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Background: The management of lateral ventricle tumors requires a balance between maximizing safe resection and preserving neurological function., Method: The authors present a successful case of a left lateral ventricular central neurocytoma resection. The trans-superior frontal sulcus approach was employed, providing a safe corridor while minimizing damage to the surrounding neuroanatomy. The use of an endoscope further facilitated the procedure, enabling the confirmation of complete tumor removal and the preservation of deep venous drainage and periventricular structures., Conclusion: This case highlights the utility of the trans-sulcal approach and the benefits of endoscopic assistance in the management of lateral ventricle tumors., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Introduction: Central Neurocytoma (CN) is a rare, WHO grade 2 brain tumor that predominantly affects young adults. Gross total resection (GTR) is often curative for CNs, but the optimal treatment paradigm including incorporation of RT, following subtotal resection (STR) and for scarcer pediatric cases has yet to be established., Methods: Patients between 2001 and 2021 with a pathologic diagnosis of CN were reviewed. Demographic, treatment, and tumor characteristics were recorded. Recurrence free survival (RFS) and overall survival (OS) were calculated according to the Kaplan Meier-method. Post-RT tumor volumetric regression analysis was performed., Results: Seventeen adults (≥ 18 years old) and 5 children (< 18 years old) met the criteria for data analysis (n = 22). With a median follow-up of 6.9 years, there was no tumor-related mortality. Patients who received STR and/or had atypical tumors (using a cut-off of Ki-67 > 4%) experienced decreased RFS compared to those who received GTR and/or were without atypical tumors. RFS at 5 years for typical CNs was 67% compared to 22% for atypical CNs. Every pediatric tumor was atypical and 3/5 recurred within 5 years. Salvage RT following tumor recurrence led to no further recurrences within the timeframe of continued follow-up; volumetric analysis for 3 recurrent tumors revealed an approximately 80% reduction in tumor size., Conclusion: We provide encouraging evidence that CNs treated with GTR or with RT after tumor recurrence demonstrate good long-term tumor control., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

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., (© 2022. The Author(s).)

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.

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

In 2007, extraventricular neurocytoma was classified as a separate entity among glioneuronal tumors. However, extraventricular neurocytoma is not fully understood and may be misdiagnosed. Here, we describe the clinical and pathological features, prognoses, and treatments of 13 extraventricular neurocytoma cases, and compare their immunophenotypes with those of oligodendroglioma, diffuse astrocytoma, and ependymoma. Six typical and 7 atypical cases comprised the 13 extraventricular neurocytoma cases. Histological features included oligodendroglioma-like perinuclear halo, neuropil-like matrix, ganglion or ganglioid cells, perivascular pseudorosettes, vessel hyalinization, calcifications, and myxoid degeneration. Atypical histological features included increased mitotic figures, focal necrosis, endothelial cell proliferation, and/or a Ki-67 index of >2%. All lesions expressed synaptophysin and microtubule-associated protein-2, which distinguished them from other similar tumors. Two patients with atypical extraventricular neurocytoma had tumor recurrence, one of whom had cerebrospinal fluid dissemination, suggesting that atypical histological features might represent adverse prognostic factors. In conclusion, the present study identified morphological and immunohistochemical features that would aid the differential diagnosis of extraventricular neurocytoma. In addition, radiotherapy with subtotal resection could be considered an effective treatment for extraventricular neurocytoma, but because a pediatric patient died of intracranial hemorrhage during radiotherapy, radiotherapy-related side effects should be considered, especially when treating children. Additional cases with long-term follow-up are needed to develop optimal management protocols for extraventricular neurocytoma.

