Central neurocytoma: a clinicopathological and neuroradiological study

Gamma Knife radiosurgery for the treatment of central neurocytoma: a single-institution experience of 25 patients

Central neurocytomas (CNs) are extremely rare tumors that account for 0.1-0.5% of all intracranial neoplasms. Recently, Gamma Knife radiosurgery (GKRS) has become a treatment option in patients with CN. We aimed to evaluate the efficacy and safety of GKRS in 25 CN patients and review the results along with relevant literature. GKRS patient database was searched, and 25 patients who underwent GKRS for CN between 2009 and 2018, were evaluated retrospectively. The study cohort included 15 female and ten male patients with a median age of 32 years (range, 5-60). The most common presenting symptom was headache (88%). The neurological examination was unremarkable in all patients, except for one patient with decreased vision. Twenty patients (80%) had a history of surgical resection. Most of the tumors (92%) were located in the ventricles, and the median tumor volume was 4.8 cm³ (range, 0.8-28.1). The median marginal dose was 14 Gy (range, 12-15) to a median isodose of 50% (range, 40-50). Following a median follow-up of 80 months (range, 36-138), local tumor control was achieved in 100% of patients. Distant recurrence was observed in one patient (4%). No adverse radiation effect was observed. Regarding non-specific post-GKRS symptoms, one patient experienced a prolonged headache, and one epileptic patient experienced a brief partial seizure. In our patient cohort, GKRS yielded favorable local tumor control (100%) during a median follow-up of 6.6 years. Our series demonstrates that GKRS is an effective and safe treatment option for patients with primary or residual CNs.

Role of susceptibility-weighted imaging and intratumoral susceptibility signals in grading and differentiating pediatric brain tumors at 1.5 T: a preliminary study

PURPOSE

Susceptibility-weighted imaging (SWI) is useful for glioma grading and discriminating between brain tumor categories in adults, but its diagnostic value for pediatric brain tumors is unclear. Here we evaluated the usefulness of SWI for pediatric tumor grading and differentiation by assessing intratumoral susceptibility signal intensity (ITSS).

METHODS

We retrospectively enrolled 96 children with histopathologically diagnosed brain tumors, who underwent routine brain MRI exam with SWI (1.5 T scanner). Each tumor was assigned an ITSS score by a radiology resident and an experienced neuroradiologist, and subsequently by consensus. Statistical analyses were performed to differentiate between low-grade (LG) and high-grade (HG) tumors, histological categories, and tumor locations. Inter-reader agreement was assessed using Cohen's kappa (κ).

RESULTS

The interobserver agreement was 0.844 (0.953 between first reader and consensus, and 0.890 between second reader and consensus). Among all tumors, we found a statistically significant difference between LG and HG for ITSS scores of 0 and 2 (p = 0.002). This correlation was weaker among astrocytomas alone, and became significant when considering only off-midline astrocytomas (p = 0.05). Scores of 0 and 2 were a strong discriminating factor (p = 0.001) for astrocytomas (score 0) and for embryonal, choroid plexus, germ-cell, pineal, and ependymoma tumors (score 2). No medulloblastoma showed a score of 0.

CONCLUSIONS

Our preliminary ITTS results in pediatric brain tumors somewhat differed from those obtained in adult populations. These findings highlight the potential valuable role of ITSS for tumor grading and discriminating between some tumor categories in the pediatric population.

Clinical outcome and prognostic factors for central neurocytoma, a study of 14 cases

Background: Since they’re rare, the intraventricular neoplasms “central neurocytoma” best management got diverse, and mystifying.

Aim of the work: to assess outcome for patients with central neurocytoma and value of specific factors like tumor size, surgical resection extent, atypia, and concomitant other modality of treatments by radiotherapy in their survival.

Patients & methods: 14 patients (8 males, 6 females) were managed surgically between 2012 and 2016. They were assessed clinically, radiologically and their outcome in relation to selected factors.

Results: Median age at diagnosis was 28.3 years in average (range 16–58). Median follow-up was 32.2 months.we lost 2 cases to follow-up in post-operative period. Six patients had recurrent of neurocytoma tumours.Five patients (35.7 %) obtained gross total resections (GTR) while 9 patients (64.2 %) had subtotal resections (STR). Two STR patients (14.2 %) received dose of radiation post operatively that significantly enhanced overall PFS (p =0.047). our series data propose that radiation therapy following (STR) usually increase (PFS). Two patients proved to have atypical neurocytoma by pathological reports died at 2.3 and 10.2 months after the microsurgical procedures. MIB-1 tagging index higher than 4 % is an indicator for poor outcome. We used Kaplan–Meier beside Cox proportional hazards methods in determining the Progression-free survival (PFS) in our study.

