Case Of Dysembryoplastic Neuroepithelial Tumor Research Articles

Association of CT and MRI Manifestations with Pathology in Dysembryoplastic Neuroepithelial Tumors.

To investigate the CT, MRI and pathological features of dysembryoplastic neuroepithelial tumor (DNET). The CT and MRI features of six cases of pathologically confirmed DNET were retrospectively analyzed and compared with pathology. All six cases of DNET were solitary, and lesion in one case was located in the right parietal lobe, one case in the right frontal lobe, one case in the cerebellar vermis, one case in the right temporo-parietal occipital lobe, one case in the left basal ganglia, and one case in the pineal gland. CT and MRI showed cystic solid tumor in all six cases, of which four showed calcification. In CT images, the cystic components appeared low-density, solid nodules, septa, and cyst walls were slightly high-density, and calcifications were high-density. In MRI images, the cystic components were hypointense on T1WI and hyperintense on T2WI, solid nodules, septa and cyst walls were iso-intense or slightly hyperintense on T1WI and T2WI sequences, and calcifications were all hypointense. On enhanced scan, the cystic components were not enhanced, and the solid nodules, septa, and cyst walls were inhomogeneously enhanced. The imaging manifestations of DNET are characteristic, and the combination of clinical and imaging features can greatly improve diagnostic accuracy.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy (MR-gLiTT) in Pediatric Epilepsy Surgery: State of the Art and Presentation of Giannina Gaslini Children's Hospital (Genoa, Italy) Series.

Magnetic resonance-guided laser interstitial thermal therapy (MR-gLiTT) is a novel minimally invasive treatment approach for drug-resistant focal epilepsy and brain tumors. Using thermal ablation induced by a laser diode implanted intracranially in a stereotactic manner, the technique is highly effective and safe, reducing the risk associated with more traditional open surgical approaches that could lead to increased neurological morbidity. Indications for MR-gLiTT in pediatric epilepsy surgery include hypothalamic hamartoma, tuberous sclerosis complex, cavernoma-related epilepsy, SEEG-guided seizure onset zone ablation, corpus callosotomy, periventricular nodular heterotopia, mesial temporal lobe epilepsy, and insular epilepsy. We review the available literature on the topic and present our series of patients with drug-resistant epilepsy treated by MR-gLiTT. Our experience, represented by six cases of hypothalamic hamartomas, one case of tuberous sclerosis, and one case of dysembryoplastic neuroepithelial tumor, helps to confirm that MR-gLiTT is a highly safe and effective procedure for several epilepsy conditions in children.

Surgical treatment of low-grade brain tumors associated with epilepsy.

To explore the strategy of surgical treatment of low-grade brain tumors associated with epilepsy. Clinical data of 158 patients with low-grade brain tumors were collected from January 2011 to December 2017 in Guangdong Sanjiu brain hospital. All patients received Preoperative evaluation. Lesion site: 18 cases were located in multiple cerebral lobes, 10 cases were in the functional zones, 130 cases were in the non-functional zones (including 74 cases were in the medial of temporal lobe). The surgical strategy included subtotal resection, gross-total resection and enlarged resection. Postoperative effects were evaluated by Engel classification. A total of 158 patients underwent surgical treatment, among these patients, only 1 patient underwent intracranial electrode implantation. Surgical methods: 34 cases of subtotal resection, 3 cases of gross-total resection, 119 cases of enlarged resection (including Anterior temporal lobectomy in 74 cases) and 2 case of Selective hippocampal amygdalectomy. The final pathology suggested that there are 74 cases of ganglionglioma, 25 cases of dysembryoplastic neuroepithelial tumors, 9 cases of pilocytic astrocytoma, 16 cases of oligodendroglioma, 10 cases of pleomorphic xanthoastrocytoma, 4 case of diffuse astrocytoma, 9 cases of unclassified astrocytoma, 11 case of oligoastrocytoma. The follow-up time was between 1 and 7 years, with an average of 3.44±1.77 years. Postoperative recovery: 147 patients had an Engel Class I outcome, 10 patients were in Engel Class II, 1 patient was in Class IV. The strategy of surgical treatment of low-grade brain tumors associated with epilepsy should pay more attention to the preoperative assessment of the epileptogenic zone. The tumor is not exactly the same as the epileptogenic zone, and the strategy of surgical treatment depends on the tumor feature as well as whether it was located in temporal lobe or involved in functional areas.