Similar histology and clinical behavior of both intraventricular central neurocytomas (CNs) and extraventricular neurocytomas (EVNs) may argue against the idea that EVNs were the distinct entity to distinguish from CNs in the 2007 World Health Organization classification. To explore respective characteristics and compare similarities and differences in CNs and EVNs, relevant clinical, radiological, operative and pathological data of 49 patients (35 CNs and 14 EVNs) in the Department of Neurosurgery at our hospital from 2005 to 2012 was reviewed and some comparisons between CNs and EVNs were conducted. The factors affecting posttreatment recurrence of CNs and EVNs were assessed by Cox regression analysis. In comparison, CNs showed a more typical clinical manifestation, and radiological and histopathological features, while EVNs demonstrated more malignant biological behavior, with higher MIB-1 index (p = 0.006), higher rate of atypia (p = 0.042), higher recurrence rate (p = 0.028), and shorter time to recurrence (p = 0.049). Subtotal resection was associated with higher rates of recurrence in both CNs (hazard ratio [HR] 6.16, p = 0.046) and EVNs (HR 5.26, p = 0.045), and atypia was also associated with a higher recurrence rate in CNs (HR 5.03, p = 0.042). CNs were thus easier to diagnose than EVNs, with typical clinical, radiological, and histopathological features, while the latter were more likely to show malignant biological behavior associated with atypia and recurrence. Total surgical resection is the optimal treatment choice for both CNs and EVNs, and patients with either CN or EVN with typical and/or totally resected lesions showed favorable clinical outcomes.

Aims and Objective: Extra ventricular neurocytoms (EVN) are a rare parenchymal brain tumour distinct from central neurocytomas. This review attempts to analyze a series of seven cases of EVN from a single institute against the background of available literature., Method: Retrospective analysis of the clinical manifestation, pathological features, imaging findings, microsurgical treatment effectiveness and progression free survival of seven cases of EVN operated between 2000-2012., Results: The study group included five females and two males in the age group 7-65 years (mean 30.71 yrs). The distribution of the lesion was as follows Lobar 4, Cerebellum 1, Pineal 1, spinal 1. The duration of clinical symptoms ranged from three months to seven years and the presentation was site and size specific. Cystic Changes (71 %), perilesional oedema (57 %) and heterogeneous contrast enhancement (85.7 %), and calcification (42 %) were a few distinct imaging characteristics. Increased perfusion correlated with atypical histology in two patients. Surgical resection remains the main management strategy for longer outcome and patients with STR + RT and GTR had comparable follow-up. Extremes of age and atypical histological features were adverse prognostic factors., Conclusion: EVN are rare tumors with either glial or neuronal differentiation or a potential for atypical changes. Both, GTR and STR combined with RT, offer reasonably good outcome with overall comparable survival. The available literature of EVN is limited, larger series with long term follow-ups are needed to dictate the management protocol. The role of adjuvant therapy is still debatable and needs further validation.

Background: Extraventricular neurocytomas (EVNs) are rare neuronal tumors included as neoplasms in the 2007 World Health Organization (WHO) classification of tumors of the CNS. Although a few case reports describing EVNs have been published, a systematic analysis of MR imaging findings of EVN has not been reported. Furthermore, imaging findings of IDH1 mutation-negative EVNs have not yet been reported. The aim of our study is to describe the MR imaging findings of IDH1 mutation-negative EVNs., Methods: MR images of ten patients with pathologically confirmed IDH1 mutation-negative EVNs were retrospectively reviewed. Conventional MR imaging of ten EVNs were reviewed with emphasis on the location, signal intensities, patterns, and grades of enhancement as well as the presence/grade of peritumoral edema, intratumoral cyst, hemorrhage, and calcification. The study also reviewed the results of DWI (b = 1,000 s/mm(2), n = 7)., Results: Seven EVN cases were located in the cerebral hemisphere, and the remaining cases were in the cerebellum and thalamus. Of those in the cerebral hemisphere, five were cortically based tumors. The tumors showed no or mild peritumoral edema. Eight tumors were enhanced on the postcontrast T1WIs. An intratumoral cyst, hemorrhage, and calcification were detected in four, one, and two cases, respectively. On DWI, only one case showed a lower ADC value than the brain parenchyma., Conclusion: EVNs are usually cortically based infiltrative hemispheric tumors with contrast enhancement, higher ADC value, and sometimes small cystic component, but hardly show peritumoral edema or intratumoral hemorrhage. The differential diagnosis of these findings includes low-grade glioneuronal tumors and low-grade gliomas.