Conclusion: the extent of surgical resection may improve the neurological condition but not the survival, Atypia was the most important factor determine the recurrence & survival while radiotherapy improve the survival quietly.

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.

Clinical, radiological, pathological and prognostic aspects of intraventricular oligodendroglioma: comparison with central neurocytoma

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.

Central Versus Extraventricular Neurocytoma in Children: A Clinicopathologic Comparison and Review of the Literature

BACKGROUND

Central neurocytomas (CN) are rare pediatric CNS tumors most often with a benign clinical course. Occasionally, these tumors occur outside the ventricles and are called extraventricular neurocytomas (EVN). We present a retrospective institutional analysis of children with neurocytoma with prolonged follow-up.

PROCEDURE

Twelve patients were diagnosed with neurocytoma at our institution between 1993 and 2004.

RESULTS

Six patients were male and the median age at diagnosis was 12 years (1.5 to 16 y). Seven patients had CN and 5 had EVN. Presenting symptoms included headaches (67%), vomiting (50%), nausea (33%), seizures (33%), and mental status changes (25%). Obstructive hydrocephalus was present at diagnosis in 42% of the cases. Younger age and seizures were more common in patients with EVN. Gross total resection (GTR) was achieved in 42% (5/12) of the patients. Patients with GTR received no adjuvant therapy upfront; 1 patient subsequently had recurrence with leptomeningeal disease. Patients with subtotal resection received additional treatment: 1 underwent reoperation (GTR), 2 patients received focal radiation, 2 patients received adjuvant chemotherapy, and 2 patients received craniospinal irradiation followed by chemotherapy. The 20-year overall survival for this cohort was 83% with event free survival of 56%. Overall survival for CNs was 100%, versus 40% for EVN. Event free survival for CNs was 57% and 53% for the EVNs. An MIB-1 fraction >2% was associated with worse prognosis.

CONCLUSIONS

Neurocytomas are rare brain tumors in children usually cured with GTR. Adjuvant focal radiation therapy and/or chemotherapy may improve disease control in cases with subtotal resection, but case-by-case analysis should be done. EVNs might be associated with worse outcome due to a higher proliferative index.

Estimation of proliferative potentiality of central neurocytoma: correlational analysis of minimum ADC and maximum SUV with MIB-1 labeling index

BACKGROUND

Central neurocytoma was initially believed to be benign tumor type, although atypical cases with more aggressive behavior have been reported. Preoperative estimation for proliferating activity of central neurocytoma is one of the most important considerations for determining tumor management.

PURPOSE

To investigate predictive values of image characteristics and quantitative measurements of minimum apparent diffusion coefficient (ADCmin) and maximum standardized uptake value (SUVmax) for proliferative activity of central neurocytoma measured by MIB-1 labeling index (LI).

MATERIAL AND METHODS

Twelve cases of central neurocytoma including one recurrence from January 2001 to December 2011 were included. Preoperative scans were conducted in 11, nine, and five patients for computed tomography (CT), diffusion-weighted imaging (DWI), and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET), respectively, and ADCmin and SUVmax of the tumors were measured. Image characteristics were investigated using CT, T2-weighted (T2W) imaging and contrast-enhanced T1-weighted (T1W) imaging, and their differences were examined using the Fisher's exact test between cases with MIB-1 LI below and above 2%, which is recognized as typical and atypical central neurocytoma, respectively. Correlational analysis was conducted for ADCmin and SUVmax with MIB-1 LI. A P value <0.05 was considered significant.

RESULTS

Morphological appearances had large variety, and there was no significant correlation with MIB-1 LI except a tendency that strong enhancement was observed in central neurocytomas with higher MIB-1 LI (P = 0.061). High linearity with MIB-1 LI was observed in ADCmin and SUVmax (r = -0.91 and 0.74, respectively), but only ADCmin was statistically significant (P = 0.0006).

CONCLUSION

Central neurocytoma had a wide variety of image appearance, and assessment of proliferative potential was considered difficult only by morphological aspects. ADCmin was recognized as a potential marker for differentiation of atypical central neurocytomas from the typical ones.

Diffusion weighted MR imaging and proton MR spectroscopy findings of central neurocytoma with pathological correlation

PURPOSE

Three cases of histopathologically confirmed central neurocytoma (CN) are presented, emphasizing diagnostic imaging issues: conventional magnetic resonance imaging with Proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI) findings of CN.

