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Background: Infratentorial multinodular lesions resembling multinodular and vacuolating neuronal tumor of the cerebrum (MVNT) have been indicated in literature with 2 different names reflecting alternative perspectives: multinodular and vacuolating posterior fossa lesions of unknown significance (MV-PLUS), suggesting that these lesions may belong to a new entity, and MVNT of the brain, assuming that they actually correspond to infratentorial MVNT. Because of the limited number of cases reported and the absence of histopathologic data, it is unclear which denomination should be used., Cases Description: Two patients, a 41-year-old man (case 1) suffering headache and a 44-year-old man (case 2) with vertigo, underwent magnetic resonance imaging (MRI) examination. MRI showed, in both cases, multinodular lesions involving the vermis, broadly extending to the superior part of the right cerebellar hemisphere in case 1, and involving the superior paravermian part of the left cerebellar hemisphere in case 2. The follow-up period was 3 years in case 1 and 14 years in case 2., Conclusions: Infratentorial lesions show nodules with cystic or cyst-like signal intensity on MRI, a feature infrequently reported in supratentorial MVNT, and may involve the cortex. No variations were noted during a prolonged follow-up supporting the benign behavior of these lesions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Although the epileptogenic location of dysembryoplastic neuroepithelial tumors (DNTs) is controversial, it has recently been thought to be located within cortical dysplasia (CD) due to its frequent association with CD. Among the 84 resection surgeries for intractable epilepsy performed in our institution between January 2003 and April 2010, three patients had epileptogenic DNTs. In two cases, chronic subdural electrocorticography (ECoG) was performed, and the ictal onset zone was revealed to be in the cortex around the DNT. The ictal onset zone was resected along with the DNT, and good seizure outcome was achieved. Although histological examination of the ictal onset zone revealed mild gliosis, coexistence of CD was not noted. In the third case, the DNT was located in the left lateral temporal lobe and the intraoperative ECoG revealed frequent paroxysmal activity in the medial temporal lobe. Resection of the lateral temporal lobe involving the tumor did not result in good seizure control. The optimal surgical treatment of DNT is controversial. Some authors consider lesionectomy to be sufficient for good seizure control, whereas others advocate that additional resection of the epileptogenic zone beside the tumor improves outcome. Because the epileptogenic location of DNT varies among cases, it is important to identify its location by preoperative multimodal examinations, including chronic subdural ECoG recordings.

Dysembryoplastic neuroepithelial tumors are rare, surgically curable, neuronal-glial neoplasms affecting young patients with intractable epilepsy. Its recognition is needed to avoid unnecessary adjuvant therapy. The authors reviewed the records of 15 patients with dysembryoplastic neuroepithelial tumors who underwent epilepsy surgery using intraoperative electrocorticography monitoring, including 8 males and 7 females (mean age, 15.8 years). Neuroimaging showed a predominantly intracortical location, the presence of septations, a triangular pattern of distribution, a lack of contrast enhancement, and an absence of peritumoral edema. Eleven cases were classified as complex type, 3 as simple type, and 1 as "nonspecific" type. Associated cortical dysplasia was found in 5 cases and leptomeningeal involvement in 1 case. Its immunophenotype suggested a pluripotential neuroepithelial origin. The mean follow-up was 37.5 months; 2 patients had tumor recurrence. Although they are generally benign neoplasms, recurrences sometimes occur. Complete resection of the tumor with the epileptogenic zone is important for a favorable outcome., (© The Author(s) 2013.)

Dysembryoplastic neuroepithelial tumors (DNETs) have traditionally been thought of as lesions with a benign clinical course that generally do not undergo malignant transformation. However, cases are emerging of DNETs that progress to more malignant forms. We present a case of malignant transformation, and we compile and review all previously published cases to identify common characteristics that may confer a higher risk for malignant transformation. A PubMed search was performed of all English-language case reports of DNET transformations to malignant cancers. The demographic, clinical, and histologic features of these patients are compiled and analyzed. A separate case report with histologic descriptions is also presented. A total of 10 case reports of DNET malignant transformation were found. The majority of cases involved complex-type DNETs. A higher proportion of extratemporal lesions were observed. Almost all cases involved subtotal resection. Risk factors for malignant progression of DNET lesions include complex-type histologic features, extratemporal location, and subtotal resection. Malignant dedifferentiation of astrocytic or oligodendrocytic cells within the glial nodule of complex DNETs may be the source of these transformations. There are no radiographic features that differentiate DNETs that are at higher risk for transformation.

Purpose: Dysembryoplastic neuroepithelial tumors (DNTs) provide a unique model for studying the effects of seizures on cognitive development. Epilepsy and antiepileptic medications are prominent features in the lives and schooling of people who develop seizures in childhood. People with an adult onset share the same underlying brain pathology, but their childhood development is unaffected by seizures. Therefore, DNTs provide a model to examine the specific influence of seizures and their treatment on cognitive development, over and above the effects of the underlying pathology in epilepsy., Methods: We examined the neuropsychological characteristics of 56 adults with DNT and medically intractable epilepsy (mean age 32.7 years). Twenty-two adults (39%) had an age of onset of epilepsy before the age of 12 years (childhood-onset group). Scores on tests of intelligence (Verbal IQ and Performance IQ), reading, working memory, verbal learning, verbal recall, visual learning, and expressive and receptive language ability were analyzed., Key Findings: There were no significant localization effects (right vs. left vs. extratemporal) on any of the neuropsychological test scores. In the group as a whole, the neuropsychological test scores were significantly lower than healthy, age-matched controls on measures of Verbal IQ (p < 0.01), naming p < 0.01, verbal learning (p < 0.01), and working memory (p < 0.05). The childhood-onset group had significantly lower scores on the measures of Verbal IQ (p < 0.01), Performance IQ (p < 0.05), reading (p < 0.05), naming (p = 0.05), and verbal retention (p < 0.05) than those with an onset of seizures at the age of 12 or older., Significance: The traditional pattern of lateralized memory deficits seen in people with hippocampal sclerosis may not be present in people with temporal lobe epilepsy associated with a DNT. The presence of seizures and their treatment in early childhood may adversely influence the development of these core cognitive abilities, resulting in patterns of cognitive deficits that remain apparent in adulthood., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

