Intracranial ganglioglioma: preoperative characteristics and oncologic outcome after surgery

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.

Nomograms Based on MRI Radiomics for Differential Diagnosis and Predicting BRAFV600E Expression in Pleomorphic Xanthoastrocytoma and Ganglioglioma

RATIONALE AND OBJECTIVES

This study was designed to investigate the value of nomograms based on MRI radiomics and clinical semantic features in identifying pleomorphic xanthoastrocytoma (PXA) and ganglioglioma (GG) as well as predicting BRAFV600E expression.

MATERIALS AND METHODS

This study included 265 patients histologically diagnosed with PXA (n = 113) and GG (n = 152). T1WI, T2WI, and CET1 sequences were utilized to extract radiomics features. Univariate analysis, Spearman correlation analysis, and the least absolute shrinkage and selection operator were used for dimensionality reduction and feature selection. Following this, logistic regression was utilized to establish the radiomics model. Univariate and multivariate analyses of clinical semantic features were applied, and clinical models were constructed. The nomograms were established by merging radiomics and clinical features. Furthermore, ROC curve analysis was used for examining the model performance, whereas the decision curve analysis (DCA) examined the clinical utility of the nomograms.

RESULTS

Nomograms achieved the best predictive efficacy compared to clinical and radiomics models alone. Concerning the differentiation between PXA and GG, the area under the curve (AUC) values of the nomogram were 0.879 (0.828-0.930) and 0.887 (0.805-0.969) for the training and testing cohorts, respectively. For predicting BRAFV600E expression, the AUC values of the nomogram were 0.873 (0.811-0.936) and 0.851 (0.740-0.963) for the training and testing cohorts, respectively. DCA confirmed the clinical utility of the nomograms.

CONCLUSION

Nomograms based on radiomics and clinical semantic features were noninvasive tools for differential diagnosis of PXA and GG and predicting BRAFV600E expression, which may be helpful for assessing patient prognosis and developing individualized treatment strategies.

Radiological and clinical outcomes of stereotactic radiosurgery for gangliogliomas: an international multicenter study

OBJECTIVE

The optimal treatment for recurrent and residual gangliogliomas remains unclear. The aim of this study was to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) in the management of patients with recurrent or residual intracranial ganglioglioma.

METHODS

This retrospective multicenter study involved patients managed with SRS for ganglioglioma. The study endpoints included local tumor control and tumor- or SRS-related neurological morbidity following treatment. Factors associated with tumor progression and neurological morbidity were also analyzed.

RESULTS

The cohort included 20 patients (11 males [55%]) with a median age of 24.5 (IQR 14) years who had been managed with SRS for ganglioglioma. Five-year radiological progression-free survival was 85.6%. After SRS, 2 patients (10%) experienced transient neurological deterioration. At a median clinical follow-up of 88.5 (IQR 112.5) months, 1 patient (5%) experienced seizure worsening and 1 (5%) required further resection of the tumor because of radiological progression. No mortality was noted in this series.

CONCLUSIONS

SRS appears to be a safe and effective treatment option for surgically inaccessible, recurrent, and residual gangliogliomas. In this series, the 5-year progression-free survival rate after SRS was 85.6%. Gross-total resection remains the primary treatment of choice for patients with newly diagnosed or recurrent ganglioglioma. SRS may be considered for patients unfit for surgery and those with surgically inaccessible newly diagnosed, residual, and recurrent lesions.

NTRK3 gene fusion in an adult ganglioglioma: illustrative case

BACKGROUND

Gangliogliomas are well-differentiated, slow-growing glioneuronal neoplasms frequently reported to harbor upregulating alterations in the mitogen-activated protein kinase pathway, particularly serine–threonine protein kinase B-RAF alterations. Fusions involving neurotrophin tyrosine receptor kinase (NTRK) genes have rarely been reported in ganglioglioma. Similarly, echinoderm microtubule-associated protein-like (EML) 4 gene fusion has been described in lung cancer, but none has been reported in ganglioglioma.

