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We explored the genomic events underlying central neurocytoma (CN), a rare neoplasm of the central nervous system, via multiomics approaches, including whole-exome sequencing, bulk and single-nuclei RNA sequencing, and methylation sequencing. We identified FGFR3 hypomethylation leading to FGFR3 overexpression as a major event in the ontogeny of CN that affects crucial downstream events, such as aberrant PI3K-AKT activity and neuronal development pathways. Furthermore, we found similarities between CN and radial glial cells based on analyses of gene markers and CN tumor cells and postulate that CN tumorigenesis is due to dysregulation of radial glial cell differentiation into neurons. Our data demonstrate the potential role of FGFR3 as one of the leading drivers of tumorigenesis in CN., (© 2024. The Author(s).)

Almost any primary or metastatic brain tumour can manifest in intraventricular (IV) locations. These tumours may either originate within the ventricular system or extend into the IV space through growth. Such neoplasms represent a broad spectrum, with supratentorial IV tumours forming a heterogeneous group. This group includes primary ependymal tumours, central neurocytomas, choroid plexus tumours, and notably, meningiomas, as well as a variety of non-neoplastic, benign, glial, and metastatic lesions that can secondarily invade the IV compartment. Often presenting with nonspecific symptoms, these tumours can lead to delayed medical attention. The diversity in potential diagnoses, combined with their deep and complex locations, poses significant management challenges. This paper aims to delineate optimal management strategies, underscoring the importance of multidisciplinary care, especially in settings with limited resources, to effectively navigate the complexities associated with treating intraventricular brain tumours.

Central neurocytoma (CN) is a low-grade neuronal tumor that mainly arises from the lateral ventricle (LV). This tumor remains poorly understood in the sense that no driver gene aberrations have been identified thus far. We investigated immunomarkers in fetal and adult brains and 45 supratentorial periventricular tumors to characterize the biomarkers, cell of origin, and tumorigenesis of CN. All CNs occurred in the LV. A minority involved the third ventricle, but none involved the fourth ventricle. As expected, next-generation sequencing performed using a brain-tumor-targeted gene panel in 7 CNs and whole exome sequencing in 5 CNs showed no driver mutations. Immunohistochemically, CNs were robustly positive for FGFR3 (100%), SSTR2 (92%), TTF-1 (Nkx2.1) (88%), GLUT-1 (84%), and L1CAM (76%), in addition to the well-known markers of CN, synaptophysin (100%) and NeuN (96%). TTF-1 was also positive in subependymal giant cell astrocytomas (100%, 5/5) and the pituicyte tumor family, including pituicytoma and spindle cell oncocytoma (100%, 5/5). Interestingly, 1 case of LV subependymoma (20%, 1/5) was positive for TTF-1, but all LV ependymomas were negative (0/5 positive). Because TTF-1-positive cells were detected in the medial ganglionic eminence around the foramen of Monro of the fetal brain and in the subventricular zone of the LV of the adult brain, CN may arise from subventricular TTF-1-positive cells undergoing neuronal differentiation. H3K27me3 loss was observed in all CNs and one case (20%) of LV subependymoma, suggesting that chromatin remodeling complexes or epigenetic alterations may be involved in the tumorigenesis of all CNs and some ST-subependymomas. Further studies are required to determine the exact tumorigenic mechanism of CN., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To determine the MR (magnetic resonance), pathologic, and clinical findings of extraventricular neurocytoma (EVN)., Study Design: Descriptive study., Place and Duration of Study: Department of Radiology, Affiliated Hospital of Jining Medical University, Jining, Shandong, China, from January 2020 to March 2022., Methodology: The MR radiological and pathological data of 11 patients with EVNs proved by histopathology after surgery were analysed retrospectively. Above-mentioned features were studied., Results: There were 5 men and 6 women, ages ranging from 16 to 56 years. Seven cases (63.6%) were located in the cerebral hemisphere, three cases (27.3%) in the cerebellar hemisphere, and one case in cervical cord. Ten cases (91.0%) were cystic-solid, and one case was predominantly solid with small cystic components. Six cases (54.5%) had mild peritumoural ooedema. The signal was isointense (8/11, 72.7%) or hypointense (3/11, 27.3%) on T1WI, and isointense (1/11, 9.1%) or hyperintense (10/11, 90.9%) on T2WI; all cases showed hyperintense on FLAIR and restricted diffusion on DWI. Haemorrhage was found in two cases (18.2%) and flow-void was found in one case (9.1%). All the tumours demonstrated contrast enhancement., Conclusion: An accurate diagnosis of EVN is difficult to be made preoperatively. It should be considered when a solid-cystic tumour with the solid part showing isointense on T1WI, hyperintense on FLAIR with mild to moderate enhancement especially restricted diffusion on DWI sequence in patients aged 20-30. When the radiologic manifestations are atypical, more aggressive treatment should be chosen., Key Words: Neurocytoma, Extraventricular, Clinical, Imaging characteristics, MRI.

