Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dysembryoplastic neuroepithelial tumor (DNT) is a rare, benign tumor encountered in the cortex. It is characterized by the presence of cells of different histogenesis. Due to its mixed nature (glial-neuronal), WHO histological classification of brain tumors included it into the group of neuronal and glial-neuronal mixed tumors. Case of tumor in a 19-year-old woman experiencing for three years seizure of temporal lobe epilepsy is presented. A cranial magnetic resonance imaging (MRI) showed "pseudocystic" tumor in temporal lobe. Histological and immunocytochemical examinations of the tumor fragment removed during surgery revealed large numbers of neuronalglial nodules occurring in the cerebral cortex. Columns of glial-neuronal structures crossing parallely to the cortex surface, surrounded by oligodendrocyte-like cells (OLC) were a characteristic feature of the tumor texture. In the tumor interstitium, "floating" maturated, dysplastic-free ganglionic cells were visible in numerous bright spaces. In addition, numerous lobuliform--structured areas consisted of oligodendrocyte-like cells. Oligodendrocyte-like cells were characterized by positive immunoreaction to the presence of S-100 protein and synaptophysin. Basing on clinical manifestation and histopathological findings dysembryoplastic neuroepithelial tumor was diagnosed.
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PMID:Dysembryoplastic neuroepithelial tumor. A case report. 1058 51

We report six cases od DNT with a detailed ultrastructural characteristics. The patient age ranged from 7 to 16 years (mean 12), the location was temporal in three cases and frontal, temporooccipital and parietooccipital in each of one remaining cases. The predominant clinical feature in each case was history of episodes of intractable seizures. Histopathologically, the neoplasms were multinodular, each nodule was well-circumscribed and was composed of glioneuronal elements embedded in the variable amount of myxoid matrix. The oligodendroglial-like cells (OLC) predominated in the nodules with some accompanying mature neurons. The nodules were frequently surrounded by small calcifications which could be found also within the tumors. OLCs were immunoreactive for S-100 protein and neurons had the expression of synaptophysin and neurofilament proteins. Ultrastructurally, each tumor consisted of three major elements: neoplastic cells (OLC), elongated processes forming neuropil-like structure and expanded "mucoid" extracellular space: the latter gave an impression of cellular elements floating within it. Neoplastic cells had round, oval or elongated nuclei, no discernible nucleoli and a relatively narrow rim of the cytoplasm. Some nuclei were irregular and invaginated and pseudoinclusions were observed; a part of cytoplasm sequestered within pseudoinclusions often appeared degenerated with large blabs and electron-lucent vesicles, some of these contained in turn semicircular profiles of unknown significance. The second element consisted of innumerable cellular processes. Some of these were elongated and formed stacks connected by symmetrical symmetric or asymmetric adhesive plaque junctions. The others had shorter "neck" containing microtubules, these extended into bullous extensions. Dense-cored vesicles were occasionally observed, in both cytoplasm of neoplastic cells and within processes. In one cell, cross-sectioned annulate lamellae were found. In cytoplasm of a few cells, unusual inclusions reminiscent ribosome-lamellae complexes were observed. These were cylindrical resembling "laboratory tubes" with a cone-like endings. At higher power, walls of the "tubes" resolved into layered structures composed of several laminae; between laminae, ribosome-like structures were visible.
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PMID:Dysembryoplastic neuroepithelial tumor (DNT): an ultrastructural study of six cases. 1058 52