Objective: To analyse the clinical characteristics of intraventricular central neurocytomas and gain a better understanding of the surgical management and treatment strategies., Methods: A total of 92 cases of intraventricular central neurocytomas with initial treatment using surgical resection were studied retrospectively., Results: Among 48 male and 44 female patients, 65 underwent gross total resection and 27 underwent subtotal resection. Transcortical or transcallosal approaches were performed, and there was no significant difference between the two approaches in terms of effects and complications. Tumours with calcification or adhesion had a significant lower gross total resection rate. Three patients died after surgery. During follow-up, 55 patients underwent postoperative radiotherapy and four patients had a recurrence of the tumour., Conclusion: Central neurocytomas mostly occur in the lateral ventricle system near the foramen of Monro. Therefore, total resection is the best treatment. Two surgical approaches are possible as treatment. Calcifications or adhesions affect the gross total resection of the tumour. Radiation therapy or radiosurgery therapy can be chosen as a salvage treatment in case of recurrence.

Background: Central neurocytomas (CN) are rare intraventricular tumors with benign clinical behavior that typically affect young adults. Although a favorable prognosis is generally expected after adequate management, there is no general consensus on the standard of therapy. We evaluated the efficacy and safety of radical surgery for the management of CN., Methods: Between 1996 and 2010, 12 patients with CN (eight males and four females; range, 18 to 62 years; mean age, 28.5 years) were surgically treated in our institution. The initial goal of therapy was complete resection through a frontal transcortical approach, and repeat surgery was done in cases of residual or recurrent disease. The mean follow-up period was 51.2 months (range, 14-149 months)., Results: Complete resection was achieved in all patients either with primary (nine patients, 75 %) or second-look surgery (three patients, 25 %). No mortalities occurred and there were four surgery-related complications (two events of transient hemiparesis, one transient aphasia, and onepostoperative subdural hygroma). All patients were alive with normal activities of daily living at the last follow-up. Two patients (16.6 %) experienced a single recurrence at 26 and 66 months, one of whom underwent redo-surgery., Conclusion: For the management of CN, complete resection is feasible, effective, and safe. Repeat surgery may be a viable option in cases of residual or recurrent disease and the use of radiotherapy can be avoided in this young population.

Gamma-knife surgery may be an effective alternative for treatment of central neurocytomas owing to its relative safety compared with conventional radiotherapy. In this paper we present results of gamma-knife treatment (GKS) of residual or recurrent neurocytomas. Twenty-two patients (14 female, 8 male) with recurrent or residual neurocytomas who underwent GKS were included. Diagnosis was based on histological findings. The proliferative potential of the tumors was examined by immunostaining with MIB-1 antibody, which is specific for detection of Ki-67 antigen. Tumor volume was determined by using post-gadolinium magnetic resonance images. After GKS treatment, MR imaging was scheduled at three-month intervals in the first year, at six months intervals in the second year, and yearly thereafter. Histopathological diagnoses were: 18 cases of central neurocytomas, two liponeurocytomas, one cerebral neurocytoma and one cerebellar neurocytoma. The MIB1 labeling index (LI) varied from 0 to 5.7%. Marked reduction in tumor volume was seen in 15 patients. In six patients, the tumor volume remained unchanged, and progression was observed for one patient. No complications because of GKS were noted. Shrinking effect on tumor volume increased with increasing duration of follow-up. On the other hand, high MIB labeling index did not seem to have an effect on tumor response to GKS treatment. Findings of this study suggest that GKS is an effective and safe treatment alternative for residual or recurrent neurocytomas. However, its effectiveness should be confirmed with larger studies.

Liponeurocytoma is not exclusive to the cerebellar or fourth ventricular location. Since its inclusion in the central nervous system tumor classification in 2000, six cases with similar radiological, histomorphological and immunohistochemical features have also been described in the lateral ventricles. In the present study, we report clinical, radiological and pathological findings of three supratentorial and one cerebellar liponeurocytoma from our records, evaluated with an extensive panel of immunohistochemistry, and review published cases in the literature. The immunohistochemical pattern of supratentorial and infratentorial liponeurocytomas are almost identical, which indicates that these tumors are homologous.

