Dysembryoplastic Neuroectodermal Tumor: An Analysis from the Surveillance, Epidemiology, and End Results Program, 2004–2013

Atypical presentation of dysembryoplastic neuroepithelial tumor in an adult without epilepsy: a case report

Aim of the study: Dysembryoplastic neuroepithelial tumor (DNET) is a rare glioneuronal tumor usually found in the temporal lobe of children and young adults. DNETs are commonly associated with drug-resistant partial seizures, with most cases diagnosed before age 20. Asymptomatic brain tumors are rare in the general healthy population, and the frequency of incidental DNETs in adults remains unknown.Materials and methods: We report the case of a 34-year-old healthy man who presented with a facial rash but was incidentally found to have a large T1 hypointense lesion in the left temporal cortex on neuroimaging. The patient opted for surgical removal of the mass, which was subsequently identified as a DNET, positive for a fibroblast growth factor receptor (FGFR) mutation.Results: This case report presents the first incidentally discovered DNET in an adult without epilepsy, highlighting its atypical presentation. In addition, the presence of an FGFR mutation emphasizes its role in DNET pathogenesis and potential therapeutic implications. DNETs exhibit varied behavior based on age, tumor location, and cortical dysplasia.Conclusions: In this case, the absence of seizure onset may be attributed to the lack of cortical dysplasia. Further research is needed to understand the incidence of DNETs and their association with seizure onset and cortical dysplasia.

[Disseminated ependymal dysembryoplastic neuroepithelial tumor: a case report and literature review]

Dysembryoplastic neuroepithelial tumor (DNET) is a benign mixed neuronal-glial neoplasm (WHO grade 1). DNET is most often localized in temporal lobes and found in children and young people with epilepsy. There a few cases of DNET in ventricular system with dissemination along the ependyma in the world literature.

MATERIAL AND METHODS

We present a rare case of T1- and T2-negative ventricular system tumor. Only FIESTA imaging revealed dissemination with multiple focal lesions of the third ventricle, its bottom and lateral walls, anterior horns of lateral ventricles, cerebellar vermis, cervical and lumbar spinal cord.

RESULTS

The patient underwent transcortical endoscopic biopsy of the third ventricle tumor with simultaneous ventriculoperitoneal shunting. DNET was diagnosed, and radiotherapy was subsequently performed. Literature data on this issue were analyzed.

CONCLUSION

To date, disseminated forms of DNET are extremely rare. X-ray features and morphological results allow us to establish the correct diagnosis and determine further treatment strategy.

Pediatric and elderly polymorphous low-grade neuroepithelial tumor of the young: Typical and unusual case reports and literature review

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY), one of the pediatric-type diffuse low-grade gliomas, is characterized by a diffuse infiltrating pattern of oligodendroglioma-like tumor cells showing CD34 positivity and harbors mitogen-activated protein kinase (MAPK) alteration, such as vRAF murine sarcoma viral oncogene homolog B1 (BRAF) p.V600E or fibroblast growth factor fusion genetically. It occurs mainly in pediatric and adolescents with seizures due to the dominant location of the temporal lobe. However, there have been a few cases of PLNTY in adult patients, suggesting the wide range of this tumor spectrum. Here, we describe two cases of PLNTY, one in a 14-year-old female and the other in a 66-year-old female. The pediatric tumor showed typical clinical course and histopathology with BRAF p.V600E mutation, whereas the elderly tumor was unusual because of non-epileptic onset clinically and ependymal differentiation histopathologically harboring KIAA1549-BRAF fusion. There might be unusual but possible PLNTY, as in our elderly case. We also compared typical pediatric and unusual elderly tumors by reviewing the literature.

