Nuevos paradigmas en el diagnóstico y tratamiento de los tumores neuroepiteliales disembrioplásticos (DNT) / New paradigms in the diagnosis and treatment of dysembryoplastic neuroepithelial tumors (DNT)

Introducción: Los tumores neuroepiteliales disembrioplásticos (DNT) han sido considerados lesiones benignas y estables, sin embargo existen casos que han presentado evoluciones inusuales a lo largo de su seguimiento. Objetivo: Analizar las características clínicas, imagenológicas, quirúrgicas y hallazgos anatomopatológicos de un grupo de pacientes con diagnóstico original de DNT e identificar características que puedan prever una evolución atípica de los mismos. Métodos: Se analizaron retrospectivamente historias clínicas de 65 pacientes con diagnóstico confirmado de DNT desde 1985 a 2016. Se evaluó clínica, imágenes, cirugía, anatomía patológica y evolución a largo plazo haciendo hincapié en la recidiva tumoral y sus relaciones con los hallazgos de imágenes y clínica. Para el análisis estadístico se utilizó el Test X2 y en las muestras donde el valor esperado era menor a 5 se usó el Test de Fisher. Para comparar medias se utilizó el t-test. Resultados: La distribución etaria mostró un leve predominio masculino 1; 1,7, con una edad promedio de presentación de síntomas de 6,6 años, con una edad promedio a la cirugía de 9,7 años. La localización más frecuente fue el lóbulo frontal con el 45%, seguido por el lóbulo temporal con el 38% de los casos. Se realizó exéresis total solo en el 42% (27/65) de los pacientes. La patología mostró patrones típicos de DNT en el 90% de los casos. Las imágenes prequirúrgicas mostraron patrones típicos en un 65% (42/65) de los pacientes y atípicos en un 35% (23/65). El 46% (30/65) de los pacientes presentaron recidiva tumoral a lo largo del seguimiento. El tiempo promedio de la aparición de la recidiva fue de 4.5 años (6 meses a 13 años ). Los pacientes que recidivaron todos habían tenido exéresis parciales (30/30), entre los que no recidivaron el 77% (27/35) tenía exéresis completa y 23% (8/35) exéresis parcial. El síntoma más frecuente en las recidivas fue la aparición de crisis convulsivas en un 77%. El tiempo de seguimiento promedio fue de 9,2 años (±6,9 DS), el 85% de los pacientes están sin crisis convulsivas y el 55% (36/65) de estos están sin medicación. Conclusión: A pesar del comportamiento benigno en la mayoría de los DNT existen pacientes que pueden presentar recidiva. Estas recidivas no necesariamente implican transformación maligna a pesar de los cambios en las imágenes y la patología que pueden encontrarse. La exéresis completa de la lesión en la primera cirugía ha demostrado ser el factor pronóstico más importante. El seguimiento debe ser estricto, ya que se han visto recidivas posteriores a periodos libres de enfermedad prolongados. Es muy importante realizar un exhaustivo análisis de las imágenes pre y post quirúrgica para poder identificar características que nos permitan predecir comportamientos inusuales.