Coincidence of parenchymal primary brain tumors of different histogenesis is extremely rare. To the best of our knowledge, the present case of simultaneous appearance of a central neurocytoma and multiple glioblastomas is the first to be reported. Multiple intraaxial brain neoplasms were disclosed in a 39-year-old man and were surgically resected. Histological diagnosis of the tumor located in the right lateral ventricle was central neurocytoma whereas two tumors of the left temporal lobe were glioblastomas. The latter were located in close proximity to the subarachnoid space, had atypical radiological appearance, and were slightly positive for synaptophysin and neurofilament protein. It can be speculated that both malignant neoplasms were, in fact, dedifferentiated central neurocytoma, which developed from distant tumor deposits. This case seems to be in agreement with the hypothesis that central neurocytoma arises from the progenitor cells with potential for both neuronal and glial differentiation. Better understanding of histogenesis of this tumor is definitely needed.

The spinal cord is a very rare location for extra-ventricular neurocytomas. Composed of small round cells with neuronal differentiation, neurocytoma has a particularly favourable prognosis. Long disease-free intervals have been observed in patients who received sub-total removal and radiotherapy. A careful intra-operative frozen section examination is helpful in avoiding excessive surgical tissue disturbance and to identify the best treatment option. To date, eight cases of neurocytoma of the spinal cord have been described. We report three more patients; one with very long survival, and review the published literature for this condition.

The authors report the long-term outcome of conventional radiation therapy (RT) in six cases of central neurocytoma (CN). Between 1985 and 1992, six patients were treated with RT for residual tumors or for prevention of recurrence after surgery. The median follow-up period of radiological and clinical status were 171 (range: 128-229) and 202 months (range: 165-227), respectively. Tumors disappeared in three and reduced in three patients at the last follow-up. One-mortality case due to radiation necrosis and one radiation-induced malignancy occurred. White matter degeneration and cortical atrophy were noticed with slow progression of performance deterioration in two patients. Conventional RT seemed to effectively control residual CN after surgery. However, more sophisticated radiation techniques should be applied to minimize the late sequela.

Differentiating oligodendroglioma from extraventricular neurocytoma by conventional light microscopy alone can present a diagnostic challenge. We report pathologic findings of an unusual spinal cord tumor from a 33-year-old male patient which showed hybrid features of oligodendroglioma and extraventricular neurocytoma. Magnetic resonance imaging (MRI) showed an enhancing intramedullary mass in the cervicothoracic region (C7 through T6). Histologic examination revealed a clear cell neoplasm containing ganglion-like cells and calcifications, prompting the differential diagnosis of oligodendroglioma and extraventricular neurocytoma. The immunohistochemical analysis disclosed neural differentiation of the neoplastic cells with strong synaptophysin and neurofilament staining consistent with extraventricular neurocytoma, as well as strong S-100 and glial fibrillary acidic protein (GFAP) expression. Molecular studies with fluorescent in situ hybridization (FISH) revealed chromosome 1p/(partial) 19q deletions, a finding commonly observed in oligodendroglioma. The proliferation index (using antibody MIB1) of the tumor was approximately 30%. The morphologic findings and these results strengthen the hypothesis that these tumors may share a common progenitor cell, which has also been observed by others. Because there are differences in patient management and long-term prognosis, it is important to attempt to distinguish between oligodendroglioma and neurocytoma. This unusual case and similar rare reported cases support the need to reclassify tumors showing pathologic features common to both neurocytoma and oligodendroglioma as a unique entity, while the effort continues to identify the cell of origin.

Objective and Importance: Central neurocytoma is recognized as a indolent intraventricular tumor arising from the ependyma around the foramen of Monro and anterior part of the lateral ventricles, and well demarcated from the brain parenchyma. Surgical removal can be curative without postoperative therapy. However, malignant central neurocytoma refractory to even aggressive treatment is known., Clinical Presentation: We report two cases of extraventricular central neurocytomas with significant vascular proliferation, mitoses, and MIB-1 labeling index of more than 10%., Intervention: Subtotal removal for the one patient and open biopsy for other followed by radiotherapy with chemotherapy were performed. However, the disease progressed and dissemination occurred. Both patients subsequently died 23 and 18 month after the histological diagnosis was established., Conclusion: Extraventricular central neurocytoma may present with frequent vascular proliferation and high MIB-1 labeling index. Even if they lack malignant histological findings like frequent mitosis and/or necrosis, the prognosis for such patients is very poor.

