was to identify factors that potentially affect immediate postoperative neurological outcome, and the rate of functional recovery within 12 months.

METHODS

Screening of our institutional database yielded 90 consecutive patients (mean age 57.1 years, 39 women [43.3 %]) with newly diagnosed SS between March 1997 and October 2018. We pre- and postoperatively reviewed patient charts, surgical reports, radiographic data, use of IOM, duration of symptoms, histopathology, co-morbidities, radiographic extension, surgical strategy, neurological performance (Japanese Orthopedic Association Score [JOA score] and Frankel Grade Classification).

RESULTS

Mean duration of preoperative symptoms was 3.6 ± 1.6 months. Most common symptoms were local pain (n = 77, 85.6 %). Macroscopic complete resection was achieved in 84 patients (93.3 %). During follow-up, complete recovery from local pain was documented for 41 patients (59.7 %), from radiating pain for 41 (69.5 %; p < 0.001). Postoperatively, 25 (27.7 %) patients developed a new neurological deficit (motor deficits n = 3 and sensory deficits n = 23; one patient developed both); after 12 months, however, motor deficits had abated in all patients, and 16 (69.5 %) patients had completely recovered from sensory deficits. Use of intraoperative monitoring (IOM) was a significant predictor for good functional outcome (p < 0.001).

CONCLUSION

Resection of SS accompanied by IOM whenever feasible should be advocated. We achieved a high number of complete resections with a low rate of morbidity. New postoperative motor or sensory deficits had a very high rate of complete recovery within 12 months.

[Choice optimisation of radiation therapy technique for central neurocytomas from literature data]

Neurocytomas represent 0,25 to 0,5 of brain tumours. These tumours have neuronal differentiation. It's a young adult disease. The main treatment is neurosurgery. The place of other therapies is still unclear, noticeably with regards to radiotherapy. This review aim is to determine the place and the modalities of radiotherapy in the management of neurocytomas. A literature search using PubMed allowed to select the most relevant studies. Finally, 22 studies were selected according to pre-established criteria to answer the problem. All studies were retrospective studies except one. The analysis conclusion defined radiotherapy as a treatment of choice in selected patients, when surgical resection was incomplete or when tumour was atypical.

Imaging of extraventricular neurocytoma: a systematic literature review

OBJECTIVE

Extraventricular neurocytoma (EVN) was firstly described in 1997. The current literature regarding imaging of EVN is limited to sporadic case reports and case series. EVN is still poorly considered in the differential diagnosis by neuroradiologists, thus diagnosis remains challenging. In this systematic review, we summarize and discuss computed tomography (CT) and magnetic resonance imaging (MRI) features of EVN cases described in the literature, in order to provide useful informations to neuroradiologists. To the best of our knowledge, this is the most extensive review about imaging of EVN.

MATERIALS AND METHODS

A systematic review of the literature about imaging of EVN cases was done. Only case reports or case series in which imaging (CT and/or MRI) features were deeply described were included in the revision. Eligibility of studies was assessed independently by two authors and any disagreements resolved by discussion.

RESULTS

Our search strategy revealed 224 articles. After implementation of inclusion and exclusion criteria, 35 studies were considered, and a total of 79 cases of EVN were analyzed.

CONCLUSION

EVN has not specific characteristics, with a large and variable imaging spectrum. Usually it appears as a large tumor, with diameters superior to 40 mm, frequently involving the frontal lobe. CT density and MRI signal intensity typically mirror the presence of cystic, solid, or calcified elements; contrast enhancement is visible in 87% of cases. Today, diagnosis of EVN with only imaging techniques is not univocal; neuroradiologists can only suspect this type of lesion, while the definitive diagnosis remains histological.

The epidemiology of spinal schwannoma in the United States between 2006 and 2014

OBJECTIVE

Spinal schwannoma remains the third most common intradural spinal tumor following spinal meningioma and ependymoma. The available literature is generally limited to single-institution reports rather than epidemiological investigations. As of 1/1/2004, registration of all benign central nervous system tumors in the United States became mandatory after the Benign Brain Tumor Cancer Registries Amendment Act took action, which provided massive resources for United States population-based epidemiological studies. This article describes the epidemiology of spinal schwannoma in the United States from January 1, 2006, through December 31, 2014.

METHODS

In this study, the authors utilized the Central Brain Tumor Registry of the United States, which corresponds to 100% of the American population. The Centers for Disease Control and Prevention's National Program of Cancer Registries and the National Cancer Institute's Surveillance Epidemiology and End Results program provide the resource for this data registry. The authors included diagnosis years 2006 to 2014. They used the codes per the International Coding of Diseases for Oncology, 3rd Edition: histology code 9560/0 and site codes C72.0 (spinal cord), C70.1 (spinal meninges), and C72.1 (cauda equina). Rates are per 100,000 persons and are age-adjusted to the 2000 United States standard population. The age-adjusted incidence rates and 95% confidence intervals are calculated by age, sex, race, and ethnicity.

RESULTS

There were 6989 spinal schwannoma cases between the years 2006 and 2014. The yearly incidence eminently increased between 2010 and 2014. Total incidence rate was 0.24 (95% CI 0.23-0.24) per 100,000 persons. The peak adjusted incidence rate was seen in patients who ranged in age from 65 to 74 years. Spinal schwannomas were less common in females than they were in males (incidence rate ratio = 0.85; p < 0.001), and they were less common in blacks than they were in whites (IRR = 0.52; p < 0.001) and American Indians/Alaska Natives (IRR = 0.50; p < 0.001) compared to whites. There was no statistically significant difference in incidence rate between whites and Asian or Pacific Islanders (IRR = 0.92; p = 0.16).

CONCLUSIONS

The authors' study results demonstrated a steady increase in the incidence of spinal schwannomas between 2010 and 2014. Male sex and the age range 65-74 years were associated with higher incidence rates of spinal schwannomas, whereas black and American Indian/Alaska Native races were associated with lower incidence rates. The present study represents the most thorough assessment of spinal schwannoma epidemiology in the American population.