Clinical and prognostic features of adult patients with gangliogliomas

Clinical outcomes of adults with intracranial grade 1 and 2 ganglioglioma

Ganglioglioma is a rare primary brain tumour that most frequently occurs in children and young adults. They are generally low-grade and have a favourable prognosis, but there is limited literature to guide the optimal management. The aim of this study was to investigate the clinical outcomes of adults with intracranial ganglioglioma, and to determine the frequency and duration of radiological follow-up. Thirteen adult patients with CNS WHO grade 1 and 2 ganglioglioma were identified retrospectively from case records at a tertiary neurosurgical centre between 2010 and 2022. Patient characteristics, magnetic resonance imaging (MRI) features, and clinical outcomes were obtained. Surgery was classified as gross total (GTR) or subtotal (STR) resection. 84.6 % (n = 11) of patients had temporal lobe tumours, with most (69.2 %) presenting with seizures, at a median age of 29.0 years. GTR and STR were achieved in nine and five patients, respectively. No patients received adjuvant radiotherapy. During the median follow-up period of 8.9 years there was no radiological recurrence after GTR, and only one recurrence after STR at 65 months that did not require treatment. There was no patient mortality. Two patients continued to have seizures at last clinical follow-up. Low grade adult intracranial ganglioglioma has an excellent prognosis, with a recurrence rate below 10 % in this series. Long-term surveillance is not necessarily required if GTR has been achieved and patients can be considered for discharge after annual MRI for 5 years. In patients where only STR is achieved, annual MRI is required although the progression/recurrence rate remains low and asymptomatic.

BRAF V600E Mutation in Ganglioglioma: Impact on Epileptogenicity and Implications for Surgical Strategy

OBJECTIVE

Gangliogliomas are commonly found pathologies in patients undergoing epilepsy surgery. While resections can be curative, seizure relapses occur. Expression of CD34 and the BRAF V600E mutation are the most common molecular biomarkers found in gangliogliomas, but their influence on seizure outcomes is unclear. We therefore reviewed our experience over two decades to better describe prognostic factors.

METHODS

We performed a retrospective chart review of all patients operated on for ganglioglioma at our institution since the year 2000. We included patients with preoperative epilepsy and a minimum follow-up of 1 year. Available tumor specimens were immunohistochemically stained for CD34 and BRAF V600E.

RESULTS

We included 62 patients with epilepsy operated for ganglioglioma. Lesionectomies were performed in 32 (51.6%), extended resections in 21 (33.9%), and partial resections in 9 cases (14.5%). Residual tumor mass on postoperative MRI was diagnosed in 21 patients (33.9%). CD34 reactivity was found in 57 patients (91.9%) and the BRAF V600E mutation was detected in 30 patients (48.4%). Patients with a BRAF V600E mutation were younger at the time of epilepsy onset (9.1 years vs. 15.2 years) and surgery (14.5 years vs. 23.7 years). Residual tumor was the largest risk factor for seizure relapses (hazard ratio 8.45) and the BRAF V600E mutation also increased this risk (hazard ratio 3.94).

CONCLUSIONS

BRAF V600E status in patients with ganglioglioma-associated epilepsy is a potential biomarker to stratify the risk for seizure relapse after surgery. BRAF V600E-positive patients might benefit from a more aggressive surgical strategy.

Epilepsy in LEAT and other brain tumors: A focused review

Of all patients with brain tumors, about 30-50% suffer from epileptic seizures. The probability of developing epilepsy is particularly high in low-grade, epilepsy-associated brain tumors (LEAT). LEATs often show a pronounced network dysfunction with extensive EEG pathologies and cognitive deficits, and the epilepsies are often difficult to treat. In high-grade brain tumors, epileptic seizures determine morbidity and quality of life. The underlying mechanisms of epileptogenesis of brain tumors are increasingly understood and raise hope for personalized therapeutic approaches. This short, focused review provides an overview of the current understanding of brain tumor-related epilepsies. This paper was presented at 16th International Epilepsy Course and Colloquium held in Frankfurt a.M., Germany, September 2024.

Anatomy-guided resections for paralimbic tumors in the temporo-insular region: combining tumor and epilepsy surgery concepts

Object

Tumors in the temporo-mesial region often extend into the insula and vice versa. The present study investigated the results of a surgical strategy that combines principles of tumor and epilepsy surgery.

Methods

We retrospectively analyzed 157 consecutive patients with intrinsic brain tumors in the temporo-mesial region, with varying degrees of extensions into the insula (44 patients, 28.0%). The surgical strategy utilized "anatomy-guided resection," targeting specific anatomical compartments infiltrated by the tumor (e.g., temporal pole, anterior temporo-mesial region = uncus and hippocampal head, posterior temporo-mesial, insula) rather than treating the tumor as a single mass.

Results

The most frequent histologies were ganglioglioma CNS WHO grade 1 (55 patients, 35.0%) and IDH1 wildtype glioblastoma (36 patients, 22.9%). Tumor infiltration was most commonly found in the anterior temporo-mesial compartment (145 patients, 92.4%). An anterior temporal lobectomy was part of the surgical strategy in 131 cases (83.4%). Seventy-six patients (48.4%) with drug-resistant epilepsy underwent a formal presurgical epilepsy work-up, including depth electrode placement in three cases. Complete resections were achieved in 117 patients (74.5%), with supramarginal resections performed in 89 cases (56.7%). Four patients experienced non-temporary neurological complications (CTCAE grade 3-5). At 6 months, 127 of 147 assessable patients (86.4%) were free from seizures or auras (ILAE class 1), excluding early postoperative seizures (<30 days). At 24 months, 122 of 144 assessable cases (84.7%) remained seizure-free (ILAE class 1). Kaplan-Meier estimates for 5-year overall survival were 98.5% for non-recurrent glioneuronal tumors. The 2-year overall survival estimates were 96.0% for 24 primary diffuse CNS WHO grade 2 and 3 gliomas and 55.2% for 30 patients undergoing first surgeries for glioblastomas/astrocytomas CNS WHO grade 4.