In this work we analysed, by immunohistochemistry, a series of brain tumors to detect the levels and cellular distribution of Hsp60 and Hsp70. We found that Hsp60 levels were significantly higher than those of Hsp70 in neuroepithelial tumors, while levels of both molecules were not significantly different from each other in meningeal neoplasms. In particular, Hsp60 immunopositivity was present mainly at the cytoplasmic level, while Hsp70 immunopositivity was found both in the cytoplasm and in the nucleus of tumor cells. The levels of these molecules in healthy control cells were always very low. Finally, Hsp60 and Hsp70 levels did not correlate with the different types (WHO grade) of neoplasm. Our results are partially in agreement with previous studies and suggest that Hsp60 is not increased by a passive phenomenon (e.g., due to the stress caused by the peritumor environment on cancer cells) but may be actively implicated in tumor progression, e.g. inhibiting tumor cell death or antitumor immune system response, as already postulated in vitro. We also briefly discuss the most recent publications on the extramitochondrial localization of Hsp60 in tumor cells and its role in tumor progression.

We retrospectively analyzed 15 years experience of awake surgeries for neuroepithelial tumors in Tohoku University. Awake surgeries mostly for language mapping were performed for 42 of 681 newly diagnosed cases (6.2%) and 59 of 985 surgeries including for recurrence (6.0%). When the same histologies and locations as cases resected under awake condition are selected from the parent population treated by radical resection, awake surgeries were most frequently performed for 14 of 55 newly diagnosed cases (25.5%) and 14 of 62 surgeries (22.6%) with grade II gliomas. In the results, 8 of 59 surgeries (13.6%) could not achieve complete language monitoring until the final stage of tumor resection, considered as failed awake surgery. Gross total resection was accomplished in 20 of 42 newly diagnosed cases (47.6%) and 32 of 59 surgeries (54.2%). Mortality rate was 0%. Late severe deficits were observed in 2 of 42 newly diagnosed cases (4.8%) and 3 of 59 surgeries (5.1%). Negative language mapping cases did not suffer severe deficits in both early and late stages. In contrast, high incidence of severe deficits, 3 as early and 2 as late of 8 cases, were identified with failed awake surgery. The overall survival of patients treated by awake surgery compared favorably with those treated without stimulation mapping and with stimulation mapping under general anesthesia. Awake surgery may contribute to improve the outcome of gliomas near eloquent areas by maximizing the tumor resection and minimizing the surgical morbidity.

Based on intracranial-video electroencephalography (EEG), histopathological features, and postoperative seizure outcome, we elucidated the epileptogenicity in patients with dysembryoplastic neuroepithelial tumor (DNT). Five patients (P1-P5) pathologically diagnosed with DNT underwent intracranial-video EEG to identify the ictal onset zone and irritative zone. We evaluated the correlations of ictal onset zone and irritative zone with the magnetic resonance imaging-visible lesion (MRI-lesion) and their histopathological features. Intracranial-video EEG located the ictal onset zone adjacent to the MRI-lesion margin in four patients with complex/simple forms of DNT subcategory, and on the MRI-lesion in P3 with a nonspecific DNT form. The irritative zone extended to surrounding regions of the ictal onset zone in all patients. Histopathologically, MRI-lesions were characterized by specific glioneuronal elements, whereas the ictal onset zone and irritative zone were represented with dysplastic cortex accompanying oligodendroglia-like cells in four (P1, P2, P4, and P5) of five patients. Cortical dysplasia was identified with typical histopathologic features in the irritative zone remote from the MRI-lesion in P5. P3, with a nonspecific form, indicated prominent component of dysplastic cortex with oligodendroglia-like cells scattered in the MRI-lesion. Lesionectomy of MRI-lesion with additional cortical resections (including the ictal onset zone and irritative zone) yielded postoperative seizure freedom (Engel Class I) in P3, P4, and P5, while P1 and P2 (with only lesionectomy) experienced postoperative residual seizure (Class II and III in each patient). Our results suggest the intrinsic epileptogenicity of DNT. The topographical correlation indicated that the dysplastic cortex accompanying oligodendroglia-like cells was more epileptogenic than the specific glioneuronal elements itself. Meticulous intracranial-video EEG analysis delineating the MRI nonvisible ictal onset zone and the irritative zone may yield better seizure outcome.