Competing Interests: Competing interests: None declared.

Background: Central neurocytomas represent 0.25-0.5% of all intracranial tumors in adults. Leptomeningeal spread is uncommon, and the exact incidence of meningeal spread is unknown due to sparse literature. We present the clinical course and management outcome of a case of atypical central neurocytoma with leptomeningeal spread., Case Presentation: A young gentleman, who initially presented with memory loss, was found to have a right intra-axial periventricular mass on imaging. He underwent subtotal resection, and operative histopathology suggested a periventricular atypical neurocytoma. In view of subtotal resection, adjuvant focal radiation therapy was recommended, but he developed headache and blurring of vision 10 days postoperatively. Contrast enhanced craniospinal magnetic resonance imaging (MRI) showed residual primary tumor as well as diffuse leptomeningeal spread. Cerebrospinal fluid cytology also showed malignant cells. After tumor board discussion, craniospinal axis irradiation was advised and delivered. He remained disease-free for 10 months after radiation therapy, but then developed local and spinal recurrence, and offered salvage chemotherapy. His general condition deteriorated following chemotherapy with disease progression, and he was subsequently advised best supportive care., Conclusion: Leptomeningeal dissemination in atypical neurocytomas portends an aggressive course and adverse prognosis; management decisions may need tailoring as per individual presentation.

To describe the far-anterior interhemispheric transcallosal approach for the treatment of a central neurocytoma at the roof of the lateral ventricle. In comparison to the view obtained during the usual anterior transcallosal approach, the far-anterior approach allowed for a higher view of the lateral ventricle to be obtained without further injury or retraction of the corpus callous. Two patients with central neurocytoma in the lateral ventricle were treated with the far-anterior interhemispheric transcallosal approach. Gross-total resections were achieved in both the patients without any postoperative neurological impairments by only 2-3 cm incisions of the corpus callosum. With the anterior transcallosal approach, which was usually used for the intraventricular tumors, the surgical view was relatively downward into the lateral ventricle and suitable for the resection of the tumors located at the base of the lateral ventricle or even in the third ventricle through the foramen of Monro. However, it was relatively difficult to reach the roof of the lateral ventricle using this approach. In contrast, the surgical corridor of the far-anterior transcallosal approach reaches upward to the roof of the lateral ventricle. The far-anterior transcallosal approach provides an alternative to reach the lesions, especially those located in the upper region of the lateral ventricle near important structures, such as the pyramidal tracts.

Aim: Central neurocytoma (CN) is a rare WHO grade II central nervous system (CNS) tumor. This is an update on chemotherapeutic agents used in its treatment. Patients & methods: An institutional review board-approved, chart review of patients seen at our institution resulted in a single case treated with chemotherapy and is herein included. We proceeded with a comprehensive literature review. Results: We identified 18 citations, representing 39 cases of adult and pediatric CN treated with chemotherapy. With the addition of our single case, the total number of recurrent CN patients treated with temozolomide (TMZ) is nine. Conclusion: There exists marked heterogeneity in chemotherapy used to treat CN. TMZ is incorporated into treatment regimens in the setting of tumor recurrence: its role merits further study.