Introduction: Neuroepithelial dysembrioplastic tumors (DNT) have long been considered benign, stable lesions. However, some patients have unusual presentations and disease course. Objectives: To analyze clinical, imaging, surgical and anatomopathological findings in a cohort of patients with an original diagnosis of DNT, and identify characteristics that may predict an atypical disease course. Methods: We retrospectively analyzed the clinical records of 65 patients with a diagnosis of DNT confirmed from 1985 to 2017. Relationships between long-term disease evolution, emphasizing tumor recurrence, and baseline clinical, imaging, surgical and histopathological findings were assessed. For inter-group comparisons between patients with versus without tumor recurrence, categorical variables were analyzed using Pearson χ2 analysis or Fisher's Exact Test, as appropriate, while continuous variable means were compared via unpaired Student's t-tests. Results: Males out-numbered females by a ratio of 1.7 to 1. The average age at presentation with symptoms was 6.6 years, with an average age at surgery of 9.7 years. The frontal and temporal lobes were the most frequent tumor locations, accounting for 45 and 38% of cases, respectively. Gross total resection was achieved in 42% (27/65) of patients. Pathology was typical of DNT in 90% of cases, while pre-surgical images exhibited typical findings in 65%, atypical in 35%. Thirty patients (46%) experienced tumor recurrence over the course of follow-up. The average time to recurrence was 4.5 years (6 months to 13 years). All patients who relapsed had initially undergone partial excision (30/30). Among those whose tumor did not recur, 23% (8/35) had undergone partial excision. The most frequent presenting symptom with recurrences was seizures, which occurred in 77%. Overall follow-up of patients has been 9.2 years (±6.9 SD), amongst whom 85% are currently seizure-free, and 55% require no seizure medication Conclusions: Despite the benign behavior of most DNT, almost half of patients experience tumor recurrence. These recurrences do not necessarily involve malignant transformation, despite imaging and pathology changes that may be encountered. Extent of tumor resection (gross vs. partial) is the strongest predictor of tumor recurrence. Vigilant long-term monitoring is indicated, because recurrences may occur after prolonged disease-free periods.

Tumor neuroepitelial disembrioplásico durante el embarazo. Reporte de un caso / Dysembryoplastic neuroepithelial tumor during pregnancy. A case report

Resumen ANTECEDENTES: el tumor neuroepitelial disembrioplásico es una neoplasia poco frecuente del sistema nervioso central que causa crisis convulsivas focales resistentes al tratamiento farmacológico en pacientes jóvenes; su manifestación durante el embarazo es excepcional. CASO CLÍNICO: paciente femenina de 33 años de edad, con antecedente de tres embarazos y que, durante el cuarto, en la semana 12, inició con crisis convulsivas. El diagnóstico, por resonancia magnética nuclear, fue de tumor en el lóbulo frontal izquierdo, razón por la que se vigiló estrechamente hasta el final del embarazo, que concluyó por parto, sin ninguna complicación. Debido a que en la segunda resonancia magnética se evidenció el crecimiento de la lesión, se decidió la resección quirúrgica. El diagnóstico histopatológico informó que se trató de un tumor neuroepitelial disembrioplásico. Aunque hubo una influencia del embarazo en el comportamiento y crecimiento de este tipo de tumor, no fue posible observar la expresión de receptores hormonales en las células del tumor y el tratamiento no se modificó por la gestación. CONCLUSIONES: la repercusión del embarazo en el tumor neuroepitelial disembrioplásico no se explica por la influencia de las hormonas; este tipo de tumor sigue siendo una neoplasia benigna en el contexto de una gestación, porque no ha mostrado complicaciones que pongan en riesgo la vida de la madre y su feto.

Abstract BACKGROUND: Dysembryoplastic neuroepithelial tumor is a less frequently primary central nervous system neoplasm that causes focal seizures resistant to pharmacological treatment in young patients and its presentation during pregnancy is very rare. CASE REPORT: We report here the case of a 33 years old woman who started with seizures at 12th week of her fourth gestation. She was diagnosed by cerebral magnetic resonance imaging with a left frontal lobe tumor and was observed carefully until the end of pregnancy solved by delivery without any complication. Second magnetic resonance was performed that evidenced enlargement of the injury, therefore resection was carried out and histopathological diagnosis was for dysembryoplastic neuroepithelial tumor. Although it was observed an influence of pregnancy on clinical behavior and growth of this kind of tumor we did not find expression of hormonal receptors in the cells of the lesion and treatment was not modified by gestation. CONCLUSIONS: So impact of pregnancy on dysembryoplastic neuroepithelial tumor is not explained by a hormonal influence and this kind of tumor stills being a benign neoplasm in the context of gestation, since it has shown no risk of maternal and fetal life threatening complications.