An algorithm was suggested for identifying highly specific electroencephalographic (EEG) patterns in neurooncologic patients. The algorithm provides selection of patients with their further classification into main and control groups based on the already existing database of EEG indicators; requests to it; generation of mono-indicator candidates for EEG-patterns on the basis of a 4-dipole table for selecting and verifying sensitive and specific EEG patterns and outlining the best ones. Our material included 368 patients with basal-diencephalic tumors. Algorithmic methods revealed new EEG patterns in patients with different anatomical and topographical variants of neuroepithelial tumors in the III ventricle. We think it reasonable to use the revealed syndromes to improve diagnosis and identify pathophysiological basis of clinical syndromes.

Primary leptomeningeal gliomatosis (PLG) is a rare condition, with fewer than 50 patients reported. Our report illustrates the natural history of PLG in full, from the prodromal phase of subacute meningitis to the final stages characterised by extensive nerve root infiltration, cranial nerve palsies and widespread peripheral neurogenic muscle wasting. We provide correlative neuroimaging with serial MRI, and present the first published positron emission tomography imaging of this condition. We emphasise the importance of considering PLG in the differential diagnosis of chronic aseptic meningitis, the difficulties of making the diagnosis ante mortem, and the utility and potential limitations of early meningeal biopsy in this condition., (Copyright © 2011. Published by Elsevier Ltd.)

Gliomatosis cerebri (GC) is a rare neuroepithelial tumor which includes 2 types. Type 1: A 12-year-old boy presented with headache and vomiting. MRI showed the diffuse long T2 signal intensity without enhancement in the right hemisphere. ¹¹C-Methionine PET showed local intense tracer accumulation. Type 2: A 59-year-old woman presented with right hemiparesis and headache. MRI revealed diffuse long T2 signal intensity in multiple lobes, and the left occipital lobe yielded heterogeneous enhancement. ¹¹C-Choline PET showed multiple hypermetabolic foci in the same areas. Our findings show that multiple tracer PET might not only reflect the true extent of GC infiltration but also evaluate GC malignant processes more accurately than MRI.

Introduction: gliomatosis cerebri is a diffuse astrocytic neoplasm that involves more than two lobes of the brain. Treatment is not well defined and the prognosis is considered poor., Methods: retrospective analysis of 22 patients with gliomatosis cerebri., Results: we identified 17 men and 5 women (median age 54 years) seen in a Division of Neuro-oncology over a 6 year period. Patients presented with focal sensorimotor or visual deficits (86.4%), seizures (36.4%), cognitive dysfunction (27.3%), or headache (27.3%), suggesting in some cases stroke, migraine, or limbic encephalitis. All patients had bilateral involvement; the regions involved included, temporal (19), basal ganglia (18), frontal (17), parietal (17), corpus callosum (10), and occipital (9). The most frequent pathological findings were grade III astrocytoma (36.4%), grade II astrocytoma (22.7%), and grade IV astrocytoma (18.3%). Nine patients were diagnosed within the first month of symptom development, 11 between the first month and 1 year, and 2 after one year. Seventeen patients received treatment with chemotherapy, radiotherapy or both, and 12 patients (70.6%) had a clinical or radiological response. The median follow-up was 13 months, median progression free survival 6 months, and median survival 9,5 months (15 months if the patients received treatment). Eight patients had thromboembolic events., Conclusions: gliomatosis cerebri has a variable clinical course. Treatment often results in clinical responses. In this study de median survival of patients who received treatment was similar to that reported in series of glioblastoma multiforme., (Published by Elservier España, S.L. All rights reserved.)

Introduction: The localization of tumors and epileptogenic foci within the somatosensory or language cortex of the brain of a child poses unique neurosurgical challenges. In the past, lesions in these regions were not treated aggressively for fear of inducing neurological deficits. As a result, while function may have been preserved, the underlying disease may not have been optimally treated, and repeat neurosurgical procedures were frequently required. Today, with the advent of preoperative brain mapping, image guidance or neuronavigation, and intraoperative monitoring, peri-Rolandic and language cortex lesions can be approached directly and definitively with a high degree of confidence that neurosurgical function will be maintained., Methods and Results: The preoperative brain maps can now be achieved with magnetic resonance imaging (MRI), functional MRI, magnetoencephalography, and diffusion tensor imaging. Image guidance systems have improved significantly and include the use of the intraoperative MRI. Somatosensory, motor, and brainstem auditory-evoked potentials are used as standard neuromonitoring techniques in many centers around the world. Added to this now is the use of continuous train-of-five monitoring of the integrity of the corticospinal tract while operating in the peri-Rolandic region., Conclusion: We are in an era where continued advancements can be expected in mapping additional pathways such as visual, memory, and hearing pathways. With these new advances, neurosurgeons can expect to significantly improve their surgical outcomes further.

The immunohistological features and surgical treatment of an intramedullary ependymal cyst in the conus medullaris is presented. An intramedullary ependymal cyst is a rare lesion of dysembryoplastic origin. There have been only seven patients reported with pathologically proven ependymal cysts in the conus medullaris. A 64-year-old woman reported pain and numbness in both thighs and feet. Neither sensory nor motor impairment was present in the lower extremities. MRI revealed a cyst on the right side of the conus medullaris, compressing the spinal cord upward. Clinical signs and symptoms disappeared following surgical resection of the cyst. Histological examination showed that this cyst was lined with a single layer of tall columnar or low cuboidal cells on fibrous connective tissue. The basement membrane was absent in the cyst wall. Reactivity to CAM5.2 and AE1/AE3 anti-keratin antibodies suggested that the cyst was of neuroepithelial origin. No recurrence has been noted 3 years after surgery., (Copyright 2009. Published by Elsevier Ltd.)

