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

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

Prognosis and treatment outcomes of central neurocytomas: clinical interrogation based on a single center experience.

INTRODUCTION: Central neurocytoma (CN) is a very rare neuronal neoplasm. The clinical implications of the potential prognostic factors for these lesions, including tumor atypia, have therefore not been clarified. METHODS: Forty CN patients were enrolled and reclassified as typical or atypical in accordance with an MIB-1 labeling index (LI) of above and below 2%. RESULTS: We classified our retrospective study cohort as 21 (52.5%) typical and 19 (47.5%) atypical CN cases. No significant differences were found in terms of sex, mean age, mean tumor size or tumor location between these groups. Recurrences occurred in 2 (9.5%) typical and 6 (33.3%) atypical cases. The typical CN 2-,3- and 5-year PFS rates were 100%, 100%, 92.3%, and those for the atypical group were 93.8%, 78.1%, 65.1%, respectively (p = 0.02). The PFS rates did not statistically differ by treatment modality (gross total resection alone, subtotal resection (STR) alone and STR plus radiation therapy (RT) or radiosurgery (RS)) either in the whole cohort (p = 0.75) or in the typical CN and atypical CN subgroups (p = 0.45 and 0.98, respectively). An atypical histology was the only prognostic indicator of recurrence by univariate analysis (hazard ratio: 5.40, p = 0.04). CONCLUSIONS: An atypical lesion (MIB-LI > 2%) is an important prognostic indicator in CN. The clinical implications of the extent of resection for CN patients are still debatable. The use of STR plus RT or RS may be a viable treatment strategy for CN but different therapeutic and follow-up approaches for atypical CN will be needed.

Imaging characteristics of cerebral extraventricular neurocytoma with pathological correlation.

PURPOSE: Extraventricular neurocytoma (EVN) is an exceedingly rare tumor. In this study, we sought to characterize the imaging and pathological features of this uncommon tumor. METHODS: Retrospective review of 18 patients (9 male; 9 female) with pathologically confirmed EVN treated at a single center between 2005 and 2017. RESULTS: All patients had a solitary lesion. Sixteen lesions were found in hemispheres. The greatest tumor diameter ranged from 2.6 to 8 cm. The lesions were generally solid with cystic components; the solid portion appeared isodense or hyperdense on CT, isointense to hypointense on T1WI, and slightly hyperintense on T2WI. Heterogeneous hyperintensity interspersed with isointense or hypointense areas suggestive of hemorrhage, calcification or vascular flow voids were seen on T2WI. Heterogeneous enhancement was noted in 17 lesions; no enhancement was observed in one lesion. Cystic components were observed in 13 lesions; 9 of these showed characteristic perilesional cysts (9/13). Mild to moderate peritumoral edema (15/18), calcification (4/16), intratumoral hemorrhage (11/18) and vascular flow voids (10/16) were observed in some lesions. Pathologically, tumor cells showed round nucleus and fine neuropil matrix. Foci of calcification in the solid portion of the tumor were seen in five cases. Microcystic changes were observed in almost all cases. Some lesions exhibited positive staining for synaptophysin (Syn) (15/16) and neuronal nuclei (NeuN) (7/8). MIB-1 was determined for 10 patients; seven of these had an MIB-1 ≥ 3. These six patients experienced recurrence; four of them relapsed twice. CONCLUSIONS: EVNs occur as single intracranial solid mass with cystic components (especially peripherally located cysts); solid portion exhibits slight hyperintensity or heterogeneous signal intensity. Mild to moderate peritumoral edema, calcification, intratumoral hemorrhage and vascular flow voids were characteristic features of extraventricular neurocytoma. Positive staining for synaptophysin and neuronal nuclei confirmed the diagnosis. A combination of atypical pathologic features and atypical radiologic features should be considered for prognostic assessment.

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.

Central, Extraventricular and Atypical Neurocytomas: a Clinicopathologic Study of 35 Cases from Pakistan Plus a Detailed Review of the Published Literature.