Conclusion

Combining both epilepsy and tumor surgery concepts in the surgical treatment of intrinsic brain tumors involving the mesial temporal lobe, often extending into the insula, led to more extensive resections, improved seizure outcomes, and potentially even better patient survival outcomes.

Thalamic Ganglioglioma Treated With Radical Radiotherapy: A Rare Location and an Exclusive Form of Treatment

Gangliogliomas (GG) are rare primary central nervous system (CNS) tumors. These CNS tumors are more commonly located at the supratentorial level. The treatment of choice for these tumors is surgical resection, and the role of radiotherapy remains controversial. A 61-year-old woman who presented with seizures underwent a magnetic resonance imaging (MRI), which showed a left-side thalamic lesion with one solid and two cystic components. A neuronavigation-guided brain biopsy of the lesion established the diagnosis of GG, with expression of glial fibrillary acidic protein (GFAP) for glial cells and neuron-specific enolase (NSE) and synaptophysin for ganglion cells. Due to the location of the lesion, the patient underwent radical radiotherapy. Post-treatment MRIs revealed a reduction in tumor dimensions. In conclusion, we emphasize the role of radiotherapy in the treatment of cerebral GG.

Contralateral transcallosal transfalcine approach for bilateral intra-extraventricular anaplastic ganglioglioma via 'the trans-tumoral route': a technical case instruction

BACKGROUND

Bilateral, biventricular lesions present a challenging scenario in neurosurgery, often requiring complex surgical techniques for management. Gangliogliomas (GG), while typically indolent, can manifest as anaplastic variants (AGG), necessitating comprehensive treatment strategies. This case study explores a unique surgical approach for a patient with bilateral, intra-extraventricular lesions infiltrating the corpus callosum, highlighting the complexities of managing such cases.

METHODS

A 63-year-old female presented with a progressive intraventricular lesion infiltrating the left frontal lobe, diagnosed initially as a ganglioglioma. Following resection and histological examination, the lesion was confirmed as a WHO Grade 1 ganglioglioma. Subsequently, a contralateral lesion emerged, necessitating a novel surgical approach to achieve maximal safe resection while minimising neurological deficits. The technique involved extending the surgical corridor contralaterally along the tumour route, guided by neuronavigation and fluorescence imaging.

RESULTS

The surgical approach enabled maximal safe resection of the lesion, with postoperative imaging confirming complete resection in most sites except for a known infiltration in the right posterior lateral ventricle. Histological examination revealed AGG, prompting subsequent adjuvant radiotherapy due to its aggressive nature.

CONCLUSION

The management of bilateral, biventricular lesions such as AGG requires innovative surgical approaches tailored to individual patient characteristics. The case highlights the efficacy of a transtumoral approach in achieving maximal safe resection while minimising neurological sequelae. Moreover, it underscores the importance of comprehensive treatment strategies, including adjuvant therapies, in addressing aggressive histological variants of gangliogliomas.

Incidence and survival characteristics of pediatric ganglioglioma from 2004 to 2018, with focus on infratentorial sites

Background

Ganglioglioma (GG) is a slow-growing glioneuronal neoplasm, most frequently seen in the supratentorial location in older children and associated with epilepsy syndromes. GG is rare in the infratentorial location, hence we embarked upon analyzing the National Cancer Institute's (NCI) Survival, Epidemiology, and End Results (SEER) database to better evaluate GG outcomes by location in comparison to the broader pediatric low-grade glioma (pLGG) population.

Methods

Pediatric patients diagnosed with GG and pLGG from 2004 to 2018 were included in the study. Their demographic, clinical, and survival characteristics were analyzed using SEER*Stat.

Results

This study describes the largest cohort of pediatric GG, including 852 cases from year 2004 to 2018, with focus on infratentorial sites. Patients with brainstem GG or those with subtotally resected disease were identified as having higher risk of death.

Conclusions

Our analysis highlights brainstem GG as a high-risk, poor-prognostic subgroup and elaborates on the incidence and survival characteristic of this lesser-known subgroup.

Extremely slow-growing cerebellar ganglioglioma in an elderly patient

Background

Gangliogliomas account for 0.4% of primary brain tumors. They mainly occur in the supratentorial compartment and typically affect only children and young adults. We present an especially rare case of cerebellar ganglioglioma in an elderly patient.

Case Description

A 76-year-old Japanese woman presented with headache and nausea from 1 month previously. She had been diagnosed with a cerebellar tumor in her childhood, but the lesion was asymptomatic at that time, and there was no evidence of an increase in size, so it had been monitored without surgery. At the time of presentation, she had not been examined for approximately ten years. On admission, magnetic resonance imaging indicated a T2 hypertense cyst in the cerebellar vermis. Post-contrast T1 imaging showed an enhanced mural nodule in the cyst. Cerebral angiography showed that none of the vertebral arteries were significant feeders. The tumor was removed through posterior fossa craniotomy. The histopathological diagnosis was ganglioglioma. The patient's headache and nausea improved after surgery.

Conclusion

Our patient presented a very rare case of extremely slow-growing elderly ganglioglioma in the cerebellum. In patients with gangliogliomas, long-term follow-up is important because the disease may become symptomatic at an older age.

Adult-type Diffuse Gliomas

OBJECTIVE

This article highlights key aspects of the diagnosis and management of adult-type diffuse gliomas, including glioblastomas and IDH-mutant gliomas relevant to the daily practice of the general neurologist.