Genomic analysis as a tool to infer disparate phylogenetic origins of dysembryoplastic neuroepithelial tumors and their satellite lesions

Dysembryoplastic neuroepithelial tumor (DNET) is a low-grade brain tumor commonly associated with drug-resistant epilepsy. About half of DNETs are accompanied by tiny nodular lesions separated from the main mass. The existence of these satellite lesions (SLs) has shown a strong association with tumor recurrence, suggesting that they are true tumors. However, it is not known whether SLs represent multiple foci of progenitor tumor cell extension and migration or a multifocal development of the main DNET. This study was designed to elucidate the histopathology and pathogenesis of SLs in DNETs. Separate biopsies from the main masses and SLs with DNET were analyzed. We performed comparative lesion sequencing and phylogenetic analysis. FGFR1 K656E and K655I mutations or duplication of the tyrosine kinase domain was found in all 3 DNET patients and the main masses and their SLs shared the same FGFR1 alterations. The phylogenic analysis revealed that the SLs developed independently from their main masses. It is possible that the main mass and its SLs were separated at an early stage in oncogenesis with shared FGFR1 alterations, and then they further expanded in different places. SLs of DNET are true tumors sharing pathogenic mutations with the main masses. It is plausible that multifocal tumor development takes place in the dysplastic cortex containing cells with a pathogenic genetic alteration.

Long-Term Seizure Outcomes and Predictors in Patients with Dysembryoplastic Neuroepithelial Tumors Associated with Epilepsy

OBJECTIVE

To determine the predictors and the long-term outcomes of patients with seizures following surgery for dysembryoplastic neuroepithelial tumors (DNTs); Methods: Clinical data were collected from medical records of consecutive patients of the Department of Neurosurgery of Sanbo Brain Hospital of Capital Medical University with a pathological diagnosis of DNT and who underwent surgery from January 2008 to July 2021. All patients were followed up after surgery for at least one year. We estimated the cumulative rate of seizure recurrence-free and generated survival curves. A log-rank (Mantel-Cox) test and a Cox proportional hazard model were performed for univariate and multivariate analysis to analyze influential predictors; Results: 63 patients (33 males and 30 females) were included in this study. At the final follow-up, 49 patients (77.8%) were seizure-free. The cumulative rate of seizure recurrence-free was 82.5% (95% confidence interval (CI) 71.8-91.3%), 79.0% (95% CI 67.8-88.6%) and 76.5% (95% CI 64.8-87.0%) at 2, 5, and 10 years, respectively. The mean time for seizure recurrence-free was 6.892 ± 0.501 years (95% CI 5.91-7.87). Gross total removal of the tumor and a short epilepsy duration were significant predictors of seizure freedom. Younger age of seizure onset, bilateral interictal epileptiform discharges, and MRI type 3 tumors were risk factors for poor prognosis; Conclusions: A favorable long-term seizure outcome was observed for patients with DNT after surgical resection. Predictor analysis could effectively guide the clinical work and evaluate the prognosis of patients with DNT associated with epilepsy.

The genomic landscape of dysembryoplastic neuroepithelial tumours and a comprehensive analysis of recurrent cases

AIMS

Dysembryoplastic neuroepithelial tumour (DNT) is a glioneuronal tumour that is challenging to diagnose, with a wide spectrum of histological features. Three histopathological patterns have been described: specific DNTs (both the simple form and the complex form) comprising the specific glioneuronal element, and also the non-specific/diffuse form which lacks it, and has unclear phenotype-genotype correlations with numerous differential diagnoses.

METHODS

We used targeted methods (immunohistochemistry, fluorescence in situ hybridisation and targeted sequencing) and large-scale genomic methodologies including DNA methylation profiling to perform an integrative analysis to better characterise a large retrospective cohort of 82 DNTs, enriched for tumours that showed progression on imaging.

RESULTS

We confirmed that specific DNTs are characterised by a single driver event with a high frequency of FGFR1 variants. However, a subset of DNA methylation-confirmed DNTs harbour alternative genomic alterations to FGFR1 duplication/mutation. We also demonstrated that a subset of DNTs sharing the same FGFR1 alterations can show in situ progression. In contrast to the specific forms, "non-specific/diffuse DNTs" corresponded to a heterogeneous molecular group encompassing diverse, newly-described, molecularly distinct entities.