OBSERVATIONS

This report discusses the care of a 72-year-old man presenting with medication-refractory, left-sided focal seizures who was found to have a nongadolinium-enhancing, T2-hyperintense, right frontoparietal lesion. The patient received resection, and histological analysis found a World Health Organization grade I ganglioglioma, with genetic analysis demonstrating an EML4-NTRK3 gene fusion protein.

LESSONS

To our knowledge, this is the first report of an NTRK3 fusion, EML4-NTRK3, in an adult ganglioglioma, which is otherwise mostly associated with BRAF alterations and activation of the mitogen-activated protein kinase signaling pathway. Further studies are needed to elucidate the function of the resultant fusion protein and determine whether it may serve as a future therapeutic target.

Lentivirus vector‑mediated genetic manipulation of oncogenic pathways induces tumor formation in rabbit brain

Translation of promising experimental therapies from rodent models to clinical success has been complicated as the novel therapies often fail in clinical trials. Existing rodent glioma models generally do not allow for preclinical evaluation of the efficiency of novel therapies in combination with surgical resection. Therefore, the aim of the present study was to develop a larger animal model utilizing lentivirus vector‑mediated oncogenic transformation in the rabbit brain. Lentiviruses carrying constitutively active AKT and H‑Ras oncogenes, and p53 small interfering (si)RNA were introduced into newborn rabbit neural stem cells (NSCs) and intracranially implanted into rabbits' brains to initiate tumor formation. In one of the ten rabbits a tumor was detected 48 days after the implantation of transduced NSCs. Histological features of the tumor mimic was similar to a benign Grade II ganglioglioma. Immunostaining demonstrated that the tissues were positive for AKT and H‑Ras. Strong expression of GFAP and Ki‑67 was also detected. Additionally, p53 expression was notably lower in the tumor area. The implantation of AKT, H‑Ras and p53 siRNA transduced NSCs for tumor induction resulted in ganglioglioma formation. Despite the low frequency of tumor formation, this preliminary data provided a proof of principle that lentivirus vectors carrying oncogenes can be used for the generation of brain tumors in rabbits. Moreover, these results offer noteworthy insights into the pathogenesis of a rare brain tumor, ganglioglioma.

Radiohistogenomics of pediatric low-grade neuroepithelial tumors

PURPOSE

In addition to histology, genetic alteration is now required to classify many central nervous system (CNS) tumors according to the most recent World Health Organization CNS tumor classification scheme. Although that is still not the case for classifying pediatric low-grade neuroepithelial tumors (PLGNTs), genetic and molecular features are increasingly being used for making treatment decisions. This approach has become a standard clinical practice in many specialized pediatric cancer centers and will likely be more widely practiced in the near future. This paradigm shift in the management of PLGNTs necessitates better understanding of how genetic alterations influence histology and imaging characteristics of individual PLGNT phenotypes.

METHODS

The complex association of genetic alterations with histology, clinical, and imaging of each phenotype of the extremely heterogeneous PLGNT family has been addressed in a holistic approach in this up-to-date review article. A new imaging stratification scheme has been proposed based on tumor morphology, location, histology, and genetics. Imaging characteristics of each PLGNT entity are also depicted in light of histology and genetics.

CONCLUSION

This article reviews the association of specific genetic alteration with location, histology, imaging, and prognosis of a specific tumor of the PLGNT family and how that information can be used for better imaging of these tumors.

Diagnosis and Therapeutic Management of Ventricular Gangliogliomas: An Illustrated Review

BACKGROUND

Gangliogliomas (GGs) are extremely rare benign neoplasms frequently located within the temporal lobe that usually present with seizures. GGs growing predominantly within the ventricular system (VGGs) are even more infrequent, so definite conclusions concerning their diagnosis and therapeutic management are lacking.

METHODS

A retrospective review of case reports of VGGs was performed from the introduction of modern imaging techniques, including 4 new illustrative cases treated in our department.