Dysembryoplastic Neuroepithelial Tumor: A case report

@#This reports a case of dysembryoplastic neuroepithelial tumor (DNET) in a 5-year old male presenting with visual hallucination and seizures. Diagnostic workup revealed a homogenous cystic tumor located in the right temporo-parietal area which was considered as a low grade glioma. The patient underwent endoscopic third ventriculostomy with complete tumor excision and biopsy, revealing NET. Findings were confirmed by immunohistochemical staining with glial fibrillary action protein (GFAP), Alcian blue and synaptophysin. DNET is a recently described intracranial tumor under the World Health Organization classification of central nervous system (CNS) tumors. It is a unique entity of neuroglial tumors with excellent prognosis. Its worldwide incidence among all neuroepithelial tumors is 1.2% in patients under 20 years and 0.2% among patients over 20 years. This is the first case of DNET in the country as well as in our institution. Key points on the clinical manifestation, approach to diagnosis, distinctive radiologic and histopathologic characteristics, and management are discussed.

Dysembryoplastic neuroepithelial tumor: A rare case report.

Dysembryoplastic neuroepithelial tumor (DNET) is a rare benign tumor generally seen in children and adolescents with intractable epilepsy. This tumor demonstrates typical histological features such as glial nodules and the so called glioneuronal element. The diagnosis of DNET cannot rely just upon imaging features but needs a multidisciplinary contribution from the clinical and diagnostic department involving the clinician, radiologist as well as the pathologist to reach a definite and conclusive diagnosis. However histopathology is the gold standard for the final diagnosis.

Dysembryoplastic Neuroepithelial Tumors

Dysembryoplastic neuroepithelial tumor (DNT) is a benign glioneuronal neoplasm that most commonly occurs in children and young adults and may present with medically intractable, chronic seizures. Radiologically, this tumor is characterized by a cortical topography and lack of mass effect or perilesional edema. Partial complex seizures are the most common presentation. Three histologic subtypes of DNTs have been described. Histologically, the recognition of a unique, specific glioneuronal element in brain tumor samples from patients with medically intractable, chronic epilepsy serves as a diagnostic feature for complex or simple DNT types. However, nonspecific DNT has diagnostic difficulty because its histology is indistinguishable from conventional gliomas and because a specific glioneuronal element and/or multinodularity are absent. This review will focus on the clinical, radiographic, histopathological, and immunohistochemical features as well as the molecular genetics of all three variants of DNTs. The histological and cytological differential diagnoses for this lesion, especially the nonspecific variant, will be discussed.

Magnetic resonance imaging diagnosis of dysembryoplastic neuroepithelial tumor in children / 中华实用儿科临床杂志

Objective To study magnetic resonance imaging(MRI) features of dysembryoplastic neuroepithelial tumor(DNT) and to improve accurate diagnosis of DNT.Methods The MRI appearance and clinical features of 10 patients with DNT confirmed by surgery and pathology were analyzed retrospectively.Results In 10 cases,9 tumors located in supratentorial hemisphere cortex,3 tumors located in the temporal lobe,5 in the frontal lobe,1 in the parietal lobe,and 2 of them encroached the adjacent white matter.In 9 tumors located in supratentorial hemisphere cortex,8 cases had decreased signal intensity on T1-weighted MR images,1 case iso-decreased mixed signal intensity on T1-weighted MR images,and 9 cases increased signal intensity on T2-weighted images,9 cases slightly increased signal intensity on fluid attenuated inversion recovery weighted images.The manifestation of tumors was cystic or cystic partially oriented and was seen separate section intratumoral in some cases.Three cases appeared as hyperintense ring sign and internal septation,2 cases appeared as a triangle in shape,3 cases appeared as gyms-like shape,and 1 case as round shape,similar to cyst.Nine tumors had no significant mass effect and peritumoral edema.Enhanced MR imaging showed only 1 case with slight and heterogeneous enhancement,the rest 6 cases showed non enhancement.One case located in cerebellar hemisphere,and appeared cystic-solid mass,the solid part had decreased signal intensity on T1-weighted MR images,and increased signal intensity on T2-weighted images,the cystic part had decreased signal intensity on T1-weighted MR images,and increased signal intensity on T2-weighted images.On enhanced MR imaging,the wall-node obviously contrast enhancement,cyst wall slightly contrast enhancement,cystic part non enhancement.The tumor had peritumoral edema and mass effect.Ten cases had no hemorrhage and calcification.Conclusion The MRI appearance of DNT is characteristic and is helpful for the preoperative diagnosis of DNT.