Rationale: Central neurocytoma is rare benign tumor that occurs in high probability in young adults in the lateral ventricle. Herein, we report an unusual case of an elderly woman who was diagnosed with central neurocytoma isolated to the third ventricle. This deeply located tumor was effectively treated using gamma knife radiosurgery (GKR)., Patient Concerns: A 79-year-old woman was admitted to hospital with gait disturbance and cognitive dysfunction., Diagnosis: Brain magnetic resonance imaging (MRI) revealed a homogenously enhancing multilobulated mass in the posterior third ventricle measuring 1.8 cm in size. The tumor was diagnosed as a central neurocytoma isolated to the third ventricle., Interventions: Neuronavigation-guided endoscopic third ventriculostomy and biopsy were performed. One week following surgery, GKR was performed using a prescribed dose of 14 Gy with 50% isodose lines, and a target volume of 1.62 cc., Outcomes: Three months after GKR, brain MRI revealed a decrease in the size (to 1.4 cm) of the multilobulated strong enhancing mass in the posterior third ventricle, and the patient's symptom of confusion was improved., Lessons: Previous studies have reported that tumors in unusual locations, such as those isolated to the third ventricle, are different according to age, either in young children or elderly individuals. Although complete surgical resection is an effective treatment for central neurocytoma, it is often difficult to approach these tumors through surgery. GKR could, therefore, be an alternative primary treatment option for deeply located central neurocytomas in elderly patients.

Background: Cerebellar liponeurocytoma is a rare tumor of the central nervous system occurring mainly in the posterior fossa, which shows neuronal and variable astrocytic differentiation with foci of lipomatous differentiation. Liponeurocytoma develops in adult patients and is defined in the World Health Organization classification of 2016 as a rare benign grade II tumor., Case Presentation: A 39-year-old Italian man presented to our department suffering from headache and nausea. Magnetic resonance imaging revealed a right-sided cerebellar lesion showing poor contrast enhancement without an obstructive hydrocephalus. Surgery was indicated and total tumor resection was achieved. He was discharged without any neurological deficits. Histopathological examinations revealed a cerebellar liponeurocytoma. A neurological follow-up examination revealed no neurological deficit directly after surgery and 1 year later. Radiotherapy was recommended at the neurooncological board despite the total removal of the tumor, but our patient refused adjuvant radiotherapy. Magnetic resonance imaging of his neurocranium with and without contrast enhancement 48 hours after surgery and 15 months after surgery showed no residual tumor., Conclusions: Liponeurocytomas are rare benign tumors occurring in the majority of cases in the cerebellum. The therapy of choice is surgery. Postoperative radiotherapy has to be discussed individually, but seems to be sufficient if complete tumor resection is not achieved or in cases of a tumor recurrence.

Rationale: Cerebellar liponeurocytoma is a rare tumor of the central nervous system (CNS) characterized by low proliferation but high likelihood of recurrence. Because of its rarity and the paucity of systematic follow-up, the biological behaviors and clinical features of this tumor are still poorly understood. We herein reported a case of cerebellar liponeurocytoma originating in the cerebral hemisphere., Patient Concerns: A 11-year-old male with intermittent headache, nausea, and vomiting. The first computed tomography revealed a large mass in the right cerebral hemisphere. He was transferred to our institution for neurosurgical treatment., Diagnosis: Magnetic resonance imaging showed a large cystic-solid mass in the right frontal lobe with obvious contrast enhancement. Histopathological examinations showed sheets of isomorphic small neoplastic cells with clear cytoplasm and focal lipomatous differentiation. On immunohistochemistry, tumor cells were positive for synaptophysin, microtubule-associated protein 2, and neuronal nuclei antigen., Interventions: The patient was performed a right fronto-parietal craniotomy, and gross total resection of the tumor was achieved without adjuvant therapy., Outcomes: No clinical or neuroradiological evidence of recurrence or residual of the tumor was found 6 years and 2 months after initial surgery., Lessons: Cerebellar liponeurocytoma developing in supratentorial cerebral hemisphere was first reported in the present study. The radiological and histopathological features may be useful in differentiating this rare tumor from other tumors at similar locations. A change in the nomenclature of cerebellar liponeurocytomas should be considered in future World Health Organization (WHO) classifications., (Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Central neurocytomas are defined as neoplasms composed of round, uniform cells, with neural immunophenotypic profile and low proliferation index. They account for 0.5% of intracranial tumors. They usually occur near the foramen of Monro and can cause obstructive hydrocephaly. We conducted a retrospective data collection from records of 12 patients with central neurocytomas in the Anatomopathological Laboratory at the Mohammed VI University Hospital, Marrakech, between January 2006 and June 2015. This study aimed to report and describe the radiopathological features of this rare histologic type. The male/female sex-ratio was 1.4. The average age at diagnosis was 22.3 years. The revealing symptomatology was dominated by intracranial hypertension associated with decreased visual acuity and diplopia in all patients. Our study concerned about simple biopsy in one case, subtotal resection in seven cases and total resection in four cases. Histopathological examination showed tumor proliferation with endocrine architecture. Tumor cells are more often small and uniform. Mitotic index was low. Tumor proliferation was associated with fibrillary fundus and vascular network with three types of trees. Immunohistochemical examination was identical in all patients. It showed tumor cells positive for anti-synaptophysin antibodies, chromogranine and NSE. In all patients the radio-pathologic correlation suggested central neurocytoma (grade II - WHO 2016). This study highlights the anatomo-clinical, radiological and evolutionary features of these rare tumors.