RESULTS

Thirty-four cases were collected. Ages ranged from 10 to 71 years (mean, 26.62 years), and 55.9% were male. Most patients developed symptoms related to high intracranial pressure. The lateral ventricles were predominantly involved (58.8%). Obstructive hydrocephalus was observed in 54.5% of patients. Cystic degeneration and calcification were frequently observed. Surgical treatment was carried out in all cases. Morbidity and mortality were 17.6% and 2.9%, respectively. Gross total tumor resection was achieved in 64.5% of patients. Four patients experienced tumor dissemination along the neural axis. More than 90% of patients maintained a good functional status at last follow-up.

CONCLUSIONS

Despite their low incidence, a diagnosis of VGGs should be considered in young male adults who progressively develop intracranial hypertension, caused by a ventricular mass showing signs of cystic degeneration and calcification. Maximal and safe surgical resection represents the gold standard for the treatment of symptomatic VGGs, although total removal is frequently precluded by difficulties in defining appropriate tumor boundaries. Adjuvant radiotherapy should be considered if an incomplete resection was carried out, especially in World Health Organization grade III neoplasms.

Giant Cerebellar Ganglioglioma Mimicking a Pilocytic Astrocytoma

A benign brain tumor, called a ganglioglioma (GG), can sometimes be found in the cerebrum. We describe an unusual pediatric case of GG in the cerebellum in this article. An 11-year-old male patient had a headache and epilepsy disorder. The head magnetic resonance imaging results revealed a giant cyst with an enhancing mural nodule in the right cerebellar hemisphere that flattened the fourth ventricle. Pilocytic astrocytoma was the provisional diagnosis based on clinical and imaging details. After radical mass eradication, a GG was demonstrated through histopathological analysis. Even though GG is an uncommon tumor, it should be included in the differential diagnosis for a cerebellar mass with both cystic and solid components in children.

[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.

Glioneuronal tumors: clinicopathological findings and treatment options

Glioneuronal tumors are very rare CNS neoplasms that demonstrate neuronal differentiation, composed of mixed glial and neuronal cells. The majority of these lesions are low grade and their correct classification is crucial in order to avoid misidentification as ‘ordinary’ gliomas and prevent inappropriate aggressive treatment; nevertheless, precise diagnosis is a challenge due to phenotypic overlap across different histologic subtype. Surgery is the standard of therapeutic approach; literature concerning the benefit of adjuvant treatments is inconclusive and a globally accepted treatment of recurrence does not exist. Targetable mutations in the genes BRAF and FGFR1/2 are recurrently found in these tumors and could take a promising role in future treatment management.

Clinical Relevance of Interictal Spikes in Tumor-Related Epilepsy: An Electrocorticographic Study

Background and Purpose

Although some surgeons utilize interictal spikes recorded via electrocorticography (ECoG) when planning extensive peritumoral resection in patients with tumor-related epilepsy, the association between interictal spikes and epileptogenesis has not been fully described. We investigated whether the resection of interictal spikes recorded by ECoG is associated with more favorable surgical outcomes in tumor-related epilepsy.

Methods

Of 132 patients who underwent epilepsy surgery for tumor-related epilepsy from 2006 to 2013, seven patients who underwent extraoperative ECoG were included in this study. In each patient, ECoG interictal spike sources were localized using standardized low-resolution brain electromagnetic tomography and were co-registered into a reconstructed brain model. Correspondence to the resection volume was estimated by calculating the percentage of interictal spike sources in the resection volume.

Results

All patients achieved gross total resection without oncological recurrence. Five patients achieved favorable surgical outcomes, whereas the surgical outcomes of two patients were unfavorable. Correspondence rates to the resection volume in the favorable and unfavorable surgical outcome groups were 44.6%±27.8% and 43.5%±22.8%, respectively (p=0.96). All patients had interictal spike source clusters outside the resection volume regardless of seizure outcome.

Conclusions

In these cases of tumor-related epilepsy, the extent of the resection of ECoG interictal spikes was not associated with postoperative seizure outcomes. Furthermore, the presence of interictal spike sources outside of the resection area was not related to seizure outcomes. Instead, concentrating more on the complete removal of the brain tumor appears to be a rational approach.