LATEST DEVELOPMENTS

The advances in molecular characterization of gliomas have translated into more accurate prognostication and tumor classification. Gliomas previously categorized by histological appearance solely as astrocytomas or oligodendrogliomas are now also defined by molecular features. Furthermore, ongoing clinical trials have incorporated these advances to tailor more effective treatments for specific glioma subtypes.

ESSENTIAL POINTS

Despite recent insights into the molecular aspects of gliomas, these tumors remain incurable. Care for patients with these complex tumors requires a multidisciplinary team in which the general neurologist has an important role. Efforts focus on translating the latest data into more effective therapies that can prolong survival.

'Déjà Vu', a Mind Trick or a Warning Sign? A Case Report

N/a.

Intraventricular ganglioglioma: a rare case report

We report a case of an intraventricular ganglioglioma in a 23-year-old male. The patient presented with a 3-day history of headache and vomiting. Preoperative brain imaging revealed a calcified lesion within the trigone of the right lateral ventricle, with irregular enhancement, causing entrapment of the temporal horn of the lateral ventricle. At surgery, the lesion was haemorrhagic, easily friable and exhibited evidence of a previous recent haemorrhage. Histological and immunohistochemical studies showed a ganglioglioma with World Health Organisation Grade 1 characteristics. Gangliogliomas of the central nervous system are uncommon, and rarely occur in the lateral ventricle.

DNA methylation-based classification of glioneuronal tumours synergises with histology and radiology to refine accurate molecular stratification

AIMS

Glioneuronal tumours (GNTs) are poorly distinguished by their histology and lack robust diagnostic indicators. Previously, we showed that common GNTs comprise two molecularly distinct groups, correlating poorly with histology. To refine diagnosis, we constructed a methylation-based model for GNT classification, subsequently evaluating standards for molecular stratification by methylation, histology and radiology.

METHODS

We comprehensively analysed methylation, radiology and histology for 83 GNT samples: a training cohort of 49, previously classified into molecularly defined groups by genomic profiles, plus a validation cohort of 34. We identified histological and radiological correlates to molecular classification and constructed a methylation-based support vector machine (SVM) model for prediction. Subsequently, we contrasted methylation, radiological and histological classifications in validation GNTs.

RESULTS

By methylation clustering, all training and 23/34 validation GNTs segregated into two groups, the remaining 11 clustering alongside control cortex. Histological review identified prominent astrocytic/oligodendrocyte-like components, dysplastic neurons and a specific glioneuronal element as discriminators between groups. However, these were present in only a subset of tumours. Radiological review identified location, margin definition, enhancement and T2 FLAIR-rim sign as discriminators. When validation GNTs were classified by SVM, 22/23 classified correctly, comparing favourably against histology and radiology that resolved 17/22 and 15/21, respectively, where data were available for comparison.

CONCLUSIONS

Diagnostic criteria inadequately reflect glioneuronal tumour biology, leaving a proportion unresolvable. In the largest cohort of molecularly defined glioneuronal tumours, we develop molecular, histological and radiological approaches for biologically meaningful classification and demonstrate almost all cases are resolvable, emphasising the importance of an integrated diagnostic approach.

Benign Glioma

Benign glioma broadly refers to a heterogeneous group of slow-growing glial tumors with low proliferative rates and a more indolent clinical course. These tumors may also be described as "low-grade" glioma (LGG) and are classified as WHO grade I or II lesions according to the Classification of Tumors of the Central Nervous System (CNS) (Louis et al. in Acta Neuropathol 114:97-109, 2007). Advances in molecular genetics have improved understanding of glioma tumorigenesis, leading to the identification of common mutation profiles with significant treatment and prognostic implications. The most recent WHO 2016 classification system has introduced several notable changes in the way that gliomas are diagnosed, with a new emphasis on molecular features as key factors in differentiation (Wesseling and Capper in Neuropathol Appl Neurobiol 44:139-150, 2018). Benign gliomas have a predilection for younger patients and are among the most frequently diagnosed tumors in children and young adults (Ostrom et al. in Neuro Oncol 22:iv1-iv96, 2020). These tumors can be separated into two clinically distinct subgroups. The first group is of focal, well-circumscribed lesions that notably are not associated with an increased risk of malignant transformation. Primarily diagnosed in pediatric patients, these WHO grade I tumors may be cured with surgical resection alone (Sturm et al. in J Clin Oncol 35:2370-2377, 2017). Recurrence rates are low, and the prognosis for these patients is excellent (Ostrom et al. in Neuro Oncol 22:iv1-iv96, 2020). Diffuse gliomas are WHO grade II lesions with a more infiltrative pattern of growth and high propensity for recurrence. These tumors are primarily diagnosed in young adult patients, and classically present with seizures (Pallud et al. Brain 137:449-462, 2014). The term "benign" is a misnomer in many cases, as the natural history of these tumors is with malignant transformation and recurrence as grade III or grade IV tumors (Jooma et al. in J Neurosurg 14:356-363, 2019). For all LGG, surgery with maximal safe resection is the treatment of choice for both primary and recurrent tumors. The goal of surgery should be for gross total resection (GTR), as complete tumor removal is associated with higher rates of tumor control and seizure freedom. Chemotherapy and radiation therapy (RT), while not typically a component of first-line treatment in most cases, may be employed as adjunctive therapy in high-risk or recurrent tumors and in some select cases. The prognosis of benign gliomas varies widely; non-infiltrative tumor subtypes generally have an excellent prognosis, while diffusely infiltrative tumors, although slow-growing, are eventually fatal (Sturm et al. in J Clin Oncol 35:2370-2377, 2017). This chapter reviews the shared and unique individual features of the benign glioma including diffuse glioma, pilocytic astrocytoma and pilomyxoid astrocytoma (PMA), subependymal giant cell astrocytoma (SEGA), pleomorphic xanthoastrocytoma (PXA), subependymoma (SE), angiocentric glioma (AG), and chordoid glioma (CG). Also discussed is ganglioglioma (GG), a mixed neuronal-glial tumor that represents a notable diagnosis in the differential for other LGG (Wesseling and Capper 2018). Ependymomas of the brain and spinal cord, including major histologic subtypes, are discussed in other chapters.