Tumor neuroepitelial disembrioplásico: presentación de caso y revisión de la literatura / Dysembryoplastic Neuroepithelial Tumor (DNT): Case Presentation and Literature Review

El tumor neuroepitelial disembrioplásico (DNT) fue descrito por primera vezpor Daumas-Duport, en 1988, e incorporado a la clasificación de tumores de laOrganización Mundial de la Salud, desde 1993, como parte del grupo de tumoresneurogliales. El artículo describe un caso típico, dada su presentación clínica, hallazgosimaginólógicos e histológicos, con adecuada evolución postoperatoria. Se haceuna revisión de la literatura del DNT, describiendo su epidemiología, presentaciónclínica, hallazgos imaginólógicos e histológicos, posibilidades de tratamiento actualy pronóstico...

Dysembryoplastic neuroepithelial tumors (DNT)were first described by Daumas-Duport in 1988and incorporated into the new World Health Organizationclassification of brain tumours as partof the group of glioneuronal tumours in 1993. Wedescribe a typical case due to its clinical presentation,image and hystologic findings, with goodpostoperative course. A review of the literatureof DNT is made, describing its epidemiology,clinical presentation, image and histological findings,current treatment options and prognosis...

Dysembryoplastic neuroepithelial tumor originally diagnosed as astrocytoma and oligodendroglioma / Tumor neuroepitelial disembrioplásico diagnosticado originalmente como astrocitoma ou oligodendroglioma

Dysembryoplastic neuroepithelial tumor (DNT), described in 1988 and introduced in the WHO classification in 1993, affects predominantly children or young adults causing intractable complex partial seizures. Since it is benign and treated with surgical resection, its recognition is important. It has similarities with low-grade gliomas and gangliogliomas, which may recur and become malignant. OBJECTIVES: To investigate whether DNT was previously diagnosed as astrocytoma, oligodendroglioma, or ganglioglioma and to determine its frequency in a series of low-grade glial/glio-neuronal tumors. METHODS: Clinical, radiological, and histological aspects of 58 tumors operated from 1978 to 2008, classified as astrocytomas (32, including 8 pilocytic), oligodendrogliomas (12), gangliogliomas (7), and DNT (7), were reviewed. RESULTS: Four new DNT, one operated before 1993, previously classified as astrocytoma (3) and oligodendroglioma (1), were identified. One DNT diagnosed in 2002 was classified once more as angiocentric glioma. Therefore, 10 DNT (17.2%) were identified. CONCLUSIONS: Clinical-radiological and histopathological correlations have contributed to diagnose the DNT.

O tumor neuroepitelial disembrioplásico (DNT), descrito em 1988 e incorporado na classificação da OMS em 1993, acomete predominantemente crianças ou adultos jovens, causando crises convulsivas parciais complexas farmacorresistentes. Como é benigno e tratável com ressecção cirúrgica, seu reconhecimento é importante. Tem semelhanças com gliomas de baixo grau e gangliogliomas, que podem recidivar e malignizar. OBJETIVOS: Investigar se o DNT foi originalmente diagnosticado como astrocitoma, oligodendroglioma ou ganglioglioma e determinar sua frequência numa série de neoplasias gliais/glioneuronais de baixo grau. MÉTODOS: Foram revistos aspectos clínicos, radiológicos e histológicos de 58 neoplasias operadas entre 1978 e 2008, classificadas como astrocitomas (32, sendo 8 pilocíticas), oligodendrogliomas (12), gangliogliomas (7) e DNT (7). RESULTADOS: Foram identificados quatro novos DNT, um operado antes de 1993, originalmente diagnosticado como astrocitoma (3) e oligodendroglioma (1). Um DNT diagnosticado em 2002 foi reclassificado como glioma angiocêntrico. Portanto, 10 DNT (17,2%) foram identificados. CONCLUSÕES: Correlações clínico-radiológicas e histopatológicas contribuíram para o diagnóstico do DNT.