Dysembryoplastic neuroepithelial tumour (DNT) is a rare low-grade, mixed neuronal and glial tumour, usually associated with pharmacologically intractable, complex partial or generalised seizures which date from childhood. The prognosis after surgery is favourable. We present a classic case of DNT occurring in an 18-year-old male, who presented simple partial seizures without signs of raised intracranial pressure. CT and MR demonstrated focal mass located in the right temporal lobe. Histologically there were found the features of a typical DNT architecture with mixed cellular composition. The response to surgery was excellent. The tumour has not recurred, and the control of seizures remained good. Immunostaining for glutamate receptor GluR-2 showed stronger immunopositivity in neurones dispersed within the tumour and especially in margins of lesion as compared with apparently normal cerebral cortex. The expression of both excitatoryamino acid transporterproteins EAAT1 and EAAT2 was weaker then in normal cortex and uneven. This perhaps may explain the mechanism of seizures (elevated glutaminergic stimulation), and may suggest the excitotoxic damage of neurones.
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PMID:Dysembryoplastic neuroepithelial tumour (DNT). Is the mechanism of seizures related to glutamate? An immunohistochemical study. 1168 Jun 32

Pure neuronal and mixed neuronal-glial tumors of the central nervous system are uncommon but fascinating because they are less aggressive than the more common glial tumors and their prognosis is excellent. Neurologic manifestations are varied and include seizures, symptoms of increased intracranial pressure, and neurologic deficits according to tumor location. Many neuronal tumors of the central nervous system demonstrate characteristic radiologic findings. At magnetic resonance (MR) imaging, gangliocytomas demonstrate low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and frequent enhancement on gadolinium-enhanced T1-weighted images. Characteristic MR imaging findings of Lhermitte-Duclos disease are a nonenhancing mass in a cerebellar hemisphere with a striated pattern. Central neurocytomas are typically located in the lateral ventricles near the foramen of Monro with a characteristic attachment to the septum pellucidum. Ganglioneurocytoma is a rare variant of central neurocytoma that is characterized by differentiation toward ganglion cells. In ganglioglioma, a well-defined cystic mass with a solid mural nodule is typically seen. Extension of enhancement to the leptomeninges is characteristic of desmoplastic infantile ganglioglioma and correlates with the firm dural attachment of the solid component. Dysembryoplastic neuroepithelial tumor has a well-demarcated, multilobulated or gyriform appearance.
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PMID:Neuronal tumors of the central nervous system: radiologic findings and pathologic correlation. 1223 46

Dysembryoplastic neuroepithelial tumors DNTs are highly polymorphic tumors that arise during embryogenesis. They are preferentially, but not exclusively, located in the supratentorial cortex. Histologically they may mimic any categories of low-grade or even of high-grade gliomas, but from a carcinological point of view, they behave as stable lesions. Their differential diagnosis from gliomas is obviously important to spare these young patients with a normal life expectancy the long- term deleterious effect of radiation or chemotherapy. The diagnosis of DNT must be considered when all the following criteria are present: partial seizures with or without secondary generalization, no neurological deficit or a stable congenital deficit, cortical topography on MRI, absence of peri-tumoral edema and of mass effect. In other locations, the diagnosis of DNT has to be suspected in case of discordance between the neurological status of the patient and the topography of the tumor or of unusual radiological features such as contrast enhancement but no mass effect and no edema. Supratentorial cortical DNTs tend now to be detected more systematically by imaging soon after first seizures. In most instances, the epilepsy can be cured by gross total surgical removal. Surgery also allows to prevent the risks of intratumoral hematoma or infarct. DNTs should therefore be operated soon after diagnosis. However, excellent results can also be obtained by epilepsy surgery in patients with long term drug resistant partial seizures.
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PMID:[Dysembryoplastic neuroepithelial tumors]. 1291 70

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.
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PMID:Distribution, characterization and clinical significance of microglia in glioneuronal tumours from patients with chronic intractable epilepsy. 1588 65

Dysembryoplastic neuroepithelial tumor (DNT) is a well-known epileptogenic lesion with favorable seizure outcome after surgical resection. However, sometimes surgery may be difficult technically, and epilepsy may continue throughout the patient's lifetime despite surgical intervention. We report a case of intractable epilepsy related to DNT that was treated with gamma knife radiosurgery (GKRS). The frequency of seizure was reduced remarkably after GKRS, and finally a seizure-free state was accomplished in two years. Neuropsychological tests also showed improvement. It is suggested that GKRS may be an effective and less invasive alternative treatment for the patients in whom surgical treatment is difficult.
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PMID:Gamma knife radiosurgery for epilepsy related to dysembryoplastic neuroepithelial tumor. 1706 46