CONCLUSIONS

Specific DNT is a homogeneous group of tumours sharing characteristics of paediatric low-grade gliomas: a quiet genome with a recurrent genomic alteration in the RAS-MAPK signalling pathway, a distinct DNA methylation profile and a good prognosis but showing progression in some cases. The "non-specific/diffuse DNTs" subgroup encompasses various recently described histomolecular entities, such as PLNTY and diffuse astrocytoma, MYB or MYBL1 altered.

A Constellation of Atypical Findings in a Nine-Year-Old Child With Dysembryoplastic Neuroepithelial Tumors: A Case Report and Review of the Literature

Dysembryoplastic neuroepithelial tumors (DNETs) are rare, generally benign, mixed neuronal-glial neoplasms occurring most often between 10 and 14 years of age. These lesions are classically cortically based and solitary, found preferentially in the temporal lobe, and most commonly present with seizures. On magnetic resonance imaging (MRI), these lesions are generally cystic and have variable contrast enhancement, which, when present, often involves the periphery. Rarely, lesions followed radiographically may demonstrate delayed contrast enhancement. Here, we present a case of multifocal DNETs involving the cerebellum that demonstrated delayed contrast enhancement. In addition, these occurred in a patient with Noonan syndrome (NS), a “RASopathy” disorder associated with low-grade glial and glioneuronal tumors. We present a summary of all previously reported cases of cerebellar DNETs. Our patient was successfully treated surgically and is doing well clinically, now one year status post his last procedure, and is being closely monitored with serial MRIs for progression. Gross total resection is often curative without adjuvant therapy for most DNETs. Our case emphasizes the importance of radiographic surveillance, as multifocality and recurrence may necessitate more than one procedure. Lastly, clinicians should be suspicious for DNETs and other low-grade glial tumors when treating patients with NS, acknowledging their predisposition for multifocal involvement and atypical presentations.

From a dysembryoplastic neuroepithelial tumor to a glioblastoma multiforme: Pitfalls of initial diagnosis on biopsy material, a case report

Background:

Ganglioglioma (GG) and dysembryoplastic neuroepithelial tumor (DNET) belong to the group of low-grade epilepsy-associated tumors (LEAT) and are the most prevalent tumor types found in patients undergoing epilepsy surgery. Histopathological differentiation between GG and DNET can be difficult on biopsies due to limited tumor tissue.

Case Description:

Here, we present a rare case where a low-grade tumor was initially classified as DNET, based on biopsy findings and unfortunately dedifferentiated within 10 years into a glioblastoma multiforme. After gross total resection, the initial tumor was reclassified as GG.

Conclusion:

This case illustrates the diagnostic challenges of LEAT, especially on biopsy material. Therefore, we advocate to counsel for complete resection and histopathological diagnosis utilizing tumor markers to confirm the nature of the tumor and to advice type of follow-up and eventual concurrent treatment.

Surgical resection of dysembryoplatic neuroepithelioma tumor associated with epilepsy based on imaging classification

OBJECTIVE

Dysembryoplastic neuroepithelioma tumors (DNETs) are rare glioneuronal tumors usually present with partial epilepsy. We analyzed the surgical curative effect of DNETs based on imaging classification.

METHODS

The clinical, neuroimaging, seizure history, neuropathological data, and other medical records of 21 cases of cerebral hemisphere DNETs were collected and analyzed retrospectively. According to the magnetic resonance imaging (MRI) classification of Chassoux, these cases were divided into 8 cases of type I (thylakoid type), 6 cases of type II (nodular type), and 7 cases of type III (dysplasia). All patients received detailed preoperative evaluation and underwent surgical treatment. We statistically compared the postoperative seizure outcome of different DNET MRI types by Engel classification.

RESULTS

All tumors were surgically removed and pathologically diagnosed as DNETs. The follow-up period was 5-68 months Engel class I outcome was achieved in all type I cases, 3 (50%) type II cases, and 3 (42.9%) type III cases. The postoperative seizure outcome of MRI type I was better than that of type II and III.