During the pre-surgical evaluation of drug-resistant epilepsy, the assessment of the extent of the epileptogenic zone and its organization is a crucial objective. Indeed, the epileptogenic zone may be organized as a simple focal lesional site or as a more complex network (often referred to as the 'epileptogenic network') extending beyond the lesion. This distinction is particularly relevant in developmental lesions such as focal cortical dysplasias or dysembryoplastic neuroepithelial tumours and may determine both the surgical strategy and the prognosis. In this study, we have quantified the epileptogenic characteristic of brain structures explored by depth electrodes in 36 patients investigated by stereoelectroencephalography and suffering from focal drug-resistant epilepsy associated with focal cortical dysplasias or dysembryoplastic neuroepithelial tumours. This quantification was performed using the 'Epileptogenicity Index' method that accounts for both the propensity of a brain area to generate rapid discharges and the time for this area to get involved in the seizure. Epileptogenicity Index values range from 0 (no epileptogenicity) to 1 (maximal epileptogenicity). We determined Epileptogenicity Index from signals recorded in distinct brain structures including the lesional site. We studied the type of epileptogenic zone organization (focal versus network) and looked for a correlation with clinical data and post-surgical outcome. Mean Epileptogenicity Index in lesional regions was 0.87 (+/-0.25), and 0.29 (+/-0.30) in 'non-lesional' structures. The number of highly epileptogenic structures (defined by Epileptogenicity Index value >or=0.4) was 3.14 (+/-1.87) in the whole population. We found that 31% of patients had only one epileptogenic structure (N(EI>or=0.4) = 1), therefore disclosing a strictly focal epileptogenic zone organization while 25 patients had more than one epileptogenic region, disclosing a network (61%) or bilateral (8%) epileptogenic zone organization. We observed a trend for a difference in seizure outcome according to the type of epileptogenic zone organization. Indeed, 57% of patients with network organization and 87% with focal organization were seizure-free while none of those with bilateral organization became seizure-free. The determination of Epileptogenicity Index computed from electrophysiological signals recorded according to the stereoelectroencephalography technique is a novel tool. Results suggest that it can help in the delineation of the epileptogenic zone associated with brain lesions and that it could be used in the definition of the subsequent surgical resection.

Introduction: Memory impairment caused by bilateral hippocampal primitive brain tumor is rarely reported. Clinical and MRI features can mimic paraneoplastic limbic encephalitis (PLE), and the differential diagnosis between these 2 entities may be difficult., Case Report: We report the case of a 42-year-old woman presenting with amnesia without neurologic focal signs at clinical examination. The neuroimaging features consisted of bilateral limbic hyperintensities on T2-weighted and FLAIR brain MRI. Despite exhaustive biologic and radiologic investigations, no specific etiology was found. The diagnosis of paraneoplastic limbic encephalitis was suspected, although antineuronal antibodies were negative and no cancer was detected after the first evaluation. Eight months after onset, the memory complaint of the patient increased along with disability in activities of the daily living, the neurologic examination slightly changed with frontal neurologic signs and the brain MRI showed a new cystic lesion in the left hippocampus with enhancement after contrast administration. The left temporal tumor was resected and the neuropathological examination was consistent with gliomatosis cerebri with a focal high grade astrocytoma., Conclusions: This case highlights the need to consider the possibility of infiltrative gliomatosis in patients presenting with features of paraneoplastic limbic encephalitis.

Introduction: Dysembryoplastic neuroepithelial tumors (DNTs) were first described by Daumas-Duport et al. in 1988 as a typically cortical tumor affecting young patients with long-standing, drug-resistant epilepsy., Methods: We reviewed the medical records of 29 patients with DNT between 1994 and 2007 at Hacettepe University Children's Hospital retrospectively; age at the time of surgery, age at seizure onset, electroencephalography (EEG), MRI, medical treatment, surgical procedure, seizure outcome, and pathological findings were documented., Results: Male to female ratio was 15/14. Age at the time of evaluation ranged 4-24 years. Twenty-seven patients (93.1%) had complex partial seizures, one (3.44%) had simple partial seizures, and one patient had generalized seizures. Preop interictal EEG showed epileptiform discharges in 24 patients, while in five patients interictal EEG before surgery showed no epileptiform discharges. Pathologically, 24 of our patients were classified as complex type and five as simple type. MRI showed temporal lesion in 20 (68.9%) patients and nine patients had extratemporal DNT. We choose the type of surgery according to lesion and the epileptojenic zone. Finally, 27 patients had Engel Class IA and two patients had Engel Class IB outcome., Conclusion: Complete resection of the lesion with epileptojenic zone is important for seizure-free outcome. Timing of surgery, extent of surgery, and stopping antiepileptic drugs are still important factors.