We present a case of a rare neoplasm in a 77-year-old woman with previous oncological history, who developed a rapid onset of cerebellar symptoms. The neuroimaging detected a posterior fossa tumor suspected of meningioma which was completely resected soon after. Histologically the neoplasm had two components with different immunophenotype. One constituent was lobular, composed of monotonous mitotically active round cells with a predominant neuronal profile. The second, astrocytic component contained lipomatous cells intermixed with larger gemistocytic astrocytes. Fields of geographic necrosis as well as multifocal microvascular proliferation were observed. The Ki67 proliferation index was 12%. After two years of follow-up the patient remains free of symptoms and radiologic recurrence. The presented case of cerebellar liponeurocytoma is unusual in terms of its atypical histological features and prominent astrocytic component. The authors propose that the term 'lipomatous glioneuronal tumor' seems to be more appropriate for this type of lesion, considering its histologic spectrum and possible extracerebellar location.

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.

Aim: To better understand the clinical characteristics of central neurocytoma (CN), as well as to assess the optimum therapeutic schedule., Material and Methods: This was a retrospective study of 32 patients with CN who visited our department between January 2008 and January 2013. We analyzed the clinical and radiological presentations, tumor characteristics, surgical strategies, and the prognosis., Results: We performed operation guided by combined intraoperative magnetic resonance imaging (iMRI) and neuronavigation in 25 patients. The iMRI detected residual tumor in 9 cases, and further resection was performed in 5 cases. Total and nearly total tumor resection was achieved in 29 cases (91%). There was no significant difference between transcortical and transcallosal approaches in complications. Two cases (6%) with recurrence received respectively repeat salvage surgery and radiosurgery at 46 and 50 months after surgery. Thirty patients (94%) had excellent functional outcome (Karnofsky Performance Score ≥80) and 28 patients (88%) resumed their occupations., Conclusion: Our study demonstrates radical surgery with excellent neurological outcomes is the primary treatment of CN. The techniques of resection guided by combined iMRI and neuronavigation seems to enable a higher complete resection rate and reduce the morbidity rate during surgery. We suggest careful clinical observation after initial surgery, and repeat salvage surgery or radiosurgery for recurrent CN.

Central neurocytoma/extraventricular neurocytoma is a central nervous system (CNS) tumor composed of uniform round cells with neuronal differentiation. The typical lesions of central neurocytoma/extraventricular neurocytoma are at the interventricular foramen of the lateral ventricles (central neurocytoma) or brain parenchyma (extraventricular neurocytoma). Mature teratoma is a benign germ cell tumor commonly found in young women. Herein, we report a 24-year-old female with neurocytoma in a mature teratoma of the right ovary. The histological examinations showed mature epidermis, skin appendages, adipose and bone tissues in the tumor; microscopic foci of immature cartilage tissues were also found in some parts. In addition, massive solid sheets and uniform round tumor cells were found in the neuroectodermal tissues, with the formation of neuropil-like islands. Immunohistochemical examinations showed that the tumor cells were synaptophysin- and NeuN-positive but GFAP-negative. Based on these findings, the woman was diagnosed with neurocytoma arising from mature ovary teratoma, with microscopic foci of immature cartilage tissues. This is the fourth case report of neurocytoma outside the CNS to date.

We report a case of an intraventricular tumor with features of atypical central neurocytoma with a sarcomatous component in a 44-year-old woman who presented with headaches and vomiting. Magnetic resonance imaging revealed a 3.4-cm lobulated enhancing mass in the occipital horn of the left lateral ventricle, and the patient subsequently underwent a left occipital-parietal craniotomy for debulking. The tumor contained 2 cell populations: round cells with perinuclear halos in a fibrillary background, and spindle cells with oval nuclei arranged in interlacing fascicles with focal necrosis. The round cells had diffuse synaptophysin immunopositivity, while the spindle cells were diffusely immunopositive for vimentin and had intercellular reticulin. The mitotic activity (8 mitotic figures per 10 high-power fields) and the high Ki-67 proliferation index (15.0%) were consistent with atypical central neurocytoma with a sarcomatous component. Although different histologic variants have been described, this is the first reported case, to our knowledge, of central neurocytoma with spindle cell sarcomatous features.