BACKGROUND: Central neurocytomas are rare neuronal neoplasms with a favorable prognosis. They are typically located in the lateral ventricles of the brain and mostly histologically correspond to WHO grade II with a Mib 1 labelling index of <2%. Similar tumors located in the cerebral hemispheres and spinal cord, for example, are called "extraventricular neurocytomas". A few tumors histologically show atypia, mitoses, vascular proliferation and/or necrosis and a Mib 1 index >2 % and are designated as "atypical neurocytomas. AIM: The aim of our study was to describe the common as well as unusual morphologic features and the role of various immunohistochemical stains in the diagnosis of these rare tumors. MATERIALS AND METHODS: We retrieved and reviewed 35 cases diagnosed between 2001 and 2015. RESULTS: Sixty percent of patients were males, and the mean age was 26 years. 31 cases (88.6%) were intraventricular and 4(11.4%) were extraventricular. Histologically, 6 cases (17.1%) were compatible with "atypical neurocytomas". All cases showed the classic morphology comprising nests and sheets of uniform, round cells with uniform round to oval nuclei with finely speckled chromatin and perinuclear cytoplasmic clearing (halos). All cases also showed delicate, fibrillary, neuropil-like matrices. Other common histologic features included capillary-sized blood vessels in a branching pattern in 57.1%, foci of calcification in 34.3% and perivascular pseudorosettes in 20%. Rare findings included Homer- Wright or true rosettes in 8.6% and ganglioid cells in 2.9%. Synaptophysin was the most consistent and valuable marker, being positive in almost all cases. GFAP positivity in tumor cells was seen in 25.7% of cases. Follow up was available in 13 patients. Of these 9 had histologically typical and 4 had atypical tumors. Only 1 (with an atypical neurocytoma) died, probably due to complications of surgery within one month, while 12 (including 3 with atypical neurocytomas) remained alive. Recurrence developed in 1 of these 12 patients (histologically consistent with typical morphology) almost 9 years after surgery. Only 4 patients, including 2 with atypical tumors, received postoperative radiotherapy, all with surgery in 2010 or later. Overall, prognosis was excellent with prolonged, recurrence free survival and most patients, even without receiving radiation therapy, were alive and well for many years, even a decade or more after surgery, without developing any recurrence, indicating the benign nature of these neoplasms.

Primary spinal neurocytoma involving the medulla oblongata: two case reports and a literature review.

Central neurocytoma is a rare neuroectodermal tumor found in young adults. These tumors are generally located in the lateral or third ventricles. Extraventricular neurocytoma in the spinal cord is extremely rare. We report on two patients with primary spinal neurocytomas who presented with progressive numbness and weakness in the limbs. Both patients had intramedullary masses between the medulla and the upper thoracic levels. The clinical, radiological, surgical, and pathological features of this abnormality are discussed, and all 20 reported cases were reviewed. In conclusion, neurocytoma should be included in the differential diagnosis of a spinal intramedullary tumor, and subtotal resection is acceptable for a relatively favorable prognosis if gross total removal is unachievable. The efficacy of adjuvant radiochemotherapy to control tumor recurrence is unknown.

Cerebellar liponeurocytoma: case report.

Liponeurocytoma (lipomatous medulloblastoma) is a rarely and recently described tumor. We report an additional case of this uncommon lesion in an adult and we describe its clinical, radiological and histological features. A 45-year-old woman presented with symptoms and signs of increased intracranial pressure and cerebellar dysfunction. Computed tomography (CT) and magnetic resonance imaging (MRI) scans showed a heterogenous poorly circumscribed mass situated within the cerebellar vermis. After complete tumour resection, pathologic examination with immunohistochemical study confirmed the diagnosis. The postoperative course after 18 months was favorable with no evidence of tumor recurrence.

Central neurocytoma.

Central neurocytomas (CN) are rare intraventricular tumors with prominent neuronal differentiation. CN commonly arise in the lateral ventricles of young adults who predominantly present with raised intracranial pressure. Few studies have described the clinical, pathological, and radiological features of these tumors, and those that have are typically single case reports. Herein, we report ten patients with CN with variable clinical and pathological features and discuss the management of these tumors. Nine tumors occupied the lateral ventricle and only one was located in the sellar region. On MRI, all 10 tumors showed heterogeneous hypo-or iso-intensity on T1-weighted and hyperintensity on T2-weighted MRI. Contrast enhancement varied greatly from very slight to intense. All patients were surgically treated by macroscopic total or subtotal removal. Postoperative radiotherapy was given to six patients (four of whom had undergone subtotal resection and two of whom had undergone total resection). The surgical and histopathological data of these patients were reviewed and analyzed. No recurrences were noted although we were unable to contact two patients for follow-up. A brief review of the literature concerning differential diagnosis and therapeutic aspects of these tumors is also presented.

[Central neurocytomas of the lateral ventricle. A series of 35 cases with review of the literature]. / Les neurocytomes centraux du ventricule latéral. Analyse d'une série de 35 cas et revue de la littérature.

Central neurocytoma is the second most frequent tumor in our series of 284 lateral ventricle tumors (12%). Mean age was 32.6 years. There was a male predominance (20/35). Most frequent clinical signs were neuropsychological disturbances and intracranial hypertension. On imaging, these tumors concentrate central calcifications in more than half of cases. Main locations were frontal horn and corpus of lateral ventricle (82%). Uneventful postoperative course was recorded in 52% of cases. Immunoreactivity against neuron-specific enolase (NSE), synaptophysin, S100 protein, Microtubul Associated Protein de type 2 (MAP2) and calcineurin confirms the neuronal nature of the neoplasm. This tumor has a good prognosis. Local control after surgery is obtained in 68% of cases. Gamma knife surgery seems to be useful in cases of little volume with tumoral remnants or recurrence, when radiological appearance is well circumscribed and round-shaped.

Central neurocytoma: a multi-disciplinary review.