Neurocytomas gained importance since 1995, which is reflected by the increasing number of reports on this entity. This study was performed to determine the best available treatment for typical and atypical neurocytomas (MIB-1 labeling index >3%, atypical histology) in various age groups ( 18 years). The data of all neurocytoma patients reported since 1982, when this entity were reviewed for age, gender, extent of resection, MIB-1 labeling index, histology, radiotherapy, and outcome of therapy. Patients were treated with complete resection alone (CTR), CTR plus radiotherapy (CTR + RT), incomplete resection alone (ITR), or ITR plus radiotherapy (ITR + RT). If the reported data were incomplete, the authors were contacted for additional data. Follow up had to be at least 12 months. Data were complete in 438 patients (73 children, 365 adults). Three hundred and fifty-one patients had typical, 87 atypical lesions. Typical lesions were associated with better local control and survival than atypical lesions (P < 0.001). CTR was superior to ITR (P < 0.001). After CTR, outcome was not significantly improved by RT. After ITR, RT improved survival in typical lesions (P = 0.03) and atypical lesions (P = 0.05), not in children (P = 0.16). Local control was improved in all groups (P < 0.001, children P = 0.01). Doses >54 Gy appeared beneficial after ITR of atypical lesions. In children, 50 Gy were comparable.CTR does not require post-operative RT. Following ITR, RT improves outcome. Of 50-54 Gy appear sufficient for typical lesions, 50 Gy for children. Atypical lesions require 56-60 Gy.

We report a case of a 25 year old man presenting with acute headache, vomiting and nuchal rigidity. Computed Tomography (CT) scan and MRI without contrast showed a right ventricular hemorrhage surrounding a mass lesion. The tumor and hematoma were completely removed by neurosurgical transcortical-transventricular approach. Anatomopathological analysis revealed a central neurocytoma. Central neurocytoma seldom present with hemorrhage. We review 16 cases of neurocytoma with hemorrhage. It is important to recognize central neurocytoma as a cause of intraventricular hemorrhage, especially in adolescents and young adults. Outcome is often favorable when the tumor is completely removed. In some patients the clinical course is more aggressive and additional treatment such as radiotherapy, radiosurgery or chemotherapy is needed.

Most central neurocytomas (CN) and spinal neurocytomas (SN) have a bland well-differentiated histologic picture and uneventful clinical course. However, rare examples showing histologic atypia, recurrence and even CSF dissemination have been reported. Herein we report a case of recurrent spinal neurocytoma in a 24-year-old male who presented with a 2-month history of weakness and numbness of the left upper and lower limbs, and was previously operated at the same site 10 months ago. MRI revealed a contrast enhancing intramedullary mass involving C5-T1 region. Radiologic and operative impression at both surgeries was that of a glioma, possibly anaplastic. Histologic and immunohistochemical features in both resections were those of an atypical neurocytoma. The tumor showed rare mitoses, focal mild vascular proliferation in both specimens, and necrosis in the initial specimen. MIB1 labeling indices were 9 and 10%, respectively. Based on the analysis of this case and limited data from the literature, it is hypothesized that SN shows a histopathologic picture, immunoprofile and biologic behavior very similar to CN. However, the presence of histologic atypia and increased MIB1 index in SN appear to more closely correlate with tumor recurrence and a worse overall outcome, in part due to their location in the critical region of cervical spinal cord. Therefore, we hypothesize that SN with atypia requires a close clinical follow up. As in CN, radiation therapy is perhaps best reserved for atypical, progressive and recurrent SN.