Central neurocytoma is generally considered to be a benign tumor and the literature suggests that a cure may be attained by surgery ± adjuvant focal irradiation. However, there is a need for change in the therapeutic strategy for the subgroup of patients with aggressive central neurocytoma. An example case is presented and the literature on central neurocytoma cases with malignant features and dissemination via the cerebrospinal fluid is reviewed and the radiotherapeutic strategies available for central neurocytoma treatment is discussed. Nineteen cases including the present report with a malignant course and cerebrospinal fluid dissemination have been described to date, most of them involving an elevated MIB-1 labeling index. Our case exhibited atypical central neurocytoma with an initially elevated MIB-1 labeling index (25-30 %). The primary treatment included surgery and focal radiotherapy. Three years later the disease had disseminated throughout the craniospinal axis. A good tumor response and symptom relief were achieved with repeated radiation and temozolomide chemotherapy. Central neurocytoma with an initially high proliferation activity has a high tendency to spread via the cerebrospinal fluid. The chemo- and radiosensitivity of the tumor suggest a more aggressive adjuvant therapy approach. Cases with a potential for malignant transformation should be identified and treated appropriately, including irradiation of the entire neuroaxis and adjuvant chemotherapy may be considered.

Background: Central neurocytoma and oligodendroglioma are rare tumors of the central nervous system. However, diagnosis between these two types of tumors is challenging due to their many cytological and histological similarities. Death-associated protein kinase (DAPK) is a calcium/calmodulin-regulated serine/threonine protein kinase involved in many apoptosis pathways, and repressed expression of DAPK by promoter hypermethylation has been found in a variety of human cancers. The purpose of this study was to assess DAPK protein expression and promoter hypermethylation in central neurocytoma and oligodendroglioma., Method: Central neurocytoma and oligodendroglioma samples were obtained from age- and sex-matched patients. DAPK protein expression was performed using immunohistochemical assays in formalin-fixed, paraffin-embedded sections. DAPK promoter hypermethylation was carried out using bisulfite-modified genomic DNA in methylation-specific PCR followed by separation in agarose gels., Findings: A statistically significant difference (P = 0.021) in DAPK promoter hypermethylation between central neurocytoma (76.9%) and oligodendroglioma (20%) was observed. High levels of DAPK protein expression were generally found in oligodendroglioma (90%), compared with 38.5% in central neurocytoma (P = 0.054; not statistically significant). There was an inverse correlation between DAPK protein expression and DAPK promoter hypermethylation in the cohort of 23 patients (P = 0.002)., Conclusions: The results show that DAPK promoter hypermethylation and repressed expression of DAPK protein were more common in central neurocytoma than in oligodendroglioma. Thus, DAPK promoter hypermethylation could be useful for differential diagnosis between these two types of tumors, whereas DAPK protein expression might be less predictive. The role of DAPK promoter hypermethylation in the pathogenesis of central neurocytoma warrants further study.

A rare tumour, cerebellar liponeurocytoma, is classified into glioneuronal tumours under the 2000 World Health Organization (WHO) classification of tumours of the central nervous system. The current 2007 WHO classification, therefore, assigns grade II to the cerebellar liponeurocytoma. Tumours are predominantly localized in cerebellar hemispheres, and the second most common location is the vermis. To date, approximately 40 reported cases of cerebellar and 10 cases of supratentorial intraventricular liponeurocytoma have been reported. In this report, an unusual case of cerebellar liponeurocytoma was presented with extracerebellar location. In the future tumour classification, it should be considered that liponeurocytomas are not restricted only to the cerebellum, but they are located in supratentorial areas as well.

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.

Extraventricular neurocytoma is a rare entity, most frequently occurring in brain parenchyma outside the ventricular system. The purpose of this study was to characterize the MR imaging findings in a series of 9 patients with EVN verified by results of pathologic examination. All 9 EVNs were solitary and intracranially located. Eight lesions were well demarcated, and 3 showed intratumoral hemorrhage. The solid parts of 7 tumors were primarily isointense on T1-weighted images and heterogeneously enhanced on T1WI with contrast. Although cerebral EVNs can present a wide spectrum of appearances on MR, the imaging patterns appear to vary according to anatomic location and cellularity. Lesions in frontal or parietal lobes often present as well-demarcated large masses with cystic degeneration, hemorrhage, mild-to-moderate edema, and inhomogeneous enhancement. Moreover, the general isointensity of the solid parts of EVN on T1WI may be of some specificity.