Anaplastic ganglioglioma - a diagnosis comprising several distinct tumour types

Anaplastic ganglioglioma is a rare tumour and diagnosis has been based on histological criteria. The 5^th edition of the World Health Organization Classification of Tumours of the Central Nervous System (CNS WHO) does not list anaplastic ganglioglioma as a distinct diagnosis due to lack of molecular data in previous publications AIM: We retrospectively compiled a cohort of 54 histologically diagnosed anaplastic gangliogliomas to explore whether the molecular profiles of these tumours represent a separate type or resolve into other entities METHODS: Samples were subjected to histological review, DNA methylation profiling and next generation sequencing. Morphologic and molecular data were summarised to an integrated diagnosis RESULTS: The majority of histologically diagnosed anaplastic gangliogliomas resolved into CNS WHO diagnoses of glial tumours, most commonly pleomorphic xanthoastrocytoma (16/54), glioblastoma, IDH wildtype and diffuse paediatric-type high-grade glioma, H3 wildtype and IDH wildtype (11 and 2/54) followed by low-grade glial or glioneuronal tumours including pilocytic astrocytoma, dysembryoplastic neuroepithelial tumour and diffuse leptomeningeal glioneuronal tumour (5/54), IDH mutant astrocytoma (4/54) and others (6/54). A subset of tumours (10/54) was not assignable to a CNS WHO diagnosis and common molecular profiles pointing to a separate entity were not evident CONCLUSION: In summary, we show that tumours histologically diagnosed as anaplastic ganglioglioma comprise a wide spectrum of CNS WHO tumour types with different prognostic and therapeutic implications. We therefore suggest assigning this designation with caution and recommend comprehensive molecular workup.

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.

Dabrafenib plus trametinib in patients with BRAFV600E-mutant low-grade and high-grade glioma (ROAR): a multicentre, open-label, single-arm, phase 2, basket trial

BACKGROUND

Effective treatments are needed to improve outcomes for high-grade glioma and low-grade glioma. The activity and safety of dabrafenib plus trametinib were evaluated in adult patients with recurrent or progressive BRAF^V600E mutation-positive high-grade glioma and low-grade glioma.

METHODS

This study is part of an ongoing open-label, single-arm, phase 2 Rare Oncology Agnostic Research (ROAR) basket trial at 27 community and academic cancer centres in 13 countries (Austria, Belgium, Canada, France, Germany, Italy, Japan, the Netherlands, Norway, South Korea, Spain, Sweden, and the USA). The study enrolled patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0, 1, or 2. Patients with BRAF^V600E mutation-positive high-grade glioma and low-grade glioma received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily orally until unacceptable toxicity, disease progression, or death. In the high-grade glioma cohort, patients were required to have measurable disease at baseline using the Response Assessment in Neuro-Oncology high-grade glioma response criteria and have been treated previously with radiotherapy and first-line chemotherapy or concurrent chemoradiotherapy. Patients with low-grade glioma were required to have measurable non-enhancing disease (except pilocytic astrocytoma) at baseline using the Response Assessment in Neuro-Oncology low-grade glioma criteria. The primary endpoint, in the evaluable intention-to-treat population, was investigator-assessed objective response rate (complete response plus partial response for high-grade glioma and complete response plus partial response plus minor response for low-grade glioma). This trial is ongoing, but is closed for enrolment, NCT02034110.

FINDINGS

Between April 17, 2014, and July 25, 2018, 45 patients (31 with glioblastoma) were enrolled into the high-grade glioma cohort and 13 patients were enrolled into the low-grade glioma cohort. The results presented here are based on interim analysis 16 (data cutoff Sept 14, 2020). In the high-grade glioma cohort, median follow-up was 12·7 months (IQR 5·4-32·3) and 15 (33%; 95% CI 20-49) of 45 patients had an objective response by investigator assessment, including three complete responses and 12 partial responses. In the low-grade glioma cohort, median follow-up was 32·2 months (IQR 25·1-47·8). Nine (69%; 95% CI 39-91) of 13 patients had an objective response by investigator assessment, including one complete response, six partial responses, and two minor responses. Grade 3 or worse adverse events were reported in 31 (53%) patients, the most common being fatigue (five [9%]), decreased neutrophil count (five [9%]), headache (three [5%]), and neutropenia (three [5%]).

INTERPRETATION

Dabrafenib plus trametinib showed clinically meaningful activity in patients with BRAF^V600E mutation-positive recurrent or refractory high-grade glioma and low-grade glioma, with a safety profile consistent with that in other indications. BRAF^V600E testing could potentially be adopted in clinical practice for patients with glioma.

FUNDING

Novartis.

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.

[Features of the neuroradiological picture of ganglioglioma on the example of 20 clinical cases]

OBJECTIVE

To analyze the images obtained during pre-surgical neuroimaging in patients with gangliomas for the presence of specific signs and verification of the neoplastic process.

MATERIAL AND METHODS

The results of presurgical MRI (3.0, 1.5 Tesla) of 20 patients with gangliomas were analyzed to identify specific signs of a neuronal-glial tumor and verify the neoplastic process based on the results obtained and a review of the literature. In addition to high-resolution MRI (HR MRI), various protocol modifications were applied to patients with epileptogenic pathological substrates of unclear etiology, including tractography (DTI) and contrast-free MR perfusion (ASL). In 5 cases, a multi-modal study was performed that combined the results of CT, routine MRI, HR MRI, functional MRI (fMRI) in various combinations and PET CT.