Diffuse Ependymal Dysembryoplastic Neuroepithelial Tumor Causing Spinal Drop Metastases: A Case Report

Dysembryoplastic neuroepithelial tumors (DNETs) arise mostly in the supratentorial cerebral cortex. A very rare case of intraventricular DNET with diffuse ependymal involvement, which causes spinal drop metastasis, is presented.

CT and MR Imaging Features of Dysembryoplastic Neuroepithelial Tumor / 实用放射学杂志

Objective To analyze CT and MR imaging features of dysembryoplastic neuroepithelial tumor(DNT),so that to improve its diagnostic accuracy.Methods CT and MRI fidnings of DNT in 10 cases proved surgically and pathologically were retrospectively reviewed.Results All lesions were located in the super-tentorial gray matter regions or involved the cererbral certex mainly.The lesions were round,lobular,triangular or irregular pseudocystic masses with definite borders mostly.The lesions were hypointense on T_1WI and hyperintense on T_2WI.On fluid attenuated inversion recovery weighted images,the hyperintense "ring sign" and septa of the lesions were seen.On diffuse-weighted images(DWI),the lesions were hypointense or slight hypointense.On MR spectroscopy,NAA of the lesions slightly decreased.There were no peripheral edema and mass effect with well-demarcated.7 lesions had no enhancement and 3 lesions had slight unhomogeneous enhancement after administration of contrast medium.The lesions in 2 cases on plain CT showed low attenuation and one had calcification inside the lesion.Conclusion DNTs are of typical neuroradiologic features,that may be helpful for the diagnosis of which preoperatively.

MRI Features of Dysembryoplastic Neuroepithelial Tumors / 实用放射学杂志

Objective To study MR imaging features of dysembryoplastic neuroepithelial tumors (DNET). Methods MRI ap-pearances of 10 patients with surgery and pathology proved DNET were analyzed retrospectively. All of 10 patients underwent routine and contrast-enhanced MRI. Results All lesions were located in the regions near the surface of brain,including frontal lobe (4 ca-ses) ,parietal lobe (4 cases),temporal lobe (1 case) and parietoinsular lobe (1 case). The lesions appeared as sector in 4 cases, re-versed triangle in 4 cases,irregularity in 2 cases. Homogeneous or heterogeneous long T_1 and long Tz signal intensity were seen on MR imaging. The lesion showed predominant cystic component and septa, no obvious mass effect and peritumoral edema could be found in all cases. Bone thinning of the adjacent calvaria could be seen in 6 cases. On post contrast MRI scan,the lesions had no obvi-ous enhancement in 6 cases ,while mild enhancement could be found in the intra-tumorous solid nodule or septations in 4 cases. Conclusion DNETs are of certain clinical manifestations and MRI features,it is helpful for preoperative diagnosis of DNET.

MRI Features of Dysembryoplastic Neuroepithelial Tumor / 实用放射学杂志

Objective To investigate MRI features of dysembryoplastic neuroepithelial tumor(DNT).Methods The MR images of ten cases with surgically and pathologically proved DNT were retrospectively reviewed.Results MR imaging showed cystic component with mural nodule in 6,mainly cystic component with septa in 3.The solid components of the tumors were long T_1 and long T_2 signal intensity,the cystic components were even longer T_1 and T_2 signal intensity which resembled the signal of cerebrospinal fluid.Mild enhancement could be found at the intra-tumoral solid nodule or septations after injection of constrast medium but the cystic component did not show any enhancement.No peri-tumoral edema and mass effect were found in most cases.Conclusion DNTs are of some special features on the MR images,the diagnosis can be exactly done before operation if MRI features in combination with clinical data of the patients.