Objective: Gliomatosis cerebri (GC) is defined as a diffuse neoplastic glial cell infiltration of the brain with the preservation of anatomical architecture and the sparing of neurons and can be classified into Type 1 (diffuse) and Type 2 (mass forming) GCs macroscopically. There is little information on subtypes of GC. The aim of this study was to evaluate the clinicopathologic findings of GCs and to compare the clinicopathologic findings between Type 1 and Type 2 GCs., Material: A total of 33 cases of GC were obtained from pathology file of Samsung Medical Center. The diagnosis was based on magnetic resonance imaging findings and histological confirmation for all patients. Fifteen cases were classified into Type 1 and 18 were Type 2 based on the MR images., Methods: Clinical information included patients' age, sex, tumor extent, treatment modality and survival. Pathologic features included the amount of rod cells and cytologic anaplasia such as multinucleated tumor giant cells, endothelial cell proliferation, or mitosis. Immunohistochemical study was performed for GFAP, O1, Gal-C, Ki-67, and p53. Clinicopathologic comparison between subtypes and statistical analysis were performed., Results: Median age at diagnosis was older (56 years) in Type 1 than in Type 2 (44 years). Male to female ratio was about 1.54:1. Mean survival time was shorter (21 months) in Type 2 than in Type 1 GCs (24 months) (p = 0.0447). Histologically, 33 cases of GC were classified into two histologic grades (low and high grade) by cytologic anaplasia. High-grade GC was more common in Type 2 than Type 1 (p = 0.027). Immunohistochemical results demonstrated that the infiltrating tumor cells were undifferentiated cells with astrocytic or oligodendroglial differentiation. Ki-67 labeling index was correlated with subtypes (p = 0.0096). Pathologic features were not correlated with survival., Conclusions: Type 1 and 2 GCs are somewhat different in clinical presentation and pathologic features. The age group, survival time, histologic grade, and Ki-67 labeling index were significantly correlated with subtypes ofGCs. Type 2 GC was correlated with poor survival but histologic grade was not.

A 3-year-old girl presented with a dysembryoplastic neuroepithelial tumor in the right cingulate gyrus manifesting as epilepsy refractory to anticonvulsant medication. Computed tomography and magnetic resonance imaging revealed a cystic tumor in the right cingulate gyrus. The tumor was removed under intraoperative electrocorticography guidance. Abnormal spikes recorded adjacent to the tumor disappeared immediately after total removal. Histological examination showed a multinodular, multicystic structure, satisfying the criteria for the diagnosis of dysembryoplastic neuroepithelial tumor. She has remained seizure-free for more than 4 years without complications. In this case, intraoperative electrocorticography was very useful to identify the possible focus and prevent unnecessary resection of the adjacent tissue. Total removal of the tumor resulted in a dramatic reduction of seizure activity.

Background: Astroblastoma, an uncommon neuroepithelial tumor, typically presents in young adults as a well-circumscribed cortical or subcortical spherical mass. Astroblastoma may cause a diagnostic problem to anyone unfamiliar with its architectural and histological features., Case History: We report the case of a 4-year-old boy who was referred for complaints of progressive deficits of balance and difficulty with walking during the previous 3 months. A large fronto-parietal cystic mass with solid mural nodule was discovered. Total removal of the tumor mass was performed, and a diagnosis of high grade (malignant) variant of astroblastoma was made. Postoperatively, the patient received radiation therapy, for a period of 11 weeks, followed by chemotherapy. He is in a good neurological recovery without any evidence of recurrence for 8 months., Prognosis: The best treatment modality for astroblastoma is surgical resection if possible, whereas adjuvant therapy (radiotherapy and/or chemotherapy) can be considered in high-grade astroblastomas, with a close follow-up for all cases.

Purpose: Gliomatosis cerebri (GC) is a rare neoplastic disorder that may present as intractable epilepsy during early life. We report our experience regarding the evaluation and the surgical treatment of epilepsy in this population., Methods: All children evaluated between 1990 and 2006 for surgery of epilepsy (n = 741) with pathologically proven GC were selected., Results: We identified four male children with age at seizure onset ranging from 4 months to 11 years. Two had hemiparesis and one child with infantile spasms was developmentally delayed. Seizures occurred daily (n = 3) or monthly (n = 1). Ictal semiology was consistent with psychomotor seizures (n = 1), partial motor seizures (n = 2), and asymmetric epileptic spasms (n = 1). Surgery was symptomatic and aimed at debulking and controlling the epilepsy. Procedure was individually tailored based on the presurgical evaluation. Brain MRI revealed widespread hemispheric involvement (n = 3) or infiltration of the temporal lobe and basal ganglia (n = 1). Two patients were initially misdiagnosed as hemispheric cortical dysplasia and hemimegalencephaly. Scalp EEG was nonlocalizing in two cases, showed a right temporal focus in one case, and was not performed in one case. Interictal SPECT in one patient revealed widespread hemispheric hypoperfusion. Three cases were resected under ECoG guidance after a mean delay of 11 months after seizure onset. Following functional hemispherectomy (n = 1) or focal cortical resection (n = 2), all children were alive and seizure free with a mean follow-up of 48 months (2-5 years). No unexpected complication was reported. One nonoperated case was alive but still seizing after 15 months follow-up. Chemotherapy was associated in three cases., Conclusions: GC is a rare cause of medically resistant epilepsy that may present in early life. The lack of a discrete lesion may lead to diagnostic uncertainty, especially in infancy. Epilepsy surgery is an effective therapy that can improve quality of life.