RESULTS AND CONCLUSION

In 17 cases, patients underwent epileptic surgery. Three patients without epilepsy were operated on for a tumor diagnosed by radiological examination. In all 20 cases, gangliogliomas were verified, including 1 anaplastic, 1 infantile desmoplastic, and another patient had histological samples showing signs of a composite tumor. Combination with FCD IIIb was observed in 3 cases. Two patients had a double pathology (cases of tumors combination with lissencephaly and neuronal heterotopia) and another had a composite neuronal-glial tumor. In 15 cases, gangliogliomas showed neuroradiological features typical for dysembryoplastic neuroepithelial tumor (DNT) such as multicystic, nodular, and diffuse (dysplastic) described in the literature. In addition, in 9 cases, they had significant signs of neoplastic process such as contrast enhancement, continued growth and remodeling of the underlying bone. Verification of the neoplastic process based on the results of neuroradiological studies was difficult in 6 cases. In 2 cases, it was not possible to confirm the presence of neoplasm by radiological methods, and in 1 patient, the verification of the tumor during differential diagnosis took more than 8 years. The most common differential diagnosis was performed with DNT and FCD type IIb, which have a number of similar neuroradiological features.

Low-grade gangliogliomas in adults: A population-based study

BACKGROUND

Low-grade gangliogliomas (GGs) are rare tumors of the central nervous system in adults. This study aims to define their characteristics, prognostic factors, and the impact of different treatment patterns on survival.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to investigate the potential clinicopathological factors of low-grade GGs in adult patients (age ≥18 years). Kaplan-Meier method and Cox regression model were utilized to evaluate the associations between variables and overall survival (OS).

RESULTS

A total of 703 adult patients diagnosed with low-grade GGs were identified between 2004 and 2016, with a median follow-up period of 60.0 months. The median age at diagnosis was 32.0 years, with 50.1% of patients being male, 84.2% white people, and 40.2% of married status. The predominant tumor site was located in temporal lobe (38.8%). The median OS time for the whole cohort was not reached. The 5- and 10-year OS rates for patients underwent gross total resection (GTR) were 92.5% and 87.2%, respectively. Univariate and multivariate analysis showed age, gender, tumor site, and treatment pattern were significant factors for OS. The employment of adjuvant radiotherapy (RT) and/or chemotherapy would significantly shorten OS time.

CONCLUSIONS

This is the largest retrospective study of adult low-grade GGs up to date. Younger age, female gender, temporal lobe location, and GTR indicated better survival. Adjuvant RT and/or chemotherapy should not be considered after whatever surgery in adult patients with low-grade GGs, unless the malignant transformation has been confirmed.

Clinicopathologic Features of Diencephalic Neuronal and Glioneuronal Tumors

Neuronal/mixed glioneuronal tumors are central nervous system neoplasms composed of neoplastic neuronal cell components or a mixture of glial and neuronal elements. They occur in cerebral hemispheres, posterior fossa, and spinal cord. Compared with other tumors at these locations, diencephalic neuronal/glioneuronal tumors are very rare and therefore not well characterized. We hereby performed clinicopathologic evaluation on 10 neuronal/glioneuronal tumors arising from the diencephalic region. Morphologically, these tumors resemble their histologic counterparts in other locations, except that lymphocytic infiltrates and microcalcifications are more common than Rosenthal fibers or eosinophilic granular bodies. The BRAFV600 mutation rate is 75%. Given the high percentage of samples being small biopsy specimens, the subtle histologic features and molecular findings greatly aided in establishing the pathologic diagnosis in several cases. At a median follow-up of 42 months, 71% of the tumors demonstrated radiological recurrence or progression, with median progression-free survival of 18 months. Recurrence/progression is observed in tumors across different histologic subtypes, necessitating additional therapies in 56% of the cases. Despite their bland histology, diencephalic neuronal/glioneuronal tumors are not clinically indolent. Their frequent recurrences warrant a close follow-up, and the prevalent BRAF mutation makes MAPK pathway inhibition a plausible treatment option when conventional therapies fail.

Short-term outcome following surgery for rare brain tumor entities in adults: a Swedish nation-wide registry-based study and comparison with SEER database

Objective

To investigate outcomes after surgery for rare brain tumors using the Swedish Brain Tumor Registry (SBTR).

Methods

This is a nationwide study of patient in the SBTR, validated in the Surveillance, Epidemiology, and End Results (SEER) registries. We included all adults diagnosed 2009–2015 with a rare brain tumor entity (n = 216), defined as ependymoma (EP, n = 64), subependymoma (SUBEP, n = 21), ganglioglioma (GGL, n = 54), pilocytic astrocytoma (PA, n = 56) and primitive neuroectodermal tumor (PNET, n = 21). We analyzed symptomatology, tumor characteristics and outcomes.

Results

Mean age was 38.3 ± 17.2 years in GGL, 36.2 ± 16.9 in PA, 37.0 ± 19.1 in PNET, 51.7 ± 16.3 in EP and 49.8 ± 14.3 in SUBEP. The most common symptom was focal deficit (39.6–71.4%), and this symptom was most common in GGL patients with 64.2% of GGL presenting with seizures. Most patients had no or little restriction in activity before surgery (Performance Status 0–1), although up to 15.0% of PNET patients had a performance status of 4. Gross total resection was achieved in most (> 50%) tumor categories. Incidence of new deficits was 11.1–34.4%. In terms of postoperative complications, 0–4.8% had a hematoma of any kind, 1.9–15.6% an infection, 0–7.8% a venous thromboembolism and 3.7–10.9% experienced a complication requiring reoperation. There were 3 deaths within 30-days of surgery, and a 1-year mortality of 0–14.3%.