NIMG-01. T2WI-FLAIR MISMATCH SIGN IN LOWER GRADE GLIOMA AND DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOR

Abstract BACKGROUND T2-FLAIR mismatch sign was reported as a specific imaging marker for diffuse astrocytoma with IDH-mutant and 1p/19q non-codeletion. However, most of the previous studies for T2-FLAIR mismatch were confirmed only among lower grade glioma (LGG). The purpose of this study is to explore the T2-FLAIR mismatch sing in supratentorial non-enhancing tumor including LGG and dysembryoplastic neuroepithelial tumor (DNET) and to unveil the exception rules of the sign. METHODS Forty-four patients of non-enhancing LGG and DNET were included in this study. LGG（diffuse astrocytoma with IDH mutant (IDHmut-Noncodel), oligodendroglioma with IDH-mutant and 1p19q codeletion (IDHmut-Codel), diffuse astrocytoma with IDH wildtype (IDHwt)）and DNET were diagnosed based on WHO 2016 classification. The tumors were evaluated MRI by 2 independent reviewers to assess presence or absence of T2-FLAIR mismatch sign. CT was also performed to evaluate the localized thinning of the skull bone. Inter-reviewer agreement with Cohen’s kappa (κ) was calculated. RESULT: Ten out of 18 cases (55.6%) of IDHmut-Noncodel presented T2-FLAIR mismatch sign. None of the other LGG (IDHmut-Codel and IDHwt) presented T2-FLAIR mismatch. Eight out of 11 cases (72.7%) of DNET also present the T2-FLAIR mismatch. The overlying part of the skull bone thinning was observed in 5 cases of DNET, but none of LGG presented the localized skull bone thinning. The inter-rater agreement for the T2-FLAIR mismatch and the localized thinning of the skull bone were excellent (κ= 1.00). CONCLUSION The T2-FLAIR mismatch sign was specific marker for IDHmut-Noncodel among LGG. However, DNET also presented the T2-FLAIR mismatch sign. The localized skull bone thinning could be useful for differentiating between IDHmut-Noncodel and DNET

Surgical treatment of low grade brain tumors associated with epilepsy in children

Objective To explore the strategy of surgical treatment for children with low-grade tumors associated with epilepsy. Methods Clinical data of 30 patients with low grade tumors (ages: 1-14 years) were retrospectively reviewed who underwent surgery from January 2011 to June 2016 at Department of Neurosurgery, Guangdong Sanjiu Brain Hospital. Lesions were located in multiple cerebral lobes in 8 cases, in functional zones in 8 and in non-functional zones in 14 cases (including 10 cases with lesions in the medial temporal lobe). The surgical strategy included subtotal resection, gross-total resection and enlarged resection. Postoperative effects were evaluated by Engel classification. Results A total of 30 patients underwent surgical treatment. Subtotal resection was achieved in 8 cases, gross-total resection in 5 and enlarged resection in 17 (including 9 cases undergoing anterior temporal lobectomy and 1 case of selective amygdalohippocampectomy). The final pathology suggested that there were 11 cases of ganglioglioma, 8 cases of dysembryoplastic neuroepithelial tumor, 2 cases of pilocytic astrocytoma, 3 cases of oligodendroglioma, 3 cases of pleomorphic xanthoastrocytoma, 1 case of diffuse astrocytoma , 1 case of oligoastrocytoma and 1 case of meningioma. The follow-up duration was 1-6 years, with an average of 3.0±1.6 years. For postoperative recover: 28 cases had an outcome of Engel Class I, 1 patient was in Engel Class Ⅱ and 1 patient was in Class Ⅳ. Conclusions For surgical treatment for children with low-grade tumors associated with epilepsy, more attention should be paid to preoperative assessment of the epileptogenic zone. The tumor is not exactly the same as the epileptogenic zone and the strategy of surgical treatment depends on the tumor characteristics as well as whether it is located at temporal lobe or involved in functional areas. Key words: Epilepsy; Child; Brain neoplasms; Low grade; Neurosurgical procedures