MATERIALS AND METHODS

Patients age ranged from 17 to 32 years, Imaging include a CT scan and MR examination with DWI and proton MRS on a 1.5-T system. DWI and subsequent apparent diffusion coefficient (ADC) were obtained in all. Single voxel MRS was performed prior to surgery using a point resolved spectroscopy sequence (PRESS) with short 35 ms and long echotime (TE) 144 ms, associated with a two-dimensional chemical Shift Imaging (2D-CSI) with 144 ms TE (one case). Histopathological examination included immunostaining with synaptophysin.

RESULTS

With the long TE, a variable amount of glycine with markedly increased choline, very small to almost complete loss of N-acetylaspartate and creatine, and inverted triplet of alanine-lactate were observed in all three patients. Increased glutamate and glutamine complex (Glx) was also observed in all with short TE. DWI demonstrated variable low ADC which appeared well correlated with the tumor signal intensity and cell density: the most homogeneous and highly dense cellular tumor with increased nucleus to cytoplasm ratio demonstrated the lower ADC. Histological pattern was typical in two cases and demonstrated an oligodendroglioma-like pattern in one case. Positivity for synaptophysin confirmed the neuronal origin in all.

CONCLUSION

The demonstration within an intraventricular tumor of both glycine and alanine on MRS along with high choline, bulky Glx and restricted diffusion appear diagnostic of CN.

Central neurocytoma: long-term outcomes of multimodal treatments and management strategies based on 30 years' experience in a single institute

BACKGROUND

A thorough investigation of the long-term outcomes of central neurocytoma (CN) after different treatments is required to establish optimal management strategies.

OBJECTIVE

We retrospectively reviewed the long-term clinical outcomes of patients with CN according to various treatments and suggest treatment strategies based on 30 years of experience in a single institution.

METHODS

Fifty-eight consecutive patients with CN were treated at our institution between 1982 and 2008. Patient demographics, overall survival, local control rates according to multimodal treatments, and functional outcomes were evaluated. The mean clinical and radiological follow-up periods were 119 months (range, 18-304 months) and 98 months (range, 13-245 months), respectively.

RESULTS

The initial treatment modality was classified into 4 subgroups: operation only (34 patients), operation followed by radiation therapy (7 patients) or radiosurgery (7 patients), and radiosurgery alone (10 patients). The actuarial overall survival was 91% at 5 years and 88% at 10 years. The actuarial overall survival and local tumor control rate did not differ significantly according to the various treatments and the initial extent of the surgical resection. However, functional outcomes, such as the postoperative seizure outcome at the last follow-up, differed according to the surgical approach.

CONCLUSION

The long-term clinical outcomes of CN after multimodal treatment seem to be excellent. Our study suggests that treatment strategies for CN should focus on the patient's quality of life, as well as on tumor control, because of the benign nature of CN.

Clinical and imaging features of central neurocytomas

To describe the clinical and imaging characteristics of patients with central neurocytoma (CN), we reviewed data on 27 patients who had histologically confirmed CN and were treated in our institution between 1999 and 2010. Neuro-imaging findings on CT scan (n=18) and MRI (n=25) were retrospectively evaluated. There were 15 males and 12 females with a mean age of 29 years (range, 11-46 years). The most frequent presentations included headache (n=21) and vomiting (n=6). Tumor sites included bilateral lateral ventricles (n=10), right lateral ventricle (n=7), left lateral ventricle (n=7) and fourth ventricle (n=3). On MRI, the T1-weighted signal was hypointense in 12 patients and isointense in 13, and the T2-weighted signal was isointense in 8 patients and hyperintense in 15. CT scans/MRI revealed a cystic component in 18 patients. Tumors showed a mild to marked enhancement in 26 patients. Flow voids from tumor vessels on MRI were present in 14 patients, and calcification was noted in six of 18 patients with CT scans. All lateral ventricle tumors were resected through a transcortical or transcallosal approach. Gross total resection was achieved in 19 patients, near total in two and subtotal in six. One patient died of cerebral infarction in the perioperative period. At the last follow up, there were three known clinical recurrences in this series. However, no recurrence was noted in 17 patients who underwent gross total resection with no adjuvant therapy.

Contrast-enhanced MR imaging in neuroimaging

MR imaging without and with gadolinium-based contrast agents (GBCAs) is an important imaging tool for defining normal anatomy and characteristics of lesions. GBCAs have been used in contrast-enhanced MR imaging in defining and characterizing lesions of the central nervous system for more than 20 years. The combination of unenhanced and GBCA-enhanced MR imaging is the clinical gold standard for the noninvasive detection and delineation of most intracranial and spinal lesions. MR imaging has a high predictive value that rules out neoplasm and most inflammatory and demyelinating processes of the central nervous system.