Surgical Treatment of Intractable Epilepsy with Benign Brain Lesion / 대한간질학회지

Epilepsy surgery can be a safe, effective treatment for individuals with intractable partial epilepsy. There is increasing evidence that brain abnormalities in focal epilepsy are not restricted to a single area. The longstanding debate around the relationship between structural lesions and the epileptic zone remains unresolved. Patients with DNT (dysembryoplastic neuroepithelial tumor), which is an essentially benign tumor, can be cured by epilepsy surgery-oriented approach. Cortical dysplasia is frequently associated with DNT and seems to contribute to epileptogenic activity of DNT. Surgical treatment should be aimed at removal of the associated cortical dysplasia as well as DNT itself for ideal treatment of the disease. Simple lesionectomy of cavernous angioma would relieve seizures significantly, but not always. The concept of epilepsy surgery needs to be recruited in the treatment of cavernous angioma with seizures because diffusion of hemosiderin into the surrounding brain tissue and formation of cortical scars can make epileptogenic areas. Cortical dysplasia is a highly epileptogenic lesion constituting an important cause of medically intractable epilepsy and surgery is a treatment of choice in a selected group of patients. Identification and complete resection of the lesion and ictal onset zone are necessary to achieve a good surgical results. Intractable epilepsy accompanied by benign brain lesions can be treated surgically using the entire armamentarium of presurgical investigations. Deliberate resective procedures aimed at complete removal of dysplastic tissue and epiletogenically active areas on and around the lesion ensure excellent seizure control without permanent neurologic deficit.

Dysembryoplastic neuroepithelial tumor : A case report.

We report on a classic case of dysembryoplastic neuroepithelial tumor (DNT) located in the right temporal lobe of a 12-years-old Thai boy presenting with visual, auditory and gustatory hallucinations for 4 years. DNT is an uncommon low-grade neuronal and mixed neuronal-glial tumor which has a characteristic clinical presentation, as well as characteristic radiological and histopathological finding. DNT has excellent prognosis and surgery is mainly curative treatment. Hence, it is important to recognize this entity in order to avoid unwarranted radio-or chemotherapy.

Dysembryoplastic Neuroepithelial Tumor in the Cerebellum: Case Report

Dysembryoplastic neuroepithelial tumor(DNT) is described by Daumas-Duport in 1988 and it was interpreted as low grade astrocytoma, oligodendroglioma, and mixed oligoastrocytoma previously. In recently revised World Health Organization classification of brain tumors, DNT is classified under 'neuronal and mixed neuronalglial tumor'. DNT is clinicopathologically unique tumor and commonly located in the temporal lobe associated with intractable complex partial seizure in young patients. We report a rare case of DNT located in the cerebellum.

A Case of Recurrent Dysembryoplastic Neuroepithelial Tumor in the Temporal Lobe / 대한간질학회지

A boy since 6 years of his age who have had complex partial seizure was referred to our Department in March 1998. The left anterior temporal lobectomy with the resection of the head and body of hippocampus and gross total tumor removal was also performed in April 1998. He has been seizure free and stable about 3 years postoperatively. In January 2001, he revisited us due to headache, nausea, and vomiting from one week before. MRI revealed recurrence of the tumor, and a partial removal of the tumor was performed. Nine months from the second operation, the tumor recurred again and the thrid operation was followed. The pathologic findings were dysembryoplastic neuroepithelial tumor (DNT) in all three cases and no evidences of anaplastic changes were found in two recurrent cases. In general, DNT is known to be a disease that rarely transforms into the malignant, postoperative adjuvant radio-or chemotherapy is unnecessary even after partial resection of the tumor. However, in our case, there were two episodes of recurrence after the total resection. Here, we report the first case of recurrent DNT even after the total resection within three years in our knowledge.