For investigation of histogenesis of central neurocytomas (CNs), subependymoma (SEs), subependymal giant cell astrocytomas (SEGAs), we studied expression of various neuronal and glial biomarkers by immunohistochemical (IHC) study and reverse transcriptase-polymerase chain reaction (RT-PCR). The materials for IHC were paraffin section of seven CNs, three SEs, and eight SEGAs and those for RT-PCR were frozen tissues of seven CNs, three SEs, and five SEGAs. Control group was five ependymomas (EPs) and four pilocytic astrocytomas (PAs). The neuronal biomarkers included nestin, chromogranin A (chrA), synaptophysin (SNP), neuronal cell adhesion molecule (NCAM), neuron specific enolase (NSE), neuronal nuclear antigen (NeuN), neurofilament (NF) and the glial marker was GFAP. CNs expressed all neuronal markers except NF (0%), SNP (100%), NCAM (100%), NSE (100%), NeuN (100%), nestin (29%) and chrA (43%), but GFAP expression was found only in one case (14%). SEGA coexpressed several neuronal markers and a glial marker; NeuN (100%), NSE (88%), NCAM (63%), nestin (100%), SNP (weakly and focally, 100%), and GFAP (100%), however, other neuronal markers including chrA, SNP and NF were all negative. SE expressed nonspecific neuronal markers (NCAM (100%) and NSE (100%)) which showed weak intensity and a GFAP (100%), but not nestin. Among control cases of EPs and PAs, no one case expressed neuronal markers except nonspecific neuronal marker of NCAM, but robustly expressed GFAP. RT-PCR product of nestin was expressed in 29% of CNs (2/7cases), 60% of SEGAs (3/5 cases), 100% of SEs (3/3 cases), 80% of EPs (4/5 cases), and 25% of PAs (1/4 cases). Conclusively, coexpression of neuronal and glial markers and expression of nestin in CNs, SEGAs and SEs suggested the origin of these tumor cells might be the stem cells being able to differentiate into both neuronal and glial phenotypes. But CNs might be originated from rather neuronally committed stem cells and SEs from rather glially committed stem cells.

Neurocytomas are rare neuronal tumours, and are defined as tumours comprising cells with neuronal differentiation; they commonly arise in the ventricles. We report a case of a cerebral neurocytoma in a young man who presented with hemiparesis. The tumour was a radiologically a well-circumscribed large cyst with solid mass; the histopathology showed a well-differentiated lesion comprising uniform, round cells with perinuclear halos in a neuropil background, and immunohistochemically positive for neuronal markers (synaptophysin, neuron-specific enolase and neurofilaments). We suggest that cerebral neurocytomas should be considered among the uncommon causes of a large intra-axial cystic mass with a solid component in young adults.

Central neurocytomas are rare intraventricular neoplasms of the central nervous system, compromising 0.25-0.5% of brain tumors. The diagnosis and management of these tumors remains controversial since most clinical series are small. Typically, patients with central neurocytomas have a favorable prognosis, but in some cases the clinical course is more aggressive. Although histological features of anaplasia do not predict biologic behavior, proliferation markers including MIB-1 might be more useful in predicting relapse. The most important therapeutic modality is surgery, and a safe maximal resection confers the best long-term outcome. In cases of a subtotal resection,'standard external beam radiation can be added or radiation can be delayed until tumor progression occurs. Smaller residual tumor volumes or recurrences can be treated with more conformal radiation or focused radiosurgery. Re-operation for recurrence should be considered if the procedure can be safely performed. Chemotherapy may be useful for recurrent central neurocytomas that cannot be resected and have been radiated, although long-term responses have not been reported for chemotherapy. Overall, this paper reviews the findings of the larger studies and highlights some of the important case reports that contribute to the current management of central neurocytomas.

Objectives: The purpose of this report was to review our experience with stereotactic radiosurgery in the management of patients with residual neurocytomas after initial surgery., Methods: Between October 1996 and December 2001, four patients with central neurocytoma were treated by surgery and subsequently underwent linear accelerator (LINAC) radiosurgery., Results: Two of the patients were cured, one exhibited a significant reduction in tumour size and the fourth remains stable. All four patients are alive and well., Conclusions: In cases of small residual tumours or recurrences radiosurgery allows open surgery to be avoided and is a safe and potentially effective approach.