Extraventricular neurocytoma is a rare neuroepithelial tumor. Its propensity to occur in cerebral hemisphere is much higher. EVN has a histological resemblance to central neurocytoma but radiologically, it is more complex. Ganglionic differentiation is more common in EVN and tends to have more of a cystic component. Calcification is frequent but hemorrhage is only an occasional finding. Although it has been reported to occur in various regions, the propensity to occur in cerebral hemisphere is much higher. Herein, we report two cases which presented as a mass in the right frontal lobe and right parietal lobe. MRI showed hypointesity on T1, hyperintesity on T2-weighted images with moderate enhancement after contast injection. In short extraventricular neurocytoma should be considered indifferential diagnosis of complex intracranial masses.

Cerebellar liponeurocytoma is a rare neoplasm with distinctive morphologic features. It typically involves the cerebellar hemispheres of middle-aged to older adults. The tumor is composed of a uniform population of neurocytic cells possessing round to oval nuclei and pale to clear cytoplasm. A variable degree of lipidization of the tumor cells is present, lending a resemblance to mature adipose tissue. Immunohistochemistry serves to confirm the neurocytic differentiation of the tumor cells. In the 2007 revision of the World Health Organization classification of central nervous system tumors, cerebellar liponeurocytoma was reclassified as a grade II neoplasm to reflect a higher recurrence rate than was previously appreciated.

Background: In humans, central neurocytomas are rare and typically benign intracranial tumors found within the lateral ventricles, although extraventricular variants have been reported. Intracranial central neurocytomas have not been previously recognized in domestic animals., Objectives: To describe the clinicopathologic features of canine intracranial central neurocytomas., Animals: Two dogs with spontaneous intracranial and intraventricular neoplasms., Results: Both dogs experienced seizures, rapid neurological deterioration, and death from tumor-associated complications within 5 days of the onset of clinical signs, and had neoplastic masses within the lateral ventricles. A brain MRI was performed in 1 dog, which revealed a T1-isointense, heterogeneously T2 and FLAIR hyperintense, and markedly and heterogeneously contrast-enhancing mass lesions within both lateral ventricles. Histologically, the neoplasms resembled oligodendrogliomas. The diagnosis of central neurocytoma was supported by documenting expression of multiple neuronal markers, including neuron-specific enolase, synaptophysin, neural-cell adhesion molecule, and neuronal nuclear antigen within the tumors, and ultrastructural evidence of neuronal differentiation of neoplastic cells., Conclusions and Clinical Importance: Central neurocytoma should be a differential diagnosis for dogs with intraventricular brain masses. Morphologic differentiation of central neurocytoma from other intraventricular neoplasms, such as ependymoma or oligdendroglioma, can be difficult, and definitive diagnosis often requires immunohistochemical or ultrastructural confirmation of the neural origin of the neoplasm., (Copyright © 2012 by the American College of Veterinary Internal Medicine.)

Extraventricular neurocytoma (EVN) in the spinal cord is extremely rare and only 15 cases have been reported in the English literature. Fourteen cases presented as an intramedullary lesion with spinal cord enlargement in cervico-thoracic segment and one case presented as an extramedullary lesion originating from cauda equina. Herein, we report an unusual spinal neurocytoma with exophytic growth from the thoracic spinal cord with cord compression mimicking meningioma. To our knowledge, this is the first case of exophytic spinal neurocytoma recorded in the English literature.

Extraventricular neurocytoma (EVN) is a rare neoplasm described in the 2007 World Health Organization classification of tumours of the nervous system. Due to the rarity of the tumour, there is limited literature available. The clinical characteristics, pathological features, biological behaviour and outcome of EVN remain unclear, and there are challenges regarding its diagnosis and management. The present case was a 75-year-old man who had been experiencing slow responses to stimuli for 1 month prior to hospital admission. A diagnosis of atypical EVN was made on the basis of pathology and immunohistochemistry results. Atypical pathological features included vascular proliferation, the presence of mitosis and a high MIB-1 (an antibody against Ki-67) labelling index. The disease recurred 7 months after the initial complete resection and radiation treatment, presenting with dural metastasis and codeletion of chromosomes 1p/19q. The present case history and treatment course are discussed with respect to the literature.