Astroblastoma, a unique glial tumor, has been described in the literature in case reports and small series. Its rarity has prevented evidenced-based treatment stratification. An 8-year-old boy presented with signs and symptoms of raised intracranial pressure. Imaging studies of the brain demonstrated a large heterogeneously enhancing solid mass in the left frontal lobe with punctate calcifications and cystic components that created subfalcine and uncal herniation. After tumor resection, histological diagnosis revealed a high-grade cerebral astroblastoma. The child's postoperative recovery was complicated by hydrocephalus that necessitated placement of a ventriculoperitoneal shunt. Fifty-four months after undergoing gross total resection and adjuvant radiation therapy, the patient, now 12-years-old, remains tumor free and neurologically stable. Chemotherapy was reserved in the event of tumor recurrence. Since the first description of astroblastoma, its histopathological and clinical features have been debated. We review the histology, immunohistochemistry, and cytogenetics of astroblastoma as well as examine the current literature and treatment strategies for the management of both low and high-grade tumors. Continued clinical studies and longer patient follow-up with a tumor based registry would further clarify optimal treatment for this rare tumor.

We describe a 25-year-old male patient with primary diffuse leptomeningeal gliomatosis (PDLG) presenting with gait ataxia, positive Lhermitte's sign, double vision, and right abducens nerve palsy. Spinal magnetic resonance imaging showed extended intradural, extramedullary, contrast-enhancing masses with compression of the myelon. Spinal leptomeningeal biopsy revealed a pilocytic astrocytoma WHO grade I. Despite chemotherapy with vincristin and carboplatin, the patient died 2 months after admission. A thorough autopsy showed no evidence for primary neoplasms in brain, spine and optic nerve. Sequence analysis of tumor protein 53 gene (TP53) revealed a missense mutation in exon 5, and expression of phosphatase and tensin homolog (mutated in multiple advanced cancers 1) (PTEN) protein was not detected, which may have contributed to astrocytoma development. To our knowledge, this is the first definitive case of pilocytic astrocytoma presenting as PDLG.

Childhood cancer is a leading cause of mortality in children less than 15 years of age, accounting for about 10.4 of total childhood deaths [Robinson LL: In: Pizzo PA, Polack DA (eds) Principles and Practice of Pediatric Oncology, 3rd edn. Lippincott--Raven, Philadelphia--NewYork, 1997, pp. 1-10.]. As more aggressive therapeutic regimens have been adopted and ostensibly cured patients are being followed for longer periods of time, it has become increasingly clear that the treatment of cancer can have significant late effects on the growing child, one of the more troublesome of which is the induction of secondary malignancy. We report an 11-year-old child who, as supported by both clinical course and neuroimaging studies, developed an unusual complication eight years after completing therapy for acute lymphoblastic leukemia, gliomatosis cerebri.

Cells of the microglia/macrophage lineage represent an important component of different brain tumours. However, there is little information about the microglia/macrophage cell system in glioneuronal tumours and its possible contribution to the high epileptogenecity of these lesions. In the present study, the distribution of cells of the microglia/macrophage lineage was studied by immunocytochemistry for CD68 and human leucocyte antigen (HLA)-DR in a group of glioneuronal tumours, including gangliogliomas (GG, n = 30), and dysembryoplastic neuroepithelial tumours (DNT, n = 17), from patients with chronic intractable epilepsy. A significant number of microglia/macrophage cells were observed in the large majority of glioneuronal tumours, both within the tumour and in the peritumoral region. Activated microglial cells positive for HLA-DR were localized around blood vessels and clustered around tumour neuronal cells. The density of activated microglial cells correlated with the duration of epilepsy, as well as with the frequency of seizures prior to surgical resection. These observations indicate that the presence of cells of the microglial/macrophage cell system is a feature of glioneuronal tumours and is functionally related to epilepsy, either directly in epileptogenesis or through activation following seizure activity.

Object: The object was to describe the clinical, radiologic, and pathologic features of astroblastomas in an unselected group of children who were treated in a single institution during an 11-year period., Methods: Eight children with astroblastomas of the brain were examined. Diagnosis was based on cell morphology, vascular attachment of the cell main process, lack of an epithelial-free surface differentiation, and poor intercellular cohesiveness. In addition to sections, tumor smears and electron microscopy were required for demonstrating or confirming such features., Conclusions: Clinical findings seem to confirm an apparent predilection of astroblastomas for younger children (median age of onset, 5 years) and the existence of two prognostically different types of tumor-well differentiated (low grade) and anaplastic (high grade). Microscopic findings suggest a closer resemblance of tumor cells to astroblasts rather than to "tanycytes" or ependymal cells. It seems, however, that anaplastic astroblasts have a tendency to evolve toward, or be associated with, less differentiated cells, either neuroepithelial or sarcomatous.

The results of clinical and experimental studies on epilepsy associated with focal cortical dysplasia (FCD) are presented. We have been interested in the findings of abnormal increases in the numbers of small vessels in specimens of FCD resected from epilepsy patients. In the clinical study of 13 patients with epilepsy, specimens of FCD or dysembryoplastic neuroepithelial tumor (DNT) were examined using immunohistochemistry. The number of vessels in both lesions were greater than those in cortical specimens of autopsy cases without epilepsy. Because the vessels showed negative staining of VEGF, it was thought that the phenomenon of increase in the number of vessels was simply a hypervascularity, not a neovascularity. The local hypervascularity was expected to show local hyperperfusion in CBF-SPECT study, but interictal SPECT demonstrated local hypoperfusion and ictal SPECT showed hyperperfusion. This may have been caused by a functional change in those vessels. In the experimental study, we tried to make a new animal model of FCD to study epileptogenicity of FCD. When kainic acid had been infused into the neocortex in the neonatal rats, FCD was induced in adult Wistar rats. Histopathological examination revealed cortical dyslamination and abnormal neurons. On EEG, local spike bursts were elicited from the lesions, however, clinical seizures were not detected. Although the data are preliminary and observation over a longer period is required to determine whether spontaneous seizures will occur in this model, it is expected that this new model will be useful for studying epilepsy associated with FCD.