Central neurocytomas are typically benign tumors that have high local control rates after gross total resection. Radiotherapy for residual or recurrent central neurocytomas is controversial. We report a 30-year-old male with a central neurocytoma in the lateral ventricle. The tumor was subtotally resected through a transcallosal approach, and subsequently treated with gamma knife radiosurgery. The tumor had shrunken markedly by 2 months after radiosurgery and remained unchanged during the one year follow-up period. Gamma knife radiosurgery may be an option for effective treatment of patients with residual or recurrent central neurocytomas.

Central neurocytoma was first described by Hassoun et al. in 1982. The tumor is a rare benign tumor of the central nervous system, usually located in the lateral ventricles. Most reported cases are histologically and clinically benign. Several cases with recurrence have been described. Including the case presented here, only seven cases with craniospinal dissemination have been reported. None of the previous cases with dissemination had histological atypia but most did have a high MIB-1 labeling index (MIB-1 LI). Our patient had a high MIB-1 LI (4.6%) and dissemination was found to have advanced through the anterior horns of the lateral ventricles and to the spinal cord at the T4 level. The patient underwent partial resection of the tumor with follow-up radiation treatments for the residual tumor and dissemination. After the radiation, the size of the tumor decreased. The report of this casewill be helpful in the treatment of disseminated central neurocytoma.

Central neurocytoma is an unusual tumour that arises in the supratentorial ventricular system of young adults. Similar lesions, termed simply neurocytoma, have been described at a variety of locations outside the ventricular system. Here, we report the case of a 50-year-old man who presented with pain and a rapidly progressive myelopathy due to a neurocytoma of the upper thoracic spinal cord. The literature on spinal neurocytoma and its relation to central neurocytoma are discussed.

Background: Cerebellar liponeurocytoma has only recently been recognized as a distinct clinicopathological entity. Although the few cases described in literature support the relatively benign nature of this lesion, optimum treatment strategy and long term behaviour still have to be defined., Clinical Presentation: This 61-year-old man came under our observation with unspecific signs of intracranial hypertension and a symptomathology revealing a probable posterior fossa lesion. Imaging studies showed a cerebellar mass lesion with prevalent adipose content., Intervention: Gross total tumour removal was performed. The pathological examination revealed a lesion composed of medulloblastoma-like cells with prominent areas of lipidisation. A review of literature has been made in an attempt to investigate on recurrence patterns, importance of the extent of removal and the usefulness of radiotherapy., Conclusion: The few cases reported in literature so far seem to confirm the relatively benign nature of cerebellar liponeurocytoma. No radiotherapy was given in our case and the reasons for this decision are reported.

Background: The proliferative activity and metabolic features of three central neurocytomas were investigated using the findings of thallium-201 single photon emission computed tomography ((201)Tl-SPECT) and proton magnetic resonance spectroscopy ((1)H-MRS), and the MIB-1 labeling index (MIB-1 LI)., Method: The early and delayed (201)Tl indices were calculated as the ratio of tumour to normal brain tissue uptake by (201)Tl-SPECT. In vivo single-voxel (1)H-MRS was performed with echo time of 272 msec to evaluate the metabolites including choline (Cho), N-acetyl aspartate (NAA) and creatine/phosphocreatine (Cre). An external standard reference was used to semiquantitate each metabolite. MIB-1 LI was determined in the surgical specimens., Findings: The MIB-1 LI was 0.5%, 1.2%, and 7.5% in an atypical central neurocytoma without intraventricular extension. Significant (201)Tl uptake was observed on delayed images in all three central neurocytomas. (1)H-MRS showed the high Cho peaks relative to the NAA and Cre peak. The signal at 3.55 ppm, which may be due to inositol or glycine, was observed in one central neurocytoma., Interpretation: Both (201)Tl-SPECT and (1)H-MRS did not reflect the proliferative potential of central neurocytomas.