[Central neurocytomas of the lateral ventricle. A series of 35 cases with review of the literature]

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.

Gamma knife radiosurgery for cranial neurocytomas

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.

[Central neurocytoma: Study of 32 cases and review of the literature]

Central neurocytoma is a rare benign neoplasm of the central nervous system. The intraventricular location close to the Monro foramina and the attachment to the septum pellucidum are characteristic for the diagnosis. However, atypical appearances may be encountered and confused with other neoplasms. The authors report the radiological findings of 32 surgically treated and pathologically confirmed neurocytomas.

Dysembryoplastic neuroepithelial tumor located in pericallosal and intraventricular area in a child. Case report

Dysembryoplastic neuroepithelial tumors (DNETs) are frequently seen in children and young adults with intractable epilepsy, and are typically located in the temporal cortex. Extracortical location of DNET is a very rare occurrence. The authors report on a child with a unique extracortical location of DNET with an extensive involvement to the supracallosal cistern and callosum, septum pellucidum, and lateral ventricle ependyma. The authors discuss the radiological and pathological characteristics of the lesion and reiterate the difficulty in differentiating the histological characteristics of central neurocytoma and DNET in extracortical locations and its significance for further management planning.

Imaging findings of extraventricular neurocytoma: report of 3 cases and review of the literature

Extraventricular neurocytoma (EVN) is rare entity with similar biologic behavior and histopathologic characteristics to neurocytomas that occur in the lateral ventricles, according to the 2007 World Health Organization classification. We report the cases of 3 patients with extraventricular neurocytoma, which presented as large tumors in the left frontal and parietal lobes and in the sellar region. MR imaging showed cystic degeneration, calcification and/or hemorrhage, intense enhancement, and perilesional edema. EVN should be considered in the differential diagnosis for large, heterogeneous, enhancing brain tumors that occur in young people.

Central neurocytoma: proton MR spectroscopy and diffusion weighted MR imaging findings

PURPOSE

To present proton magnetic resonance spectroscopy and diffusion-weighted imaging (DWI) findings of central neurocytoma (CN).

METHODS AND MATERIALS

Imaging findings of seven patients with the histopathological diagnosis of CN (five male and two female; age range, 21-28 years of age) were evaluated retrospectively. In addition to conventional magnetic resonance imaging features, we also assessed the metabolite ratios and tumor normalized apparent diffusion coefficient (NADC), which was calculated by dividing the tumor apparent diffusion coefficient (ADC) values by normal ADC. Approval from our institutional review board was obtained for this review.

RESULTS

The tumor choline/creatine ratios were 5.17+/-2.38, while N-acetyl aspartate/choline and N-acetyl aspartate/creatine ratios were 0.33+/-0.15 and 1.84+/-1.38, respectively. On DWI, tumors had heterogeneous hyperintense appearances when compared with the contralateral parietal lobe white matter and tumor NADC values were 0.63+/-0.05.

CONCLUSION

Significantly increased choline/creatine and decreased N-acetyl aspartate/choline ratios with lower NADC values in CN resemble high-grade gliomas and complicate the diagnosis. Familiarity its physiologic features would help to presurgical diagnosis of ventricular and exraventricular CNs.

Alanine peak in central neurocytomas on proton MR spectroscopy

INTRODUCTION

We present three consecutive patients with central neurocytoma in whom proton MRS demonstrated the presence of alanine.

MATERIALS AND METHODS

Three patients in the age range 24 to 30 years underwent MRI and proton MRS using a 1.5-T system. MRS was performed with the multivoxel PRESS sequence. All three patients underwent surgery and the diagnosis of central neurocytoma was established by histopathological examination and immunostaining.

RESULTS

With an echo time of 135 ms glycine, high choline, small NAA and alanine were observed in all three patients.

CONCLUSION

Alanine may be observed in central neurocytomas as it is in meningiomas. Other spectral peaks such as those for glycine and NAA should help to identify this tumor correctly.

Investigating the effect of exchange and multicomponentT1 relaxation on the short repetition time spoiled steady-state signal and the DESPOT1T1 quantification method

PURPOSE

To examine the spoiled steady-state (spoiled gradient-recalled echo sequence [SPGR]) signal arising from two-compartment systems and the role of experimental parameters, in particular TR for resolving signal from each compartment.