A seventeen-year-old female patient was admitted with sudden-onset of headache and vomiting. Brain magnetic resonance imaging demonstrated a heterogeneously enhancing tumour in the left lateral ventricle. The tumour was removed and confirmed as a central neurocytoma (CN). For the residual tumour in the left lateral ventricle, gamma knife stereotactic radiosurgery was done at fifteen months after the initial surgery. Tumour recurred in the 4th ventricle at 5 yr after initial surgery. The tumour was removed and proved as a CN. In vitro primary culture was done with both tumours obtained from the left lateral ventricle and the 4th ventricle, respectively. Nestin, a neuronal stem cell marker was expressed in reverse Transcriptase-Polymerase Chain Reaction of both tumors. Both tumours showed different morphology and phenotypes of neuron and glia depending on the culture condition. When cultured in insulin, transferrin selenium and fibronectin media with basic fibroblast growth factors, tumour cells showed neuronal morphology and phenotypes. When cultured in the Dulbeco's Modified Essential Media with 20% fetal bovine serum, tumors cells showed glial morphology and phenotypes. It is suggested that CN has the characteristics of neuronal stem cells and potential to differentiate into mature neuron and glial cells depending on the environmental cue.

A 21-year-old man presented with a hemorrhagic central neurocytoma manifesting as acute onset of disturbance of consciousness and right hemiparesis. Computed tomography (CT) demonstrated a tumor in the left lateral ventricle during the course of evaluation for mental alteration 12 days before onset, but the tumor was left untreated because the patient refused to visit a neurosurgical institution. CT on admission revealed a large mass lesion located in the body of the lateral ventricle associated with massive intratumoral and intraventricular hemorrhage. He underwent emergent surgery for evacuation of the tumor with hematoma, and his neurological symptoms gradually recovered after surgery. The present case highlights the possibility of rapid deterioration of symptoms by massive hemorrhage from central neurocytoma. Surgical intervention should thoroughly be considered, if intratumoral hemorrhage is present, as hemorrhage from the central neurocytoma may lead to serious neurological complications.

Background: Central neurocytoma is a rare primary brain tumour, mostly localised in the lateral ventricles in relation to the foramen of Monro., Objectives: To report a case of a rare central neurocytoma with a complete loss of Synaptophysin expression and provide the differential diagnosis., Methods and Results: We describe a case of a 34-year old man with a headache, unsteady gait and dim vision. MRI demonstrated a tumorous expansion localised in both lateral ventricles. The patient underwent a subtotal resection. Histology showed a picture consistent with central neurocytoma, but tumour was completely negative for Synaptophysin. We describe our approach in such a diagnostically difficult case., Conclusions: In the rare case of Synaptophysin-negative central neurocytoma, its neuronal differentiation should be substantiated by electron-microscopic examination. Unfortunately in the routine work, biopsy samples are usually fixed in formalin fixative which does not preserve ultrastructure well. In such situations, an accurate diagnosis is disputable and based on careful assessment of the histological features, exclusion of tumours with similar morphology and detailed correlation with MRI pictures (Fig. 4, Ref. 6). Full Text (Free, PDF) www.bmj.sk.

The long-term outcome of gamma knife radiosurgery (GKS) for central neurocytomas remains unclear. In the present study, we retrospectively reviewed the medical records of 7 patients with 8 central neurocytomas who underwent GKS between March 1997 and April 2007. They were 3 men and 4 women age ranging 9 to 53 years old (mean 32.5 years old). The tumor volume at the time of GKS was 0.34-6.10 cm(3) (mean 3.86 cm(3)). All patients had undergone 1 to 3 incomplete surgical resections (mean 1.75) before GKS, the surgical specimen being evaluated histologically and immunohistochemically. The follow-up period after GKS was 15 to 136 months (mean 63.6 months). The tumors were treated with a marginal dose of 12-18 Gy (mean 13.9 Gy). Only one of the seven patients died of tumor recurrence and intracranial hemorrhage 40 months after GKS. The other tumors remained progression-free. The control rate of the tumor growth was 7/8. Although histological malignant transformation is rare, the postoperative course of this tumor is not always good, showing tumor progression, intracranial hemorrhage, or craniospinal dissemination. Therefore, we recommend GKS for residual or recurrent tumors especially at early detection before tumor progression.