CONCLUSION

Based on the MRI classification of DNET by Chassoux, the postoperative epilepsy control of type I is better than that of type II and type III, which may be related to the residual FCD around the tumor of type II and type III. Thus, the MRI classification of DNET can contribute to the preoperative design of the resection plan. Total resection of type I and extended resection of type II, as well as type III, will help to improve the postoperative seizure-free rate in DNET.

Neuropathology of Surgically Managed Epilepsy Specimens

Epilepsy is characterized as recurrent seizures, and it is one of the most prevalent disorders of the human nervous system. A large and diverse profile of different syndromes and conditions can cause perturbations in neural networks that are associated with epilepsy. Advances in neuroimaging and electrophysiological monitoring have enhanced our ability to localize the neuropathological lesions that alter the neural networks giving rise to epilepsy, whereas advances in surgical management have resulted in excellent seizure control in many patients following resections. Histopathologic study using a variety of special stains, molecular analysis, and functional studies of these resected tissues has facilitated the neuropathological characterization of these lesions. Here, we review the neuropathology of common structural lesions that cause epilepsy and are amenable to neurosurgical resection, such as hippocampal sclerosis, focal cortical dysplasia, and its associated principal lesions, including long-term epilepsy-associated tumors, as well as other malformations of cortical development and Rasmussen encephalitis.

Dysembryoplastic neuroepithelial tumor presenting as a hypothalamic hamartoma in a child with gelastic seizures: case report

Dysembryoplastic neuroepithelial tumors (DNETs) are benign intracranial tumors of neuroglial origin, mostly located in the supratentorial regions and particularly in the temporal lobe. Few cases of DNETs in the hypothalamus have been described. The authors present the case of a DNET in the hypothalamus. The 5-year-old girl with complaints of limb and gelastic seizures was admitted to the neurosurgical department of Xiangya Hospital. Neurological examination findings were unremarkable. MRI showed isointensity without significant enhancement on T1- and T2-weighted images. The lesion exhibited clearly defined borders on the sagittal, coronal, and axial images. The preliminary diagnosis was hypothalamic hamartoma (HH); however, the lesion was surgically removed, and histopathological examination confirmed the diagnosis of a DNET. Hypothalamic DNETs are extremely rare. Based on their clinical manifestation and imaging, DNETs are easily misdiagnosed as HHs. Diagnoses apart from HHs must be entertained when a hypothalamic lesion is being investigated.

Pediatric septal dysembryoplastic neuroepithelial tumor (sDNT): case-based update

PURPOSE

The purpose of this study was to review a case of a septal dysembryoplastic neuroepithelial tumor (sDNT) and compare it to cases reported in the current literature.

METHODS

We review a case of sDNT and compare with 7 other previously noted cases in the literature.

RESULTS

The mainstay treatment is gross total resection, and most patients achieve full clinical resolution. Septal dysembryoplastic neuroepithelial tumor (sDNT) is a rare pediatric disease most commonly presenting as intractable epilepsy or headache. sDNT has been recognized as a genotypically distinct entity from DNT. A high frequency (~ 80%) of mutations of platelet-derived growth factor receptor A (PDGFRA) has been isolated in sDNT and could form the basis for future therapy. MRI is most commonly used to radiographically diagnose the disease and usually demonstrates a lobular interventricular mass involving the septum, potentially extending to the third ventricle.

CONCLUSIONS

Our case and literature review validates endoscopic biopsy as a diagnostic and therapeutic intervention.

[Surgical treatment of epilepsy in children with gloneuronal brain tumors: morphology, MRI semiology and factors affecting the outcome]

INTRODUCTION

Glioneuronal tumors (GNT) are usually found in children (less than 1.5% of all neoplasms of the brain). With rare exceptions, they are benign and usually manifest only by epilepsy, which is quite often resistant to treatment with AE drugs. Tumor removal usually helps to cope with epileptic seizures, however, a number of issues regarding diagnosis and surgical treatment (interpretation of morphological data and classification, epileptogenesis and topography of the epileptogenic zone, the value of intraoperative invasive EEG and the optimal volume of resection) remain debatable.