Central neurocytoma (CN) is described as a rare intra-ventricular benign neuronal tumor of the brain. Two primary tumors first diagnosed as malignant and extra-ventricular neurocytomas are reported here. Histologically, the tumor of the first patient, a forty-one-year-old man, consisted of monotonous cells with round nuclei, but no fibrillar background. The second tumor, in a nineteen-year-old girl, showed areas of moderately pleomorphic round cells, with numerous rosettes and ganglion cell differentiation, in an abundant fibrillary network. Both presented calcifications. Mitoses were more frequent in recurrences and spinal locations than in the primaries. All tumors stained strongly for synaptophysin, and GFAP was partly positive in the first case only. Patients received post-surgical radiotherapy and were still alive eight and six years, respectively, after initial surgery. The interpretation of atypical cases, such as ours is not easy: the diagnoses finally retained were oligodendroglioma in the first case and ganglioneuroblastoma in the second case. Furthermore, neurocytomas atypical either by their unusual topographical or histological presentation or by their poor prognosis, have been frequently entitled in this way on synaptophysin positivity. So, we were prompted to reassess the entity of CN, seventeen years after the first description, to re-appreciate the reality of anatomo-clinical variants and to discuss the value of synaptophysin positivity in these tumors. In conclusion, it seems preferable to individualize true classical CN, which has a favorable outcome, from so-called extra-ventricular, atypical and anaplastic, clinically malignant neurocytomas for which complementary treatment is required.

Central neurocytoma is a rare benign tumor of the central nervous system occuring in young adults and typically located in the ventricles. The tumor is composed of small round cells with neuronal differentiation and has a favourable prognosis. We report two cases of giant central neurocytomas with a triventricular extension in two young women. The first case concerned a 26 years old righthanded woman in whom an intraventricular mass was discovered, after a car accident with head trauma. Skull radiography showed an enlargment of the sella turcica. A CT scan performed in order to examine the pituitary gland revealed a voluminous and heterogenous intraventricular tumor with calcification. The second case concerned a 26 years old righthanded woman, presenting with a 4 Glasgow Coma Scale Score preceded by an acute onset of headache with projectile vomiting. A CT scan performed in emergency revealed a voluminous intraventricular mass with significant hydrocephalus. We review the different pathological and topographical patterns of previously published neurocytomas and discuss surgical management, effectiveness of radiation therapy and biological behavior.

We report a case of central neurocytoma treated, after an initial partial resection, by chemotherapy, comprising etoposide, ifosfamide and carboplatin. A response was obtained and further treatment was given with surgery and radiotherapy. There have been no previous reports of response to chemotherapy in this relatively rare tumour.

Central neurocytoma is considered to be a benign intracranial neoplasm, but little is known about the biological behavior of this type of tumor. Proliferative activity of central neurocytoma was measured in 10 cases using MIB-1 staining for Ki-67 antigen. The MIB-1 staining value varied from < 0.1% to 5.6%, to indicating that some of these tumors have proliferative potential similar to that of anaplastic astrocytoma or malignant meningioma. The bromodeoxyuridine labeling index (BUdR LI, BrdU LI) was measured in 2 cases and the results correlated well with those of the MIB-1 analysis. Tumor volume doubling time (Td) measured in one case was 358 days which is similar to that of malignant meningioma. In one case, the MIB-1 value taken before and after 58 Gy of radiation treatment decreased markedly from 5.6% to 0.2%. The other 9 cases were also treated by radiation therapy (50-60 Gy) and no tumor recurrence was observed during follow-up periods ranging from 23 to 160 months. Another two patients with partially removed and 3 with subtotally removed tumors showing relatively high MIB-1 values might also have benefited from radiation therapy.

The central neurocytoma is a recently recognized benign intraventricular tumour of young adults. The authors report a unique case of a panventricular neurocytoma with extension to the interpeduncular and prepontique cisterns which developed in a 35-year-old woman with a 7-year history of headaches and amenorrhea. They review the different pathological and topographical patterns of previously published neurocytomas and discuss the histogenesis of this rare tumour.

Two cases of central neurocytoma are presented. This is a rare CNS tumour affecting, predominantly, young individuals. There is enough evidence in the literature now to distinguish this entity clinically, radiologically and histologically. Much less is known about the management of patients with this tumour, because most of the reports are in pathological literature. Using our two cases and reviewing the available literature, we are endeavouring to shed light on the clinical aspects and management of central neurocytoma. In particular, we attempted to evaluate the role of surgical excision and radiation therapy in the management of this tumour.