Conclusion

We have provided benchmarks for the current symptomatology, tumor characteristics and outcomes after surgery for rare brain tumors as collected by the SBTR and validated our results in an independent registry. These results may aid in clinical decision making and advising patients.

Anaplasic ganglioglioma: Cervical-dorso-lumbar leptomeningeal dissemination. About a case

Gangliogliomas are well-differentiated, slow-growing tumors. The majority are gradeI of WHO. It appears predominantly in children and young adults. Most are located at the temporal lobe, and as symptomatology more frequent epileptic seizures of difficult pharmacological control. In general, they have a good prognosis after surgical resection. The anaplasic variant, considered to be gradeIII of the WHO, presents greater clinical and radiological aggressiveness. Leptomeningeal dissemination is exceptional in these types of tumors, but when diagnosed it presents a rapidly progressive and fatal course for the patient.

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.

Combination of BRAF and MEK inhibition in BRAF V600E mutant low-grade ganglioglioma

WHAT IS KNOWN AND OBJECTIVE

Post-surgical management of low grade gangliogliomas is controversial with paucity of data for the use of chemotherapy. BRAF mutations are present in a number of glioma subtypes and offer an opportunity for treatment with targeted therapy.

CASE SUMMARY

A 32-year-old man with an unresectable, BRAF V600E mutant, WHO grade 1 ganglioglioma is commenced on combination BRAF and MEK inhibition (vemurafenib and cobimetinib). Partial radiological and clinical response was noted after 13 weeks of treatment. Treatment complication with grade 2 skin and liver toxicity was resolved with dose interruption and reduction.

WHAT IS NEW AND CONCLUSION

Combination BRAF and MEK inhibition present a safe and feasible treatment strategy in unresectable BRAF V600E mutant low grade ganglioglioma.

Prolonged Response Induced by Single Agent Vemurafenib in a BRAF V600E Spinal Ganglioglioma: A Case Report and Review of the Literature

Spinal ganglioglioma is a rare low-grade, slow-growing tumor of the central nervous system affecting mostly children and young adults. After surgery, some patients show tumor recurrence and/or malignant transformation. Gangliogliomas harbor molecular deficiencies such as mutations in the B-rapidly accelerated fibrosarcoma (BRAF) gene, resulting in activation of a downstream signaling pathway and cancer development. Vemurafenib is a BRAF inhibitor used to treat patients with BRAF V600E-mutated cancer. Although a few studies have reported the clinical responses in gangliogliomas, the sequence and duration of treatment have not been established. We describe a case of an adult with a progressive BRAF V600E mutant spinal cord ganglioglioma 9 years after surgery who was treated with vemurafenib. This treatment resulted in a partial response within 2 months, which was sustained for more than a year. The patient then decided to stop treatment because of side effects. Despite this decision, the tumor showed no sign of progression 21 months after treatment discontinuation. This is the first reported case of a response to vemurafenib in an adult with progressive spinal cord BRAF V600E-mutated ganglioglioma which was sustained after treatment discontinuation.

Impact of surgery, adjuvant treatment, and other prognostic factors in the management of anaplastic ganglioglioma

BACKGROUND/PURPOSE

Anaplastic ganglioglioma (AGG) is a rare tumor with both glial and neuronal component accounting for less than 1% of all CNS tumors with limited information about the optimum treatment and outcome of these tumors.

METHOD AND MATERIALS

We did a thorough search of the PubMed with the following MesH terms: "Ganglioglioma; Anaplastic ganglioglioma; Ganglioglioma AND treatment; and Anaplastic ganglioglioma AND survival" to find all possible publications related to AGG to perform an individual patient data analysis and derive the survival outcome and optimum treatment of these tumors.

RESULTS

A total of 56 articles were retrieved pertaining to AGG with 88 patients. However, a total of 40 publications found eligible with 69 patients for individual patient data analysis. Median age for the entire cohort was 16 years (range 0.2-77 years). Surgical details were available for 64 patients. A gross total or near total resection was reported in 21 cases (32.8%), subtotal resection or debulking was reported in 25 cases (39.1%). Surgical details were available for 64 patients. A gross total or near total resection was reported in 21 cases (32.8%), and subtotal resection or debulking was reported in 25 cases (39.1%). Median overall survival (OS) was 29 months [95% CI 15.8-42.2 months] with 2- and 5-year OS 61 and 39.4% respectively.

CONCLUSION

AGG is associated with a dismal. Pediatric age and a gross total resection of tumor confer a better progression-free survival and OS. Hence, surgery should remain the cornerstone of therapy. However, because of modest survival, there is enough opportunity to improve survival with addition of adjuvant radiation and chemotherapy. A whole genome sequencing and molecular characterization would help to derive the best treatment option.

Subtotal Resection of an Anaplastic Ganglioglioma in Pregnancy

Background

Anaplastic ganglioglioma is a rare malignant brain tumor associated with high morbidity and mortality. The diagnosis of a central nervous system malignancy in the early 3rd trimester presents management challenges to both neurosurgeons and obstetricians.

Case

A 33-year-old woman, gravida 2 para 1, presented at 28 6/7 weeks with four months of worsening headaches, nausea, vomiting, and mental status changes due to a 7.5 cm anaplastic ganglioglioma. Maternal deterioration necessitated subtotal tumor debulking allowing prolongation of the gestation to 34 6/7 weeks. After delivery, the patient underwent further resection, followed by chemotherapy and radiation. Both mother and infant are well.

Discussion

This case underscores the importance of timely diagnostic imaging in pregnant women and demonstrates subtotal tumor debulking as a viable means of prolonging gestation.