Dysembryoplastic neuroepithelial tumors (DNETs) are benign supratentorial tumors based in the cerebral cortex. They usually are found in children and young adults with seizures that tend to become refractory to medical treatment. In the vast majority of cases resection results in good seizure control, and adjuvant therapy is not required. When tumors thought to be DNETs are not resected due to their proximity to eloquent cortex, lack of change in the clinical and neuroimaging features over time supports the diagnosis of DNET. The authors report on a patient in whom a pilocytic astrocytoma developed within a DNET, raising questions regarding the classification of these lesions and the need for lifelong clinical and imaging surveillance. This paper adds to the growing body of literature about the biological behavior of these lesions.
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PMID:Development of a pilocytic astrocytoma in a dysembryoplastic neuroepithelial tumor. Case report. 1756 12

Dysembryoplastic neuroepithelial tumours (DNETs) were incorporated into the new World Health Organization classification of brain tumours as part of the group of glioneuronal tumours in 1993. Large series of patients with DNETs and pharmaco-resistant epilepsy have been reported. DNETs are most often located in the temporal lobe, occurring in both mesial and lateral temporal locations. DNETs have also been reported in the insular cortex, brain stem, cerebellum, occipital lobe and striatum. Approximately 40% of DNETs are cystic, and solitary nodular, multinodular or diffuse forms have been recognized. Approximately 30% of DNETs are associated with subtle cortical dysplastic changes in the adjacent cortex. DNET nodules usually look like oligodendroglioma, whilst between the nodules it may be possible to recognize vertical columns of neurons surrounded by oligodendrocyte-like cells. Cytologically, oligodendroglial-like cells of DNETs are distinguished from oligodendroglioma by larger nuclei with frequent nuclear indentations and multiple, small nucleoli, whilst oligodendrogliomas consistently show nuclear roundness with one or two occasional nucleoli. Very rare cases of malignant transformation have been reported. DNETs are hypodense on CT and demonstrate decreased signal on the T1-weighted images and a hyper-intense signal on T2-weighted MRI. DNETs associated with pharmaco-resistant epilepsy should be removed early to achieve seizure freedom and prevent tumour progression. The surgical approach should be that of an extended lesionectomy, i.e. excision of the lesion and the abnormal dysplastic cortex around it. Use of MRI-based image guidance (neuronavigation) as a surgical tool to identify this area of abnormal cortex is very helpful to ensure that the extended lesionectomy includes any visibly dysplastic cortex. It is not advocated to use a stereotactic biopsy only, as this may generate an unrepresentative tissue sample consisting of an oligodendroglial component only and may lead to an incorrect diagnosis.
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PMID:The Children's Cancer and Leukaemia Group guidelines for the diagnosis and management of dysembryoplastic neuroepithelial tumours. 1807 81

Dysembryoplastic neuroepithelial tumor (DNT) is an increasingly recognized surgically curable tumor that characteristically presents with seizures in children. We report a case of a patient who underwent resection of a histologically proven DNT at 6 years of age. The resection was thought to be total at the time of surgery, and this impression was confirmed on postoperative imaging. Following the initial resection, the patient underwent surveillance imaging at regular intervals. Six years following the initial surgery, surveillance imaging demonstrated an enlarging area of signal abnormality at the site of the prior resection. The patient underwent a second resection with pathological confirmation of DNT recurrence. Although recurrence of DNT following resection is rare, this case suggests that surveillance imaging may have a role in patients with DNT, even following resections that are thought to be complete.
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PMID:Recurrence of dysembryoplastic neuroepithelial tumor following resection. 1855 17


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