AIM

To describe the morphology, electro-clinical picture and MR-semiology in patients with gloneuronal brain tumors, as well as to analyse the results of their surgical treatment and the factors determining its outcome.

MATERIAL AND METHODS

152 children with a median age of 8 years were treated surgically (There were 64 gangliogliomas, 73 DNT, 15 cases where the tumor classification failed - GNT NOS). In children under 2 years of age, temporal localization of the tumor prevailed. In 81 cases, ECoG was used during the operation. Surgical treatment complications: transient neurological deficit (in 15 cases); hematomas removed without consequences (in 2 cases), infectious (osteomyelitis of bone bone flap in 2 cases). We analyzed: the age of the epilepsy onset (median - 4 years 7 months) and its duration (median - 23.5 months), the type of seizures, as well as the features of MR-semiology and morphology of tumors and adjacent areas of the brain. The volume of tumor resection was verified by MRI (in 101 cases) and CT (in each case). The follow-up was collected through face-to-face meetings, with repeated video EEG and MRI, as well as telephone interviews. We studied the effect of a number of parameters characterizing the patient and features of his/her operation on the outcome of treatmen.

RESULTS

Among 102 patients in whom the follow-up history is one year or more (median - 2 years), a favorable outcome (Engel IA) was observed in 86 of them (84%); 55 of them (54%) at the time of the last examination stopped drug AE treatment. Radical tumor removal and younger age at the time of surgery were statistically significantly associated with a favorable result.

CONCLUSION

In children with gloneuronal brain tumors, removal of the tumor is effective and relatively safe in the treatment of symptomatic epilepsy. Radical tumor resection and earlier intervention are the most important prerequisites for a favorable outcome and persistent remission of seizures.

Low-grade developmental and epilepsy associated brain tumors: a critical update 2020

Brain tumors represent the second most frequent etiology in patients with focal seizure onset before 18 years of age and submitted to epilepsy surgery. Hence, this category of brain tumors, herein defined as low-grade, developmental, epilepsy-associated brain tumors (LEAT) is different from those frequently encountered in adults as (A): 77% of LEAT occur in the temporal lobe; (B): the vast majority of LEAT are of low malignancy and classified as WHO I°; (C): LEAT are often composed of mixed glial and neuronal cell components and present with variable growth patterns including small cysts or nodules; (D): LEAT do not share common gene driving mutations, such as IDH1 or 1p/19q co-deletions. Characteristic entities comprise the ganglioglioma (GG), the dysembryoplastic neuroepithelial tumor (DNT), the angiocentric glioma (AG), the isomorphic diffuse glioma (IDG) and the papillary glio-neuronal tumor (PGNT), representing 73.2% of 1680 tumors collected in a large German series of 6747 patients submitted to epilepsy surgery. In the realm of exciting discoveries of genetic drivers of brain tumors new genes have been also reported for LEAT. BRAF V600E mutations were linked to GG with CD34 expression, FGFR1 mutations to DNT, MYB alterations to AG and also IDG and PRKCA fusions to PGNT, suggesting the possibility to also develop a genetically driven tumor classification scheme for LEAT. Rare availability of LEAT in a single center is a challenging obstacle, however, to systematically unravel the neurobiological nature and clinical behavior of LEAT. Other challenges in need of clarification include malignant tumor progression of LEAT entities, seizure relapse in patients following bulk tumor resection and the controversial issue of associated focal cortical dysplasia as additional pathomechanism. In order to advance our understanding and promote reliable diagnostic work-up of LEAT, we recommend, therefore, international collaboration to achieve our goals.