Aim: Evaluation of a peak at 3.55 ppm in a long echo time (TE) recognized as glycine (Gly) in the WHO grade II gliomas and central neurocytomas by means of 1H MRS., Material and Methods: Retrospective analysis of 19 patients with histopathologically confirmed WHO grade II glioma and 2 patients with central neurocytoma was conducted. 1H MRS (TE = 135 ms and TE = 144 ms) was performed with 1.5 T and 3.0 T scanners. Gly/Cr, Gly/Cho and Gly/NAA ratios were compared between the analysed groups. Additional analysis of a brain of 61 healthy volunteers was conducted., Results: Glycine was distinguished in 12 out of 19 (63%) WHO grade II gliomas. Among those 12 WHO grade II gliomas only in 26% of a spectra Gly was recognized. In both central neurocytomas Gly was distinguished and in 43% of the spectra Gly was recognized. The ratio of Gly/Cr in central neurocytomas was higher than in WHO grade II gliomas (mean(CNC) 0.62 ± 0.18 vs. mean(WHO II) 0.37 ± 0.10; p < 0.001) but the ratio of Gly/Cho was lower (mean(CNC) 0.18 ± 0.04 vs. mean(WHO II) 0.24 ± 0.07; p < 0.001). There was no difference between analysed groups in terms of Gly/NAA ratio (mean(CNC) 0.36 ± 0.09 vs. mean(WHO II) 0.36 ± 0.14; p = NS). Only in 0.3% of the spectra of normal brain Gly was distinguished., Conclusions: Glycine is found in WHO II grade gliomas as well as in central neurocytomas, but only in a part of a tumor volume. It is necessary to perform 1H MRS of the whole tumor volume to confirm/exclude the presence of glycine. Glycine in a normal brain can not be identified by means of conventional 1H MRS performed by means of 1.5 T or 3.0 T scanners.

This article presents a brief review of the 2007 World Health Organization classification of tumours of the central nervous system.

Co-deletion of chromosome arms 1p and 19q, characteristic of oligodendroglial tumors, was recently found to be mediated by t(1;19)(q10;p10). To evaluate the prevalence of 1p19q co-deletion and t(1;19) in extraventricular neurocytomas (EVN), we studied tumors from 23 patients, including 13 females and 10 males (median age at diagnosis 34 years, range 2-76 years). Fluorescence in situ hybridization (FISH) studies were performed with probes targeting 1p36/1q25 and 19q13/19p13 to assess for 1p19q co-deletion, as well as chromosome 1 alpha-satellite and 19p12 to detect t(1;19)(q10;p10). FISH was successful in 21 (91%) cases and demonstrated 1p19q co-deletion in five cases (24%) or isolated 1p loss in two cases (10%). Evidence for t(1;19) was found in four (of five) cases with 1p19q co-deletion. Three tumors with 1p19q loss and t(1;19) demonstrated atypical histologic features, compared with one (of 17) tumors without 1p19q co-deletion (P = 0.01, Fisher exact test). In addition, tumors with t(1;19) showed increased mitotic activity compared with tumors without t(1;19) (P = 0.045; Wilcoxon rank sum test). The four patients with t(1;19) developed tumor recurrence (n = 3), or expired (n = 2) 3.5 to 5.5 years after first resection. These results suggest that 1p19q loss and t(1;19) occur in a subset of EVN, and may be associated with aggressive histology in these tumors.

A case of ganglioneurocytoma of the spinal cord in a 51-year-old man is reported. Patient presented with a progressively worsening back pain and hyposthenia of lower limbs. Magnetic resonance imaging of the spinal cord revealed an intradural lesion in the T10-11 spinal segments, hyperintense on T1-weighted sequences. Complete resection was achieved. The patient did not show evidence of recurrence 12 months after surgery. On histology, the lesion was composed of round to oval cells with fine granular, slightly eosinophilic to clear cytoplasm suggesting a neurocytic differentiation. Some ganglion cells were observed. Neither significant cytologic atypia nor mitoses were present. The neoplastic cells were strongly positive with synaptophysin and negative with glial fibrillary acid protein. Neurocytomas are uncommon tumors typically arising within the lateral ventricles near the foramen of Monro. Extraventricular neurocytomas have been reported at various sites with rare examples in spinal cord. In the present paper, a case of ganglioneurocytoma of the spinal cord is reported with review of literature and discussion of differences compared to neurocytomas of other sites.