Distinction of gliomatosis cerebri (GC), a rare entity characterized by a widespread infiltration of the brain by tumor, from diffuse glioma is a difficult clinical problem. Most previously reported cases of GC have been autopsy cases because of the lack of objective and quantitative clinical diagnostic criteria. In order to better define this entity, we report the neuroradiological and pathological findings of three cases of GC. Three patients (one man and two women, aged 46-71 years) presented with symptoms of mild increased intracranial pressure, cognitive impairment, or seizure. Magnetic resonance imaging (MRI) was done with T1-weighted images after gadolinium injection, and with T2-weighted images and fluid attenuated inversion recovery (FLAIR) in all cases. Histological confirmation of glial proliferation was obtained in all cases by craniotomy. The topography of the tumoral infiltration was characteristic, involving mainly the white matter, basal ganglia, thalamus, and commissural fibers. More than two cerebral lobes were affected. Contrast enhancement was absent, and mass effects were minimal compared with the extent of tumoral infiltration, but one patient presented with a small frontal enhanced mass during the clinical course. The pathological analyses demonstrated infiltration of the brains by variably differentiated neoplastic glial cells with destruction of the myelin sheath, but the involved axis cylinder and neuronal cells were preserved. Diagnosis of GC should be faithful to the pathological diagnosis criteria of Scheinker and Evans, and therefore the precise assessment of MRI findings according to these criteria is required for clinical, antemortem diagnosis of GC.

The authors describe for the first time an unusual cerebral tumor with unique clinical history, composed of 3 components: pilocytic astrocytoma, vascular proliferations similar to those described as arteriovanous malformations, and a neoplastic ganglion component. These three components were intimately entangled and created the tumor mass. Thus the authors propose the term angioganglioglioma for this entity. The relation to the historically defined anglioglioma and tumors related to ganglioglioma and dysembryoplastic neuroepithelial tumor is discussed. The authors believe that this lesion, in regard to the clinical presentation (long course of the disease, clinical symptoms), is closely associated with ganglioglioma and, with other morphological features, also to angioglioma. Further, it may constitute a new distinct clinicopathological entity with neoplastic and hamartomatous features.

Object: Gliomatosis cerebri (GC), a rare entity characterized by a widespread infiltration of brain by tumor, lacks objective and quantitative diagnostic criteria. Single-voxel spectroscopy and chemical shift imaging (two-dimensional proton magnetic resonance [MR] spectroscopy) were performed using both short (20- or 22-msec) and long (135-msec) echo times in nine patients suffering from GC, nine patients with low-grade gliomas (LGGs), and 25 healthy volunteers to establish the precise metabolic pattern of this uncommon brain neoplasm., Methods: The gliomatosis infiltration was characterized by markedly elevated levels of creatine-phosphocreatine (Cr) and mvo-inositol (Ins), a reduced level of N-acetyl aspartate (NAA), and a moderately elevated level of choline-containing compounds (Cho). This pattern differs strikingly from LGGs, which are characterized by elevated levels of Cho and Ins, markedly reduced levels of NAA, and low-to-normal Cr concentrations. Although the distinction between GC and LGG, based on histological and MR imaging criteria, is a matter of debate, MR spectroscopy produces valuable information for the differentiation between these two entities and, hence, the choice of therapeutic strategy. It also provides new insight into the pathophysiology of GC because elevated Cr and Ins levels may be related to proliferation of glial elements or, more probably, activation of normal glia. Elevated levels of Cho reflect cellular proliferation and reduced NAA corresponds to reversible neuronal injury and/or focal invasion by the tumor process., Conclusions: Owing to the unfavorable clinical outcome associated with GC compared with that associated with LGG, the findings of this study illustrate the diagnostic and prognostic value of proton MR spectroscopy in the characterization of infiltrating gliomas.

A case of gliomatosis cerebri in a 27-year-old man showing various cranial nerve manifestations is described. He was diagnosed as having cranial mononeuritis multiplex (bilateral oculomotor nerve paralysis, left facial nerve paralysis, bulbar palsy manifestations, and hypoglossal nerve paralysis) and was hospitalized in the neurology department on August 1, 2000. Although he continued to visit the neurology department after discharge, his manifestations showed no improvement. He was sent to our department for brain biopsy in August 2001. A biopsy performed at the Sylvian fissure from the frontal lobe/temporal lobe cortex showed high intensity on T2-weighted and Flair magnetic resonance imaging (MRI). The pathological findings were diffuse low-grade astrocytoma infiltrating between the pia mater and the cerebral cortex. We believed that the astrocytoma spreading on the subpia mater was responsible for the various cranial nerve manifestations, and we started whole-brain irradiation (46 Gy) + interferon (IFN)-beta D.I.V. from September 2001. The pathological findings of the brain biopsy showed diffuse astrocytoma. The clinical presentation was dramatically improved after radiotherapy. It seemed that this tumor had spread along the subpia mater and subependyma. When he was discharged in early December, he walked by himself. The characteristic features of this case are that no lesion in the cerebellum or brain stem was found on MRI, even though the main manifestations were cerebello-brain stem manifestations, and biopsy of the cerebral cortex revealed astrocytoma. It should be noted that the clinical manifestations of astrocytoma in some cases are dissociated from the imaging observations.