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.

Ganglioglioma of the adenohypophysis mimicking pituitary adenoma: A case report and review of the literature

INTRODUCTION

Ganglioglioma is a generally benign tumor, mostly occurring in patients <30 years old. Temporal lobe is most frequently involved. Up to now, only 3 cases were reported of ganglioglioma in the pituitary gland, all being confined to the neurohypophysis. Here, we are the first to report an adenohypophysis ganglioglioma.

CASE PRESENTATION

A 43-year-old woman presented with chronic headache was referred to our hospital. Magnetic resonance imaging (MRI) indicated pituitary adenoma. Endoscopic transnasal transsphenoidal surgery was performed. The tumor was rich in blood supply, with tough texture, therefore only subtotal resection was conducted. Pathology analysis revealed an adenohypophysial tumor composed of dysplastic ganglion cells and neoplastic glial cells collided with nonspecific hyperplasia of pituitary cells. Immunohistochemistry revealed positive staining of synaptophysin, glial-fibrillary acidic protein, and CD34. The results were consistent with the diagnosis of ganglioglioma. After the surgery the patient recovered well except developing cerebrospinal fluid rhinorrhea, which was controlled by lumbar drainage. MRI 6 months later did not show any sign of progression.

CONCLUSION

According to the findings of our case, concerns should be raised considering ganglioglioma as a differential diagnosis of mass located in the sellar region. Furthermore, an ideal management strategy for pituitary ganglioglioma is not known; therefore, more cases and long-term follow-up are needed to enrich our knowledge of the diagnosis, treatment, and prognosis of this rare intracranial lesion.

Ganglioglioma in children and young adults: single institution experience and review of the literature

BACKGROUND

Ganglioglioma (GG) is a rare mixed glial-neuronal neoplasm accounting for 0.5-5% of all pediatric central nervous system (CNS) tumors. Rarity of this tumor has precluded defining robust treatment guidelines. This retrospective study evaluates the prognostic factors and outcomes of this rare neoplasm.

PATIENTS AND METHODS

Retrospective analysis of 55 patients with GG was conducted to describe clinical findings, and outcomes. Kaplan-Meier survival and Cox-regression analyses were performed to assess the overall survival (OS) and progression-free survival (PFS).

RESULTS

The mean age at diagnosis was 11.8 years (range 1-21 years) with a median follow-up period of 9.5 years. 53 patients (92.7%) had low grade GG and 2 patients had anaplastic GG. 25 patients had tumor progression, whose median PFS was 12 years. Six patients with low grade GG progressed to a higher grade, with median survival of 9.1 month after transformation. The 5 and 10 year PFS were 65 and 57%, respectively. The 5 and 10 year OS was 96 and 86% respectively. 8 of the 19 (42%) samples tested demonstrated positivity for the BRAF V600E mutation. Multivariate Cox regression analyses showed location and extent of resection were significant factors for PFS and presence of metastatsis attained significance for OS.

CONCLUSION

This is the one of the largest retrospective study of pediatric GG. Identifying clinical variables, which could stratify these tumors into low- and high-risk groups might help to profile a risk-based therapeutic strategy. Collaborative multiinstitutional prospective studies are warranted to delineate treatment consensus and investigate prognostic factors.

Natural course and prognosis of anaplastic gangliogliomas: a multicenter retrospective study of 43 cases from the French Brain Tumor Database

Background

Anaplastic gangliogliomas (GGGs) are rare tumors whose natural history is poorly documented. We aimed to define their clinical and imaging features and to identify prognostic factors.

Methods

Consecutive cases of anaplastic GGGs in adults prospectively entered into the French Brain Tumor Database between March 2004 and April 2014 were screened. After diagnosis was confirmed by pathological review, clinical, imaging, therapeutic, and outcome data were collected retrospectively.