A Multi-Institutional Analysis of Factors Influencing Surgical Outcomes for Patients with Newly Diagnosed Grade I Gliomas

OBJECTIVE

To assess the impact of intraoperative magnetic resonance imaging (iMRI), extent of resection (EOR), and other factors on overall survival (OS) and progression-free survival (PFS) for patients with newly diagnosed grade I gliomas.

METHODS

A multicenter database was queried to identify patients with grade I gliomas. Retrospective analyses assessed the impact of patient, treatment, and tumor characteristics on OS and PFS.

RESULTS

A total of 284 patients underwent treatment for grade I gliomas, including 248 resections (205 with iMRI, 43 without), 23 biopsies, and 13 laser interstitial thermal therapy treatments. Log-rank analyses of Kaplan-Meier plots showed improved 5-year OS (P = 0.0107) and PFS (P = 0.0009) with increasing EOR, and a trend toward improved 5-year OS for patients with lower American Society of Anesthesiologists score (P = 0.0528). Greater EOR was associated with significantly increased 5-year PFS for pilocytic astrocytoma (P < 0.0001), but not for ganglioglioma (P = 0.10) or dysembryoplastic neuroepithelial tumor (P = 0.57). Temporal tumors (P = 0.04) and location of "other" (P = 0.04) were associated with improved PFS, and occipital/parietal tumors (P = 0.02) were associated with decreased PFS compared with all other locations. Additional tumor resection was performed after iMRI in 49.7% of cases using iMRI, which produced gross total resection in 64% of these additional resection cases.

CONCLUSIONS

Patients with grade I gliomas have extended OS and PFS, which correlates positively with increasing EOR, especially for patients with pilocytic astrocytoma. iMRI may increase EOR, indicated by the rate of gross total resection after iMRI use but was not independently associated with increased OS or PFS.

Gliomas: survival differences between metropolitan and non-metropolitan counties

BACKGROUND

For gliomas, metropolitan status has not been heavily explored in the context of short-term mortality or long-term observed survival. Larger populations are associated with proximity to academic universities/high-volume hospitals.

METHODS

The SEER-18 registry was queried for patients with gliomas. The patients were further classified into two population groups based on rural-urban continuum codes: metropolitan or non-metropolitan. Demographics and clinical factors were compared between both groups. For observed survival, univariate and multivariate analyses occurred with Cox proportional hazards model.

RESULTS

The non-metropolitan group constituted approximately 10.8% of all patients. Age at diagnosis of glioma was older for the non-metropolitan group compared to metropolitan group (51.60 years vs. 49.06 years). Relative to the metropolitan group, the non-metropolitan group exhibited a larger proportion of Caucasian, married, grade I and IV gliomas, no surgery, no GTR (for those who had surgery), and temporal/parietal/occipital locations. Other covariates (sex, tumor size, laterality, and radiation status) did not exhibit significant differences in proportions. From analysis of observed survival, independent predictors include population group, as well as age, gender, marital status, tumor location, tumor grade, laterality, GTR, and receipt of radiation. Short-term mortality was 11.68% and 13.04% for Metropolitan and non-metropolitan groups, respectively. Median survival was 15 months and 12 months for Metropolitan and non-metropolitan groups, respectively.

CONCLUSIONS

About one-tenth of gliomas are treated at non-metropolitan sites. Key differences exist among patient/glioma characteristics based on metropolitan status. Overall, metropolitan status appears to influence short-term mortality and long-term observed survival for gliomas.

Causes of death in glioblastoma: insights from the SEER database

BACKGROUND

Glioblastoma (GB) and its variants portend a poor prognosis. The predominant cause of death (COD) is related to the cancer diagnosis, but a significant subset is related to other causes. As GB is a systemic disease requiring systemic treatment, focus regarding all COD provides a comprehensive illustration of the disease.

METHODS

The SEER-18 was queried for patients with cranial GB and its variants. Age, gender, race, marital status, tumor characteristics, treatment details, and follow-up data were acquired. The patients were classified into group A (death attributed to this cancer diagnosis) or group B (death attributed to causes other than this cancer diagnosis).