Coexistent dysembryoplastic neuroepithelial tumour and pilocytic astrocytoma

Dysembryoplastic neuroepithelial tumour (DNET) is an uncommon mixed glioneuronal tumour. DNET is classified as Grade I neoplasm in revised World Health Organization classification of tumors of the nervous system. DNET is commonly seen in the temporal lobe of children and young adults with features of pharmacoresistant complex partial seizures. Tumors arising in association with DNETs are rare. Only two cases of pilocytic astrocytoma (PA) arising in DNETs are reported. Surgical excision is the only successful management with favourable prognosis. The development of recurrence and malignancy after subtotal or even after complete excision challenges the premise of stability and highlights the importance of close clinical follow up. Here, a case of DNET with area of PA is described which helps in understanding the pathogenesis and biological behavior of DNET.

A rare case of dysembryoplastic neuroepithelial tumor combined with encephalocraniocutaneous lipomatosis and intractable seizures.

Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous syndrome that affects ectomesodermal tissues (skin, eyes, adipose tissue, and brain). The neurologic manifestations associated with ECCL are various including seizures. However, ECCL patients very rarely develop brain tumors that originate from the neuroepithelium. This is the first described case of ECCL in combination with dysembryoplastic neuroepithelial tumor (DNET) that presented with intractable seizures. A 7-year-old girl was admitted to our center because of ECCL and associated uncontrolled seizures. She was born with right anophthalmia and lipomatosis in the right temporal area and endured right temporal lipoma excision at 3 years of age. Seizures began when she was 3 years old, but did not respond to multiple antiepileptic drugs. Brain magnetic resonance (MR) imaging performed at 8 and 10 years of age revealed an interval increase of multifocal hyperintense lesions in the basal ganglia, thalamus, cerebellum, periventricular white matter, and, especially, the right temporal area. A nodular mass near the right hippocampus demonstrated the absence of N-acetylaspartate decrease on brain MR spectroscopy and mildly increased methionine uptake on brain positron emission tomography, suggesting low-grade tumor. Twenty-four-hour video electroencephalographic monitoring also indicated seizures originating from the right temporal area. Right temporal lobectomy was performed without complications, and the nodular lesion was pathologically identified as DNET. The patient has been seizure-free for 14 months since surgery. Although ECCL-associated brain tumors are very rare, careful follow-up imaging and surgical resection is recommended for patients with intractable seizures.

Dysembryoplastic neuroepithelial tumor: A report of two cases

The dysembryoplasticneuroepithelial tumor (DNT) is an uncommon lesion characterized by a mixedpopulation of neurons, astrocytes, and oligodendroglia-like cells. It is important to be aware of this entity because it can mimic an oligodendroglioma orneurocytoma which needs more aggressive therapeutic interventions. We present two cases of DNT with unusual radiologic findings and discuss the literature review.

PRE-SURGERY MR-VISUALIZATION OF THE EPILEPTOGENIC SUPRATENTORIAL BRAIN TUMORS IN CHILDREN

Symptomatic focal epilepsies are commonly caused by the supratentorial brain tumors in chtldren. Among the 79 pediatric patients with supratentorial brain tumors 56 patients had symptomatic epilepsy (69,3%). The most epileptogenic tumors were dysembryoplastic neuroepithelial tumors (DNET), diffuse astrocytomas (DA) and gangliogliomas (GG). In all the cases of DNET and in 4 patients with GG epileptic seizures were the first manifestation, and in 4 of 5 cases of DNEO they were the only clinical sign of tumor. On the neuroimaging the MR-features of DNET, DA and GG were represented by iso- or hypointensive signal on T1 weighted image (WI) and varying in intensity from moderate to hyperintensive signal in T2 and FLAIR WI, while in cases with DNET and GG practically no mass effect and perifocal edema were seen, and on FLAIR WI the so-called "spume-like" (multicystic) structure was most clearly observed. During the follow up period no significant changes in the dimensions of identified DNET and GG were observed. In one case the combination of DNET with focal cortical dysplasia was noted. In DA it is difficult to distinguish the perifocal edema from tumorous tissue and normal brain tissue, and the growth potential of tumor is slow. The contrast enhancement of these tumors is ambiguous. Along with DNET (which is epileptogenic in 100% of cases), the most epileptogenic brain tumors are DA (in 91.7% of cases) and GG (in 80% of cases) which should be excluded in drug-resistant cases of focal epilepsy.