A case of adult anaplastic cerebellar ganglioglioma

Background:

Anaplastic posterior fossa ganglioglioma in adults is exceedingly rare. To date, only one case of adult anaplastic posterior fossa ganglioglioma has been reported in the English literature and none has been described at the cerebellum. To our knowledge, this report is the third case of malignant posterior fossa ganglioglioma in adults and the first at the cerebellum. In general, this entity can be misdiagnosed preoperatively as a primary posterior fossa neoplasm, and by reporting our clinical and radiographic observations we want to add to the existing literature on this rare entity.

Case Description:

A 40-year-old man presented with a history of headaches and dizziness and progressive gait disturbance and was diagnosed with anaplastic ganglioglioma in the posterior fossa.

Conclusions:

Although rare, our case demonstrates that anaplastic ganglioglioma should be considered in the differential diagnosis of infratentorial tumors in adult patients.

A rare association of ganglioglioma and cavernous malformation: Report of two cases and literature review

Background:

Some glial tumors have been observed in association with different types of vascular malformations of the brain (angiogliomas). However, the association of ganglioglioma with other vascular malformations is extremely rare, with only few cases reported in the literature, one of which is referred to as “angioganglioglioma.”

Case Description:

Two patients presented with acute onset of neurological symptoms, with magnetic resonance imaging (MRI) finding of cavernoma of the left middle cerebellar penduncle, and small mass of the chiasmatic region, respectively. After microsurgical excision, histopathological examination revealed mixed ganglioglioma and cavernous malformation in both cases. Postoperative course was uneventful, and follow-up MRI showed complete removal of the tumor with no recurrence after 4 years.

Conclusions:

Angiogliomas are very uncommon tumors. In literature, we found different interpretations of such lesions, although they should most probably be considered as distinct pathological entities. Although the association of ganglioglioma with cavernoma is extremely rare, it could be considered as a most peculiar form of angioglioma, and supports the existence of angioganglioglioma.

Co-occurrence of histone H3 K27M and BRAF V600E mutations in paediatric midline grade I ganglioglioma

Ganglioglioma (GG) is a grade I tumor characterized by alterations in the MAPK pathway, including BRAF V600E mutation. Recently, diffuse midline glioma with an H3 K27M mutation was added to the WHO 2016 classification as a new grade IV entity. As co-occurrence of H3 K27M and BRAF V600E mutations has been reported in midline tumors and anaplastic GG, we searched for BRAF V600E and H3 K27M mutations in a series of 54 paediatric midline grade I GG (midline GG) to determine the frequency of double mutations and its relevance for prognosis. Twenty-seven patients (50%) possessed the BRAF V600E mutation. The frequency of the co-occurrence of H3F3A/BRAF mutations at diagnosis was 9.3%. No H3 K27M mutation was detected in the absence of the BRAF V600E mutation. Double-immunostaining revealed that BRAF V600E and H3 K27M mutant proteins were present in both the glial and neuronal components. Immunopositivity for the BRAF V600E mutant protein correlated with BRAF mutation status as detected by massARRAY or digital droplet PCR. The median follow-up of patients with double mutation was 4 years. One patient died of progressive disease 8 years after diagnosis, whereas the four other patients were all alive with stable disease at the last clinical follow-up (at 9 months, 1 year and 7 years) without adjuvant therapy. We demonstrate in this first series of midline GGs that the H3 K27M mutation can occur in association with the BRAF V600E mutation in grade I glioneuronal tumors. Despite the presence of H3 K27M mutations, these cases should not be graded and treated as grade IV tumors because they have a better spontaneous outcome than classic diffuse midline H3 K27M-mutant glioma. These data suggest that H3 K27M cannot be considered a specific hallmark of grade IV diffuse gliomas and highlight the importance of integrated histomolecular diagnosis in paediatric brain tumors.

Gangliocytoma Presenting With Tacrolimus Neurotoxicity in a Renal Transplant Recipient: Case Report

Tacrolimus is a widely used macrolide immunosuppressant in transplant surgery, with mild and major neurologic side effects. A 21-year-old woman had undergone preemptive transplantation of a kidney from her mother. On the 1st postoperative day, the patient had headache, nausea, vomiting, and agitation. Magnetic resonance imaging (MRI) of the brain showed hyperintensity and a lesion in the right mesial temporal lobe. After we switched from tacrolimus to cyclosporine, the symptoms regressed. Persistence of the lesion, confirmed by repeated MRI, required that the patient be operated on. Pathologic examination showed the gangliocytoma, a rare brain tumor. Our case shows that preexisting brain lesions may cause tacrolimus-induced neurotoxicity in the early postoperative period.

Genetic Characterization of a Multifocal Ganglioglioma Originating Within the Spinal Cord

BACKGROUND

Gangliogliomas are rare, low-grade intra-axial tumors that exhibit both neuronal and glial components. Although the vast majority present as an intracranial lesion, a rare subset exist as isolated lesions of the spinal cord. Gangliogliomas have also been shown to harbor mutations in the p53 tumor suppressor gene and BRAF oncogene. Previous studies in ganglioglioma have correlated p53 mutations with histologic transformation and BRAF mutations with worse prognosis.

CASE DESCRIPTION

In this report, we describe a 35-year-old female who presented with multifocal ganglioglioma, involving both the conus medullaris and filum terminale. The dominant lesion in the filum terminale was resected, which revealed World Health Organization I grade, p53 mutant, and BRAF wildtype status. Our study documents the first report of a multifocal ganglioglioma, originating within the spinal cord.

CONCLUSIONS

Importantly, this case contradicts previous reports of p53 and BRAF mutations portending worsened tumor behavior and prognosis and demonstrates that further studies are needed to delineate the role of genetic characterization in the biologic understanding and management of gangliogliomas.