Background and Purpose: MR imaging characteristics of gliomatosis cerebri reiterate the diffuse nature of this tumor but are nonspecific and thus may pose a diagnostic challenge. Because perfusion MR imaging can provide a physiologic map of the microcirculation, we compared the measured relative cerebral blood volume (rCBV) at perfusion imaging with histopathologic findings in gliomatosis cerebri. MR spectroscopic findings were also reviewed., Methods: Retrospective analysis was performed of conventional and perfusion MR images from seven patients with proved gliomatosis cerebri. The conventional MR images were evaluated for the presence or absence of contrast enhancement, necrosis, and extent of T2-weighted signal intensity abnormality. Dynamic contrast-enhanced T2*-weighted gradient-echo echo-planar images were acquired during the first pass of a bolus injection of gadopentetate dimeglumine. The rCBV was calculated by using nondiffusible tracer kinetics and expressed relative to normal-appearing white matter. Pathologic findings were reviewed in all patients and compared with the MR perfusion data. Multivoxel 2D chemical shift imaging proton MR spectroscopic data were available for three patients and single-voxel data for one patient., Results: Conventional MR images showed diffuse abnormality in all cases and absence of contrast enhancement in all but one case. Average rCBV range was 0.75-1.26 (mean, 1.02 +/- 0.42 [SD]). MR spectroscopic data revealed spectra consistent with presence of tumoral disease. Histopathologic review showed absence of vascular hyperplasia in all specimens., Conclusion: The low MR rCBV measurements of gliomatosis cerebri are in concordance with the lack of vascular hyperplasia found at histopathologic examination; thus, perfusion MR imaging provides useful adjunctive information that is not available from conventional MR imaging techniques.

Introduction: Gliomatosis cerebri is a rare form of malignant neoplastic glial transformation that involves large areas of the central nervous system., Objective: To describe clinical manifestations, pathognomonic neuroimaging findings and results of radiotherapy of gliomatosis cerebri., Patients and Methods: We review clinical records and neuroimaging studies of two patients with gliomatosis cerebri identified from the files of brain tumor registries of two university hospitals. One patient underwent radiotherapy after surgery., Results: Clinical manifestations and evolution were totally different in both patients despite the fact that both tumors had the same extension on neuroimaging studies. Magnetic resonance imaging revealed the extent of the lesion in both cases, comprising both cerebral hemispheres. Histopathological study revealed G-I and G-II astrocytomas. The patient treated with whole brain irradiation experienced clinical improvement and involution of the brain tumour on neuroimaging studies, and survived 20 months after surgery., Conclusions: Clinical manifestations of gliomatosis cerebri are protean. Therefore, neuroimaging studies and histopathological analysis of brain tissue allow the correct diagnosis. Radiotherapy may improve neurological function in some patients. However, it is necessary to compare the long-term evolution of treated and non-treated patients to evaluate clinical efficacy of radiotherapy.

The diagnosis of the rare disease Gliomatosis cerebri requires the correlation of clinical, radiological, and pathological findings. We report on two patients with intravitally diagnosed gliomatosis cerebri. Due to the unusually high malignancy of the tumor cells, diagnosis was complicated by atypical findings such as gadolinium enhancement in MRI and raised intracranial pressure. The clinical course, differential diagnosis, and literature are summarized briefly.

Five patients with dysembryoplastic neuroepithelial tumour (DNT) showing extensive secondary haemorrhage, a finding not previously associated with these neoplasms, are described. The clinical presentations, neuroimaging findings, and histopathological features of these patients are reviewed. One patient, a previously asymptomatic 12 year old girl, presented with an acute intracerebral haemorrhage into a DNT. A further four young adults with histories of intractable partial and generalised seizures dating from childhood showed significant chronic haemorrhages within DNT, the MRI appearances in one patient giving a false impression of a cavernoma. Histopathology disclosed vascular abnormalities within these tumours which, together with other factors discussed, may have predisposed these tumours to haemorrhage.

18-FDG and 11C methionine PET scans were performed on two patients with gliomatosis cerebri. The cortical grey matter was hypometabolic when compared with normal. The findings support the concept that the cerebral cortex becomes functionally disconnected in this disease owing to the infiltrative nature of the underlying tumour. This may account for the high incidence of dementia in the course of this disease. In one of the cases described here, there was clear evidence of progression from a discrete tumour mass of glioma to gliomatosis cerebri and this progression argues against the WHO classification of this disorder separately from glioma.

Dysembryoplastic neuroepithelial tumor (DNT) is a relatively new neuroepithelial neoplasm that was first described by Daumas-Duport et al. in 1988. It was incorporated in the revised World Health Organization classification of brain tumors in 1993. The authors present the first case of DNT reported in the Latin-American literature. A 16-year-old woman had been found at age of five years to have complex partial seizures accompanied by secondary generalization. She was treated with various anti-epileptic drugs but always with incomplete control of seizures activity. Neurological examination was normal. Magnetic resonance imaging demonstrated a lesion in the left temporal lobe. She underwent a craniotomy with complete resection of the tumor. Histological study showed atypical neuroglial proliferation characteristic of DNT. Monoclonal antibody immunostaining for glial fibrillary acidic protein and S-100 protein confirmed the glial component, and neuronal specific enolase and synaptophysin emphasized the neuronal component.