UNLABELLEDOBJECTIVE To study the clinicopathologic features, radiologic findings, treatment modalities and prognosis of dysembryoplastic neuroepithelial tumor (DNT).

METHODSThe clinical features, histopathologic findings, immunohistochemistry and electron microscopy of 18 cases of DNT were analyzed. Results Among the 18 cases studied, 14 were males and 4 females. The age of these patients ranged from 3 to 46 (mean age = 22. 8 years). Partial seizure was the main presenting symptom in all patients. The history of epilepsy could be as long as 17 years. On magnetic resonance imaging (MRI) study, the tumor was hypodense on T1 and hyperdense on T2. There was neither edema nor mass effect. All but 2 cases were supratentorial and intracortical in location. Ten cases were treated by complete surgical excision and the remaining 8 tumors were partially excised. In the 14 patients with follow-up data available, 13 survived for 1.4 to 11 years after the operation (with more than 10 years survival observed in 2 patients). The average survival period was 5.5 years. None of the cases showed tumor recurrence after operation. Histologically, all tumors demonstrated a multinodular architecture and were intracortical in location, sometimes with extension into the white matter. The characteristic "glioneuronal constituent" was an essential feature for making the diagnosis of DNT. The tumor was formed by an admixture of oligodendrocyte-like cells, mature neurons and astrocytes, with obvious microcystic changes. These neurons were often dispersed singly in the mucoid matrix. In most cases, the foci of cortical dysplasia were found in adjacent areas. Immunohistochemical study demonstrated positivity for synaptophysin, neurofilament and S-100 protein in the neurons and some oligodendrocyte-like cells. The staining of glial fibrillary acidic protein in the oligodendrocyte-like cells was negative. Electron microscopy showed early neuronal, astrocytic and oligodendroglial differentiation of the oligodendrocyte-like cells.

CONCLUSIONSDNT is a benign tumor (corresponding to WHO grade I) that can be cured by surgical excision, despite sometimes incomplete tumor removal. A correct diagnosis of this entity requires thorough understanding of the clinical, radiologic, histologic and immunohistochemical features.

Adolescent ; Adult ; Brain Neoplasms ; metabolism ; pathology ; surgery ; Cerebral Cortex ; pathology ; surgery ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Neoplasms, Neuroepithelial ; metabolism ; pathology ; surgery ; Neurofilament Proteins ; metabolism ; Oligodendroglia ; pathology ; ultrastructure ; S100 Proteins ; metabolism ; Survival Rate ; Synaptophysin ; metabolism

OBJECTIVETo study the clinicopathologic features and radiologic findings of dysembryoplastic neuroepithelial tumor (DNT).

METHODSThe clinical presentations, radiologic findings, histologic features and immunophenotype of 9 cases of DNT were analyzed.

RESULTSThe age of patients ranged from 12 to 51 years (mean age = 32 years). Most presented with partial seizures, sometimes accompanied by transient aphasia, agraphia and decreased visual acuity. One case was asymptomatic and discovered incidentally during a routine check-up. All patients had no neurological deficit found on physical examination. All tumors were located in the supratentorial cerebral cortex. There was no peritumoral edema or space-occupying effect on radiologic examination. The tumors involved either frontal lobe (number = 4), temporal lobe (number = 4), frontoparietal lobe (number = 1) . Two cases showed cystic changes. Two histologic variants of DNT were recognized: simple (number = 3) and complex (number = 6). Simple variant was composed mainly of the glioneuronal element, accompanied by surrounding oligodendrocyte-like cells, and the complex variant contained a low-grade glioma component, in addition to the glioneuronal element and sometimes foci of cortical dysplasia.

CONCLUSIONSDNT is a benign tumor with excellent prognosis after surgical excision. Local recurrence is rare. Complex variant of DNT needs to be distinguished from other types of low-grade glioma.

Adolescent ; Adult ; Brain Neoplasms ; complications ; metabolism ; pathology ; surgery ; Cerebral Cortex ; metabolism ; pathology ; Child ; Child, Preschool ; Epilepsies, Partial ; etiology ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neuroectodermal Tumors, Primitive ; complications ; metabolism ; pathology ; surgery ; Neurofilament Proteins ; metabolism ; Oligodendroglia ; pathology ; ultrastructure ; S100 Proteins ; metabolism ; Survival Rate ; Synaptophysin ; metabolism

This study describes the neuropathologic features of normal canine brain ablated with non-thermal irreversible electroporation (N-TIRE). The parietal cerebral cortices of four dogs were treated with N-TIRE using a dose-escalation protocol with an additional dog receiving sham treatment. Animals were allowed to recover following N-TIRE ablation and the effects of treatment were monitored with clinical and magnetic resonance imaging examinations. Brains were subjected to histopathologic and ultrastructural assessment along with Bcl-2, caspase-3, and caspase-9 immunohistochemical staining following sacrifice 72 h post-treatment. Adverse clinical effects of N-TIRE were only observed in the dog treated at the upper energy tier. MRI and neuropathologic examinations indicated that N-TIRE ablation resulted in focal regions of severe cytoarchitectural and blood-brain-barrier disruption. Lesion size correlated to the intensity of the applied electrical field. N-TIRE-induced lesions were characterized by parenchymal necrosis and hemorrhage; however, large blood vessels were preserved. A transition zone containing parenchymal edema, perivascular inflammatory cuffs, and reactive gliosis was interspersed between the necrotic focus and normal neuropil. Apoptotic labeling indices were not different between the N-TIRE-treated and control brains. This study identified N-TIRE pulse parameters that can be used to safely create circumscribed foci of brain necrosis while selectively preserving major vascular structures.
Animals ; Brain/metabolism/*pathology/surgery/ultrastructure ; Caspase 3/metabolism ; Caspase 9/metabolism ; Dogs ; Electroporation/veterinary ; Magnetic Resonance Imaging/methods ; Microscopy, Electron, Transmission ; Necrosis/metabolism/pathology ; Neurosurgical Procedures/*adverse effects