PTPS-13STUDY OF CLINICOPATHOLOGICAL CHARACTERISTICS, BRAF V600E MUTATION, AND MTOR SIGNALING PATHWAY ACTIVATION IN DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMORS (DNET)

Dysembryoplastic Neuroepithelial Tumor (DNET) is a WHO Grade I glioneuronal tumor of children and young adults. BRAFV600E mutation has been identified in DNETs. More recently, mTOR-pathway has been implicated in molecular pathogenesis of glioneuronal tumors. We aimed to evaluate the presence of enhanced mTOR-pathway signalling, incidence of BRAFV600E mutation, and to compare the results with clinicopathological features. Immunohistochemistry for markers of mTOR-pathway activation, viz. pS6 and p4EBP1, was performed. Sequencing for BRAFV600E mutation was done in cases with adequate tissue. Sixty-seven cases of DNET were identified, accounting for 5% of patients with drug-refractory epilepsy. Mean age of patients was 16.1 years (range: 2-38 years); male preponderance was noted. Majority (68.7%) of patients were in pediatric age group (<18 years). Duration of seizures ranged from 1-22 years (mean = 7.5 years). All patients underwent ECOG-guided resection. Histopathologically, tumors were characterized by the presence of floating neurons within a specific glioneuronal element. Associated lesions such as cortical dysplasia (19%) and mesial temporal sclerosis (1.5%) were seen. Four cases were composite lesions with DNET, ganglioglioma and cortical dysplasia. pS6 immunopositivity was seen in 91% cases, while p4EBP1 was positive in 26%. Interestingly, pS6 positivity was also seen in neurons in the adjacent dysplastic cortex. Sequencing revealed BRAF V600E mutation in 11% of cases examined. Overall seizure-free survival was 87% (n = 55). Notably, of 51 patients undergoing complete resection, 48 (94%) had good outcome (Engel grade I). All four patients who underwent incomplete resection had Engel grade II-III outcomes. Thus, DNETs are rare, surgically curable neoplasms. Identification of these tumors has prognostic as well as therapeutic implications, as most patients remain seizure-free after complete resection. Evidence of mTOR-pathway activation suggests a role for mTOR signalling in their pathogenesis, and supports the use of mTOR inhibitors in DNET patients, particularly those having persistent seizures after incomplete resection.

THE ROLE OF MAGNETIC RESONANCE IMAGING IN COMPLEX CLINICAL-EEG-IMAGING EXAMINATION OF EPILEPTOGENIC BRAIN TUMORS IN CHILDREN

Symptomatic epilepsy is common for patients with supratentorial brain tumors. Among 75 children with supratentorial brain tumors 52 patients had symptomatic epilepsy (69,3%). The most epileptogenic tumors were dysembryoplastic neuroepithelial tumors (DNET), diffuse astrocytomas (DA) and gangliogliomas (GG). In all the cases of DNET and in 4 patients with GG epileptic seizures were the first symptom, and in 4 of 5 cases of DNET seizures were the only clinical sign of tumor presence. DNET, DA and GG looked as iso- or hypointensive lumps on T1-weighted images and as moderate or hyperintensive lesions on T2-weighted and FLAIR images, without mass effect or perifocal edema in cases of DNET and GG. On FLAIR images DNET and GG have so-called “spume-like” (multicystic) structure. Follow up MRI did not reveal significant change in DNET and GG. In one case DNET was noted to be associated with focal cortical dysplasia. In DA it is difficult to distinguish the perifocal edema from tumorous tissue and normal brain tissue, and the growth potential of tumor was slow. The tumors differently cumulate contrast and interpretation of scans with contrast enhancement is ambiguous. Along with DNET (which is epileptogenic in 100% of cases), DA and GG are also epileptogenic brain tumors (seizures occur in 91.7% of cases of DA and in 80% of cases of GG) which should be excluded during diagnosis of drug-resistant focal epilepsy.