Epileptogenic Zones in Intractable Epilepsy Patients with Dysembryoplastic neuroepithelial tumor

BACKGROUNDS: A dysembryoplastic neuroepithelial tumor (DNT) is an important cause of the intractable epilepsy. The prognosis after epileptic surgery was excellent when the epileptogenic zones were completely excised. But, the exact epileptogenic zones in epilepsy patients with DNT are not well known. The purpose of this study was to investigate where the epileptogenic zones were in epilepsy patients with DNT. That results might be helpful in having good results of epileptic surgery of DNT. METHODS: Six patients with medically determined intractable epilepsy due to DNT were studied retrospectively. They had undergone epileptic surgery after video-EEG monitoring not only with scalp electrodes but also with invasive subdural electrodes. DNTs were located in the temporal lobe and pathologically proven in all patients. We analyzed distributions of ictal onset zones and irritative zones with non-invasive and invasive Video-EEG monitoring. Also, we reviewed the clinical features, neuroimaging features, neuropsychological tests, Wada tests and pathological findings. The operative strategy included complete resection of DNT, ictal onset and irritative zones in all patients. In two patients, modified operative strategy including amygdalohippocampectomy was done due to mesial involvement. A modified Engel's classification was used to determine surgical outcomes. RESULTS: The irritative zones (included only more than 10% of total interictal discharges during the monitoring) showed various patterns from multifocal to unobserved. Ictal onset zones were multiple in 5 patients (dual: 3 patients, triple: 2 patients). In 1 patient, contralateral hemispheric mirror focus was observed. Mesial temporal involvement was seen in 2 patients from EEG and in 1 patient from pathology. There were discrepancies between ictal onset zones and irritative zones in 4 patients. The EEG seizures without clinical events were recorded in 1 patient. Postoperatively 5 patients were free of seizure, 1 patient had rare seizures. CONCLUSION: Not only the wide or multiple distribution of epileptogenic zones around or in the lesion but also dual pathology of hippocampus are possible in epilepsy patients with DNT. The operative strategy including the epileptogenic zones can yield a good surgical outcome.

Dysembryoplastic Neuroepithelial Tumor: A Case Report

We report the case of a 12 year old boy with a dysembryoplastic neuroepithelial tumor(DNT) of the left frontal lobe. Only recently recognized, this tumor is an uncommon neurosurgical lesion of adolescents and young adults, one with a benign clinical course and a long history of intractable partial complex seizures. DNT was first proposed by Daumas-Duport et al. and in the revised WHO histological classification, has recently been incorporated into the category of neuronal and mixed neuronal-glial tumors. Since the first description, there have been a few additional case reports of DNTs, including histological and radiological findings. Owing to the supratentorial and intracortical location of this tumor, and its association with cortical dysplasia, the onset of seizure is often early, either in childhood or adolescence. Unlike other dysgenetic lesions and some glial tumors, the prognosis after resection is thought-as far as seizure control is concerned-to be excellent. Identification of these neoplasms is of obvious therapeutic importance because it spares these young patients the deleterious long term effects of radio-or chemotherapy.

Coexistence of Neoplasia and Cortical Dysplasia Associated with Intractable Epilepsy: A Clinical Study of Seven Surgical Patients and Surgical Strategies

A tumor and cortical dysplasia may be the concomitant cause of the causes of intractable epilepsy, but a few studies have examined so far. From among 249 patients who underwent surgery for intractable epilepsy at Dongsan Epilepsy Center, those in whom neoplasia and cortical dysplasia coexisted were selected for this study, and were reviewed the clinical, electrophysiological, neuroimaging and pathological findings. In 17 of 25 lesionrelated epilepsy patients, tumors including dysembryoplastic neuroepithelial tumor(DNT)(n=6), ganglioglioma(n=5), gangliocytoma(n=1), low grade astrocytoma(n=2), oligodendroglioma(n=2), hypothalamic hamartoma(n=1) were verified. Of these 17 cases involving tumors, concomitant cortical dysplasia was observed in 7(DNT; 6, ganglioglioma; 1). All these patients underwent sophisticated presurgical evaluation and intraoperative acute recording(EcoG) for the identification of adjacent or remote epileptogenic areas as well as functional brain mapping by electrical stimulation or SSEP to verify the eloquent areas. In intractable epilepsy, the coexistence of cortical dysplasia and neoplasia is not common, though careful intraoperative evaluation of the tumor and surrounding tissue using electrocorticogram (EcoG) may lead to its pathological identification and excellent surgical results for these rare lesions.