MATERIALS AND METHODS

Using Bloch-McConnell simulations, we examined the SPGR signal from two-component systems in which T(1) is much greater than the mean residence time (tau(m)) of proton spins in each component. Specifically, we examined the role of TR on the ability to resolve each components signal, as well as the influence of experimental parameters on derived DESPOT1 T(1) values.

RESULTS

Results revealed that when TR < or = 0.01 tau(m), the measured SPGR signal may be modeled as a summation of signal from each species using a no-exchange approximation. Additionally, under this short TR condition, the driven equilibrium single pulse observation of T(1) (DESPOT1) mapping approach provides T(1) values preferentially biased toward the short or long T(1) species, depending on the choice of flip angles.

CONCLUSION

The ability to model the SPGR signal using a no-exchange approximation may permit the quantification multicomponent T(1) relaxation in vivo. Additionally, the ability to preferentially weight the DESPOT1 T(1) value toward the short or long T(1) may provide a useful window into these components.

Pontine Atypical Neurocytoma: Case Report

OBJECTIVE AND IMPORTANCE:

Neurocytomas are typically located within the supratentorial ventricular system. Extraventricular neurocytomas are very rare, and this is only the second reported case of a pontine neurocytoma. We discuss the clinical presentation, histology, and treatment of these rare tumors.

CLINICAL PRESENTATION:

A 58-year-old man presented with a 4-month history of headache and unilateral facial and distal extremity paresthesia. Magnetic resonance imaging (MRI) scans demonstrated a 2.6 × 2.2-cm ring-enhancing cystic mass in the right pons.

INTERVENTION:

MRI-guided stereotactic biopsy yielded a diagnosis of atypical neurocytoma. Because of the location and malignant histological features of the tumor, the patient was initially treated with external beam radiation therapy. Several months later, MRI scans demonstrated tumor progression. The patient then underwent three rounds of temozolomide chemotherapy, during and after which his symptoms worsened. Aggressive subtotal resection of the tumor was achieved via a right suboccipital craniectomy.

CONCLUSION:

Twenty-eight months postoperatively, the patient is symptom free, and MRI scans demonstrate no evidence of residual or recurrent tumor.

Central neurocytoma: clinical, pathological and neuroradiological findings

AIM

To evaluate the clinical, pathological and neuroradiological features of intraventricular central neurocytoma in six patients.

MATERIALS AND METHODS

Six patients were imaged using non-enhanced and contrast-enhanced magnetic resonance imaging (MRI); three of them were also examined using non-enhanced computed tomography (CT). Two radiologists read the images retrospectively. The imaging data were studied with regard to location, size, margin, signal intensity, enhancement characteristics and presence of calcifications. Clinical data (i.e. presenting signs and symptoms, physical findings and medical histories) were collected and histopathological and immunohistochemical studies were performed by two pathologists.

RESULTS

All lesions were located in the lateral ventricles. Three tumors were confined to the left side, one to the right side and two cases involved both lateral ventricles. The growth of central neurocytoma was of close spatial relation to the septum pellucidum. On MRI, most of the cases showed a heterogeneous hypointensity on T1-weighted images and hyperintensity on T2-weighted images or FLAIR with a well-defined margin. The presence of cystic components, necroses and calcifications caused these internal heterogeneities. After intravenous administration of gadolinium (Gd-DTPA) all tumours showed a heterogeneous enhancement. CT provided additional information by distinguishing intratumoural calcifications in all three evaluated cases. Immunohistochemical analysis showed positive synaptophysin staining in all cases and positive neuron-specific enolase staining in four cases. In three cases a small proportion of the tumour cells could be labelled with antibodies to glial fibrillary acid protein (GFAP).

CONCLUSION

Central neurocytoma should be considered when the following conditions occur: young patients with lesions in the lateral ventricle, which contain calcifications and show some enhancement. This is especially applicable for tumours involving both lateral ventricles with symmetrical growth around the centre of septum pellucidum or for unilateral ventricular tumors with a wide base attachment to the septum pellucidum.

Central neurocytoma: report of two cases

INTRODUCTION: Central neurocytomas are rare neuroectodermal tumors believed to arise from the subependymal matrix of the lateral ventricles. CASE REPORTS: A 26-year-old woman and a 33-year-old man each had a large, heterogeneous, contrast enhancing mass in the lateral ventricles at the foramen of Monro causing bilateral hydrocephalus. The woman died after surgery, but the man is asymptomatic after three years. HISTOPATHOLOGY: Both tumors were composed of isomorphic rounded cells positive for synaptophysin, chromogranin and NSE, while some reacted for GFAP, vimentin and S-100 protein. Electron microscopy revealed neuropil-like tissue between cells, but synapses were rare.