Dysembryoplastic neuroepithelial tumor with rapid recurrence of pilocytic astrocytoma component

Dysembryoplastic neuroepithelial tumor (DNT) rarely has aggressive behavior with recurrence. The authors describe a case of DNT with rapid re-growth and features of pilocytic astrocytoma. A 19-year-old girl presented with a 3-year history of complex partial seizure, which was presumably because of DNT located in the left parietal lobe. The tumor was resected, although a tiny residual lesion with cystic space enlarged with ring enhancement identified on MRI 14 days after surgery resulted in re-excision. The recurrent tumor was eventually proved to be predominantly composed of pilocytic astrocytoma. DNT is known to recur only rarely as a tumor with morphologically different components, and no cases of recurrent DNT with rapidly-growing pilocytic astrocytoma have hitherto been reported in the literature. This phenomenon may be histological "replacement" at recurrence.

Epilepsy surgery of dysembryoplastic neuroepithelial tumors using advanced multitechnologies with combined neuroimaging and electrophysiological examinations.

PurposeWe report three cases of dysembryoplastic neuroepithelial tumor (DNT) with intractable epilepsy which were successfully treated with surgery.MethodsIn all cases, technology beyond the routine workup was critical to success. Preoperative magnetic resonance imaging, 18F-fluorodeoxyglucose positron emission tomography (PET), 11C-methionine-PET, interictal electroencephalography, and intraoperative electrocorticography were utilized in all patients. In individual cases, however, additional procedures such as preoperative magnetoencephalography (Case 1), diffusion tensor fiber tractography, a neuronavigation system, and intraoperative somatosensory-evoked potential (Case 2), and fiber tractography and the neuronavigation-guided fence-post tube technique (Case 3) were instrumental.ResultsIn all the cases, the objectives of total tumor resection, resection of the epileptogenic zone, and complete postoperative seizure control and the avoidance of surgical complications were achieved.ConclusionsDysembryoplastic neuroepithelial tumor is commonly associated with medically intractable epilepsy, and surgery is frequently utilized. As DNT may arise in any supratentorial and intracortical locations within or near the critical area of the brain, meticulous surgical strategies are necessary to avoid neurological deficits. We demonstrate in the following three cases how adjunct procedures using advanced multitechnologies with neuroimaging and electrophysiological examinations may be utilized to ensure success in DNT surgery.

A Rare Case of Dysembryoplastic Neuroepithelial Tumor

We present a rare case of dysembryoplastic neuroepithelial tumor, a rare benign glioneuronal tumor of the central nervous system. It generally occurs in the supratentorial region and the temporal cerebral cortex in children and young adults. The most common presentation is epilepsy. The supratentorial tumor without any signs of mass effect or peritumoral edema is the conventionally accepted diagnostic criteria. In this case of a 19-year-old male with intractable epilepsy, atypical features such as the location of the tumor and the presence of mass effect and peritumoral edema made imaging diagnosis difficult. Diagnosis was confirmed through histopathology. Due to its recent discovery and relatively rare occurrence it is important for radiologists to recognize this disease entity.

Unusual Presentation of a Dysembryoplastic Neuroepithelial Tumor Mimicking a Pontomesencephalic Cavernous Hemangioma

Dysembryoplastic neuroepithelial tumor is a rare benign neoplasm that usually occurs in children and young adults and is characterized by intractable seizures that are refractory to medication. Since its description and inclusion in the World Health Organization classification of brain tumors, an increasing number of cases have been reported. The tumor is preferentially, but not exclusively, located in the supratentorial cortex. Rare cases of other locations have been reported. We describe the clinical, imaging and pathologic features of a case of dysembryoplastic neuroepithelial tumor arising in the pons of a 26-year-old woman, an unusual extracortical location, mimicking a cavernous hemangioma. doi: http://dx.doi.org/10.4021/jmc718w