RESULTS

From 1973 to 2013, 36,632 deaths (94%) constituted group A, and 2,324 deaths (5.9%) constituted group B. The latter significantly exhibited lower proportions of age <60, Caucasians, married status, frontal/brain stem/ventricle tumor locations, and receipt of radiation. From logistic regression, age >60, male gender, race, not married, tumor location, and no radiation were significant independent predictors for group B. The top known CODs in group B are diseases of heart, pneumonia and influenza, cerebrovascular diseases, accidents and adverse effects, and infections.

CONCLUSIONS

CODs not attributed to GB remains a significant subset of all CODs. Many of these, particularly diseases of heart, are frequent comorbidities. Moreover, infection-related CODs after GB diagnosis appear more salient compared to CODs in the general population. Consideration of these CODs, and vigilant treatment aimed at these CODs, may improve overall care for GB patients.

Dysembryoplastic Neuroepithelial Tumors: What You Need to Know

OBJECTIVE

An updated and comprehensive review on dysembryoplastic neuroepithelial tumor (DNET) focusing on differential diagnosis, atypical presentation, seizure outcome, and risk of malignant transformation.

METHODS

A PubMed/MEDLINE-based literature search has been performed using "dysembryoplastic neuroepithelial tumor" as a keyword. Two treated cases characterized by an atypical presentation have been reviewed.

RESULTS

Of 1162 articles, 200 relevant studies have been selected. DNET is a benign mixed neuronal-glial tumor causing drug-resistant epilepsy primarily in children and young adults. The typical radiological pattern is a magnetic resonance imaging (MRI) T1-hypointense, T2-, and fluid-attenuated inversion-recovery hyperintense multicystic lesion involving the cerebral cortex with no edema. Contrast enhancement may be present and a focal cortical dysplasia is commonly associated with it. MRI diffusion, perfusion, and spectroscopy have a paramount role in the differential diagnosis. The "specific glioneuronal elements" are pathognomonic. They are positive for S100 protein, synaptofisin, neuronal nuclei, oligodendrocyte transcription factor, neurite outgrowth inhibitor, and microtubule-associated protein 2, but negative for glial fibrillary acidic protein. As opposed to v-myb avian myeloblastosis viral oncogene homolog, isocitrate dehydrogenase-1/isocitrate dehydrogenase-2 mutation and codeletion 1p-19q, fibroblast growth factor receptor 1 and BRAF V600E mutations are present. The effectiveness of surgery on seizure outcome has been established. Rare malignant transformations have been reported, especially in extra-temporal and complex forms.

CONCLUSIONS

Advanced MRI techniques are fundamental in the differential diagnosis for DNET versus other low-grade gliomas. Immuno-phenotype assessment and search for fibroblast growth factor receptor 1 and BRAF V600E mutations limit the risk of misdiagnoses. A gross total tumor removal is generally associated with a seizure-free outcome. Recurrences and malignant transformations may rarely follow, legitimizing MRI surveillance in cases of subtotal tumor resection.

Glioblastoma in the setting of prior lower grade gliomas - insights from SEER database

Introduction

Secondary glioblastomas (GBs) constitute a small subset of all GBs and tend to arise after a lower grade glioma. Though knowledge regarding this subset has gained traction in recent years, its definition continues to evolve, complicating its clinical management. Investigation of epidemiology and survival patterns may help provide needed insights.

Results

The age at GB diagnosis is significantly lower (46.22 vs 60.25 years) for group B. The distribution among type of GB (glioblastoma, giant cell glioblastoma, or gliosarcoma) was significantly different, with no diagnosis of giant cell GB in Group B. Compared to Group A, Group B exhibited a higher proportion of females, not married, smaller tumors, no GTR, and no radiation (all p < 0.05). GB-related observed survivals were comparable. Cox regression with inclusion of co-variates reveal no significant influence of GB group on observed survival. Regarding group B, mean age was 40.197 for diagnosis of initial lower grade glioma. The most common initial ICD-O-3 pathology was oligodendroglioma, NOS; astrocytoma, NOS; astrocytoma, anaplastic; and mixed glioma.