Clinical, Imaging, Histopathological and Molecular Characterization of Anaplastic Ganglioglioma

Anaplastic ganglioglioma (AGG) is a rare and malignant variant of ganglioglioma. According to the World Health Organization classification version 2016, their histopathological grading criteria are still ill-defined. The aim of the present study was to assess the clinical, imaging, histopathological, and molecular characteristics and outcomes of AGGs in a large consecutive and retrospective adult and pediatric case series. Eighteen patients with AGGs (13 adults and 5 children) were identified (14 de novo and 4 secondary) from a cohort of 222 gangliogliomas (GG) (8%) treated at our institution between 2000 and 2015. AGGs represented a very aggressive disease with poor outcome (median progression-free survival, 10 months; median overall survival, 27 months). They were located in the temporal lobe only in 22% and presented with seizures (44%) or increased intracranial pressure (44%) at diagnosis. Concerning histopathological and molecular data, they shared morphological characteristics and BRAF V600E mutation (39%) with their benign counterparts but also showed hTERT promoter mutation (61%), p53 accumulation (39%), ATRX loss (17%), or p.K27M H3F3A mutation (17%). AGGs are malignant neoplasms requiring aggressive oncological treatment. In the perspective of targeted therapies, AGGs should be screened for BRAF V600E, hTERT, ATRX, and mutations of histone genes.

A national perspective of adult gangliogliomas

Gangliogliomas (GG) are rare tumors of the nervous system. Patient characteristics and clinical outcomes of low and high-grade GG have been difficult to elucidate in the adult population. This study aims to further elaborate on GG treatment and overall survival utilizing a larger cohort than previously published. The USA National Cancer Database was utilized to evaluate adult (age 18years and older) patients diagnosed with GG between 2004 and 2006. Descriptive statistics and Kaplan-Meier overall survival estimates were provided. A total of 198 adult GG patients were diagnosed between 2004 and 2006. Of these, 181 (91.4%) were low-grade and 17 (8.6%) high-grade GG. Overall, the median age was 36years; approximately 50% of patients were female, and 86.5% Caucasian. Most patients (59%) had near/gross total resection. Radiation and chemotherapy were prescribed in 18 (9.1%) and 11 (5.7%) patients, respectively. Radiation (64.7% versus 3.9%, p<.0001) and chemotherapy (47.1% versus 1.7%, p<.0001) were more frequently given to patients with high-grade tumors than low-grade. The median overall survival of high-grade GG was 44.4months (95% confidence interval [CI]: 10.5-92.5) while the corresponding estimate for low-grade tumors was not reached. Older age (hazard ratio [HR] 1.72, 95% CI: 1.26-2.34) and high tumor grade (HR 3.91, 95% CI: 1.43-10.8) were found to be associated with poor survival. Adult GG have a temporal lobe predilection and overall gross total resection rate of 59%. Older patients with high-grade tumors had an increased hazard of mortality. High-grade GG were significantly more likely to be treated with radiation therapy and chemotherapy.

Rare glial tumors

This chapter describes the epidemiology, pathology, molecular characteristics, clinical and neuroimaging features, treatment, outcome, and prognostic factors of the rare glial tumors. This category includes subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma, astroblastoma, chordoid glioma of the third ventricle, angiocentric glioma, ganglioglioma, desmoplastic infantile astrocytoma and ganglioma, dysembryoplastic neuroepithelial tumor, papillary glioneuronal tumor, and rosette-forming glioneuronal tumor of the fourth ventricle. Many of these tumors, in particular glioneuronal tumors, prevail in children and young adults, are characterized by pharmacoresistant seizures, and have an indolent course, and long survival following surgical resection. Radiotherapy and chemotherapy are reserved for recurrent and/or aggressive forms. New molecular alterations are increasingly recognized.

Recurrent ganglioglioma in adults treated with BRAF inhibitors

Thirteen adult patients with temozolomide, surgery and radiation refractory ganglioglioma were screened for the BRAF V600E mutation. Three (23%) were found positive for the presence of the BRAF mutation and were treated with the BRAF inhibitor dabrafenib. Dabrafenib was well tolerated with no grade 3 or higher toxicity. The median number of cycles was 7 (a cycle was defined as 1 month of daily dabrafenib) and best response was stable disease in two patients and a partial response in one patient. Median progression-free survival was 7 months with a range of 4-10 months.

Landscape of chromosomal copy number aberrations in gangliogliomas and dysembryoplastic neuroepithelial tumours

AIM

Gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumours (DNTs) represent the most common histological entities within the spectrum of glioneuronal tumours (GNTs). The wide variability of morphological features complicates histological classification, including discrimination from prognostically distinct diffuse low-grade astrocytomas (AIIs). This study was performed to increase our understanding of these tumours.

METHODS

We studied chromosomal copy number aberrations (CNAs) by genome-wide sequencing in a large cohort of GNTs and linked these to comprehensive histological analysis and clinical characteristics. One hundred fourteen GNTs were studied: 50 GGs and 64 DNTs. Also, a data set of CNAs from 38 diffuse AIIs was included.

RESULTS

The most frequent CNAs in both GGs and DNTs were gains at chromosomes 5 and 7, often concurrent, and gain at chromosome 6. None of the CNAs was linked to histological subtype, immunohistochemical features or to clinical characteristics. Comparison of AIIs and diffuse GNTs revealed that gain at whole chromosome 5 is only observed in GNTs. CNA patterns indicative of chromothripsis were detected in three GNTs.

CONCLUSION

We conclude that GNTs with diverse morphologies share molecular features, and our findings support the need to improve classification and differential diagnosis of tumour entities within the spectrum of GNTs, as well as their distinction from other gliomas.