Dysembryoplastic neuroepithelial tumour: A case report

Aim and Objective: Dysembryoplastic neuroepithelial tumour is an unusual brain tumour with varied incidence commonly occured in younger age group. We report a 16-year old female diagnosed as a case of dysembryoplastic neuroepithelial tumour. Clinical presentation: A 16 year old female was examined for headache and convulsion for two months. MRI revealed a brain tumour which was later confirmed as dysembyroplastic neuroepithelial tumour by histopathological examination.DOI: http://dx.doi.org/10.3329/pulse.v4i1.6968Pulse Vol.4 January 2010 p.43-44

A cortical dysembryoplastic neuroepithelial tumor initially occurring in the periventricular white matter

In this report, a rare case of dysembryoplastic neuroepithelial tumor (DNET) initially presented as a small white matter lesion with calcification adjacent to the lateral ventricle and extending to the frontal cortex after 7 years. This 1-year-old boy initially suffered from partial seizures. Initial CT revealed a small, low-density area surrounding a tiny calcified mass in the deep white matter of the left frontal lobe. Seven years later, his seizures had become intractable to antiepileptic agents, and MR imaging demonstrated a relatively large mass extending from the calcified lesion up to the adjacent cortical surface. He underwent surgery and the tumor was subtotally removed. Histological examination of the tumor verified it as a DNET consisting of clusters of small oligodendrocytes with floating neurons in the mucoid background. The pattern of the tumor progression in this case suggests that a DNET in the cortex originates from the subependymal germinal layer near the ventricle.

Clinicopathologic features of recurrent dysembryoplastic neuroepithelial tumor and rare malignant transformation: a report of 5 cases and review of the literature

Dysembryoplastic neuroepithelial tumors (DNETs) have traditionally been viewed as benign "quasihamartomatous" tumors widely considered curable with surgery alone. More recently, case reports have described malignant gliomas arising after irradiation and recurrences following subtotal or even gross total resection. Herein, we describe five cases of DNET with recurrences 2-7 years after resection. Although the radiology was often alarming (e.g., new ring enhancing mass), the pathology remained benign in most cases. Nonetheless, a probably radiation induced anaplastic astrocytoma was encountered in one case 7 years after therapy. These findings suggest that these patients may need closer follow-up than initially suggested, lending further support to the notion that this tumor behaves more like a benign neoplasm, rather than a dysplastic or hamartomatous lesion.

Different pattern of expression of nestin in the non-specific form of dysembryoplastic neuroepithelial tumors compared to the simple and complex forms

Dysembryoplastic neuroepithelial tumors (DNTs) are benign glial-neuronal neoplasms with characteristic cliniopathologic features. Three histologic forms of DNTs have been described (simple, complex, and non-specific). The developmental origin of the tumors remains controversial. To determine the developmental origin and nature of the histologic forms of DNTs, immunohistochemical studies of nestin, TrkA, TrkB, p75, and NeuN were conducted in 40 cases of DNTs, including 11, 9, and 20 simple, complex, and non-specific forms, respectively. Nestin positivity of oligodendroglia-like cells (OLCs) was present in 50 and 27.3% of simple and complex forms, respectively. In the non-specific form of DNT, 94.7% of the cases were positive for nestin. Most DNTs exhibited diffuse, strong staining for TrkA and TrkB, irrespective of the histologic subtypes. Both p75 and NeuN positivity were found in about one-half of the simple, complex, and non-specific forms, respectively. Our study suggests that OLCs are a heterogeneous population of cells, and higher expression of nestin in the non-specific form of DNTs compared to the simple or complex forms suggests that the non-specific form has an earlier developmental origin than the simple or complex forms.

Dysembryoplastic Neuroepithelial Tumor of the Brainstem

Dysembryoplastic neuroepithelial tumor (DNT) is a clinically benign stable lesion, most frequently located in the temporal and frontal lobes, often responsible for epilepsy in young adults. We describe an unusual case of DNT in the brainstem of a 45-year-old woman. Brain MRI showed a multicystic-like lesion localized in the left inferior pons, involving the ipsilateral cerebellar peduncle and partially dislocating the fourth ventricle. The specific pattern of MRI and CT appearance of DNT and its benign course (our patient is clinically stable with unchanged MRI images at two year follow-up) may help differentiate this tumor from other lesions, i.e. gangliogliomas and glioneural malformations.