Benign central neurocytoma (CN) is a rare neuronal tumour of the central nervous system recognised since the early eighties. More than 300 articles have been published in the literature, mostly comprising of case reports and short series from individual specialties. These tumours, though normally benign, are more often likely to recur after surgery than previously thought. A multi-modality team involvement, therefore, has become increasingly necessary for their optimum management. In this article, the authors from various neurosciences sub-specialties, with a specific interest and experience in managing CN, review the epidemiology, clinical features, pathological findings, radiological characteristics and surgical treatment, with an emphasis on the latest developments in their histology, molecular biology and adjuvant treatment modalities for recurrent or residual disease.

Neurocytoma: a comprehensive review.

Central neurocytomas (CN) are uncommon tumors of the central nervous system, most descriptions of which available in the literature are in the form of isolated case reports and small series. Owing to this rare incidence, diagnosis and management of this neoplasm remain controversial. Usually, these tumors affect lateral ventricles of young adults and display characteristic neuroimaging and histomorphologic findings. Neurocytomas often mimic oligodendrogliomas when confirmation of diagnosis rests on immunohistochemistry, ultrastructure, and genetic studies. Extraventricular neurocytomas, situated entirely within the brain parenchyma and spinal cord, have also been reported. Typically, CN are associated with a favorable outcome although cases with more aggressive clinical course with recurrences are not unknown. MIB-1 labeling index (LI) of >2% often heralds poor prognosis and tumour recurrence. Safe maximal resection is presently considered the ideal therapeutic option, with best long-term prognosis in terms of local control and survival. The role of adjuvant radiotherapy apparently seems to benefit patients with incomplete resection and in atypical neurocytoma. Utility of other therapeutic regimen, however, remains shrouded in controversy. Epidemiology, histogenesis, clinical profile, histology, neuroimaging and therapeutic modalities of neurocytomas have been comprehensively reviewed, with special emphasis on CN and extraventricular neurocytomas and their atypical counterparts.

Recurrent central neurocytomas.

BACKGROUND: Since the first description of Central neurocytomas (CNs) as a benign tumor entity in 1982, there has been great enthusiasm regarding the benign course and the curative surgical approach to this disease. The current study was performed to investigate the frequency of disease recurrence during long-term follow-up. METHODS: A retrospective analysis of the medical files with emphasis on clinicoradiologic findings and histologic and immunohistochemical features was performed. RESULTS: Between 1985-2003. surgical resection was performed in 14 patients with CNs ages 16-43 years (7 were female and 7 were male). Two patients (14%) died postoperatively and one patient had a malignant disease course (7%). In the remaining 11 patients, one patient with an incompletely resected CN had disease progression after 37 months but at the time of last follow-up had had stable disease for 10 years. In addition, the authors reported 5 patients with disease recurrence occurring at a median of 67 months after surgery (range, 51-79 months after surgery), all of which occurred after complete surgical resection was performed. The observation period for the remaining 5 patients was short (median of 34 months [range, 5-44 months]). Extensive histologic and immunohistochemical workup did not identify any significant prognostic parameters. The MIB-1 proliferation index ranged from 0.8-11% (median of 4.6%), but was reported to be 46.8% in the malignant transformed tumor. All patients with disease recurrence responded well to different forms of focal radiation therapy (gamma knife radiosurgery in three patients and interstitial irradiation in one patient) and for one patient with a recently detected recurrence, gamma knife radiosurgery was planned. CONCLUSIONS: CNs appear to have a higher tendency to recur during long-term follow-up than previously reported, even after complete resection. Therefore, periodic neuroradiologic follow-up examinations should be considered mandatory in all patients, even after several years.

Cns tumors at AKU: an update plus a brief discussion on intraventricular tumors with special emphasis on central neurocytoma.

BACKGROUND: This paper is intended to be an update of our earlier published work on CNS tumors along with additional information on intraventricular tumors. Three cases of central neurocytoma are also discussed. METHODS: An analysis conducted in the Section of Histopathology, AKU to determine the frequency of all CNS neoplasms diagnosed between Jan 1, 1994 and Dec 31, 2001. Frequency of intraventricular tumors was also determined. Histological characterization of the tumors was based on the WHO and AFIP (USA) classification systems for CNS tumors. RESULTS: A total of 1677 CNS tumors were diagnosed during the study period. 1510(90.04%) were primary, and 167(9.96%) were metastatic. Among the primary tumors, gliomas constituted the largest category with 825 cases or 54.63% of all primary tumors. Meningothelial tumors comprised the second largest group with 364 cases or 24.10%. among other major categories, embayonal tumors, and peripheral nerve sheath tumors comprised 6.75% and 6.82% of all primary tumors. Among less common tumors, Non-Hodgkin's lymphomas and hemangioblastomas comprised 3.11% and 1.52% of all CNS tumors. Intraventricular tumors comprised 7.41% of all primary tumors. Ependymomas comprised 64.28% of all Intraventricular tumors. CONCLUSIONS: Gliomas and meningothelial tumors are the commonest group of primary CNS tumors. Metastatic tumors are quite common.

Intraventricular neurocytoma.

Intraventricular neurocytoma is a rare cerebral tumour which is usually associated with a good prognosis. It has imaging features which help differentiate it from other cerebral tumours. We report three cases including the first to originate from the pineal gland. The report emphasizes the radiological appearance and reviews the literature.