Methods

The SEER-18 registry was queried for patients with GBs. Patients were further classified into two GB groups: Group A – those with GB as the only primary tumor, and Group B – those with GB as a 2^nd primary or subsequent tumor and with history of lower grade gliomas. Demographics and clinical factors were compared between group A and B. Appropriate statistics were employed to calculate incidences and differences among factors and GB-related survivals between the groups.

Conclusions

Overall, Group B develops GBs at an earlier age, but observed survival remains similar to those with GBs as the only primary. Moreover, this subset also exhibit different proportions of the types of GBs, and well as differences in other key clinical factors (namely, gender and tumor size at presentation). Prior treatments for lower grade gliomas likely explain some of the differences noted regarding management course after diagnosis of GB.

Intracranial hemangioblastoma - A SEER-based analysis 2004-2013

Introduction

Intracranial hemangioblastoma (HB) is a rare pathology. Limited data exist regarding its epidemiology.

Methods

With the SEER-18 registry database, information from all patients diagnosed with intracranial HB from 2004 to 2013 were extracted, including age, gender, race, marital status, presence of surgery, extent of surgery, receipt of radiation, tumor size, tumor location, and follow-up data. Age-adjusted incidence rates and overall survival (OS). Cox proportional hazards model was employed for both univariate and multivariate analyses.

Results

A total of 1307 cases were identified. The overall incidence of intracranial hemangioblastoma is 0.153 per 100,000 person-years [95% confidence interval (CI)=0.145–0.162]. Through univariate analysis, age < 40 [hazard ratio (HR)=0.277, p<0.001], no radiation [HR=0.56, p=0.047], and presence of surgery [HR=0.576, p=0.012] are significant positive prognostic factors. Caucasian race [HR=1.42, p=0.071] and female gender [HR=0.744, p=0.087] exhibit noticeable trends towards positive prognosis. Through multivariate analysis, younger age [HR=1.053, p < 0.01], race [HR=1.916, p<0.01], and presence of surgery [HR=0.463, p<0.01 were significant independent prognostic factors.

Conclusion

Clinical factors such as younger age, Caucasian race, and presence of surgery are significant independent factors for overall survival in patients with HBs. Though analysis regarding extent of surgery did not produce a meaningful relationship, this may be related to surgical bias / expertise. Moreover, no validation for radiation therapy was identified, but this may be related to short follow up intervals and the variable growth patterns of HBs.

Pathology-MRI Correlations in Diffuse Low-Grade Epilepsy Associated Tumors

It is recognized that IDH mutation negative, low-grade epilepsy associated tumors (LEAT) can show diffuse growth patterns and lack the diagnostic hallmarks of either classical dysembryoplastic neuroepithelial tumors (DNT) or typical ganglioglioma. “Nonspecific or diffuse DNT” and more recently “polymorphous low-grade neuroepithelial tumor of the young” have been terms used for these entities. There are few reports on the MRI recognition of these diffuse glioneuronal tumors (dGNT), which is important in planning the extent of surgical resection. In 27 LEATs T1, T2, FLAIR, and postcontrast T1 MRI were evaluated and the pathology reviewed, including immunostaining for NeuN, CD34, MAP2, and IDH1. Each case was then independently classified by pathology or MRI as simple DNT, complex DNT, or dGNT. There was agreement in 23/27 (85%; Kappa score 0.62; p < 0.01). In 4 cases, there was discrepancy in the diagnosis of simple versus complex DNT but 100% agreement achieved for dGNT. DNT showed significantly more expansion of the cortex, cystic change and ventricle extension than dGNT. dGNT showed significantly more subcortical T2w hyperintensity and focal cortical atrophy which correlated on pathology with CD34 expression, cortical neuronal loss and white matter rarefaction. There was no distinct cortical dysplasia component identified by MRI or pathology in any case. This study highlights that dGNT can be reliably discriminated on MRI from DNT.