Results

Forty-three patients with anaplastic GGG (median age, 49.4 y) from 18 centers were included. Presenting symptoms were neurological deficit (37.2%), epileptic seizure (37.2%), or increased intracranial pressure (25.6%). Typical imaging findings were unifocal location (94.7%), contrast enhancement (88.1%), central necrosis (43.2%), and mass effect (47.6%). Therapeutic strategy included surgical resection (95.3%), adjuvant radiochemotherapy (48.8%), or radiotherapy alone (27.9%). Median progression-free survival (PFS) and overall survival (OS) were 8.0 and 24.7 months, respectively. Three- and 5-year tumor recurrence rates were 69% and 100%, respectively. The 5-year survival rate was 24.9%. Considering unadjusted significant prognostic factors, tumor midline crossing and frontal location were associated with shorter OS. Temporal and parietal locations were associated with longer and shorter PFS, respectively. None of these factors remained statistically significant in multivariate analysis.

Conclusions

We report a large series providing clinical, imaging, therapeutic, and prognostic features of adult patients treated for an intracerebral anaplastic GGG. Our results show that pathological diagnosis is difficult, that survivals are only slightly better than for glioblastomas, and that complete surgical resection followed with adjuvant chemoradiotherapy offers longer survival.

BRAF V600E mutation is a significant prognosticator of the tumour regrowth rate in brainstem gangliogliomas

BRAF V600E mutations are progression factors in paediatric low-grade gliomas. Furthermore, a high percentage of paediatric brainstem gangliogliomas have BRAF V600E mutations. However, their clinical significance, including possible connections between the biomarkers and ganglioglioma's clinical features, especially a brainstem counterpart, is unclear. To identify potential molecular features predictive of brainstem ganglioglioma's clinical outcomes, a retrospective cohort of 28 World Health Organization (WHO) grade I brainstem gangliogliomas was analysed for BRAF V600E, IDH1 R132H, and IDH2 R172K mutations, TERT C228T/C250T promoter mutation, H3F3A K27M mutation and MGMT methylation. The volume of tumours was calculated accurately by using 3D Slicer software. The clinical data of these patients were retrospectively analysed. In tumours with BRAF V600E mutations, the tumour regrowth rate was significantly faster than that of the wild type group (p=0.001). Moreover, the BRAF V600E mutant group had shorter progression-free survival (PFS) compared with wild type (p=0.012). On multivariate analysis, no factor was found to be an independent prognostic factor; however, tumours with faster regrowth rates had a strong trend towards an increased risk for shorter PFS (HR=1.027, p=0.056). No statistical analysis could be performed to evaluate factors affecting overall survival (OS). These data suggest that BRAF V600E can predict the regrowth rate of brainstem gangliogliomas after microsurgery, and a BRAF V600E-targeted therapeutic may be a promising early intervention measure for patients who harbour BRAF V600E mutation after microsurgery.

Discrepancy between radiological and histological findings in ganglioglioma of the optic chasm: Case report

BACKGROUND

Gangliogliomas involving the optic nerve or chiasm are extremely rare tumors, which can be confused radiologically with other neoplasms. α-[N-methyl-¹¹C]-methylaminoisobutyric acid (¹¹C-MeAIB) is a new artificial amino acid positron emission tomography (PET) tracer, which is metabolically more stable in vivo and may be more specific for tumors than ¹¹C-methionine. However, the utility of ¹¹C-MeAIB PET in the diagnosis of brain tumors has not yet been reported.

CASE DESCRIPTION

A 26-year-old man presented with visual field defects and headache, and magnetic resonance imaging demonstrated a suprasellar mass involving the optic chiasm. A biopsy and partial tumor resection were performed via an interhemispheric approach. We diagnosed the tumor as ganglioglioma (WHO grade I) involving the optic chiasm. Although this lesion was histologically benign, ¹¹C-MeAIB PET, 2-deoxy-2-[¹⁸F] fluoro-D-glucose (¹⁸F-FDG) PET and proton magnetic resonance spectroscopy indicated malignant features.

CONCLUSION

The discrepancy between radiological and histological findings implies that this new amino acid tracer PET may have a limitation in the diagnosis of gangliogliomas. Although further study is necessary, gangliogliomas should be included in the differential diagnosis of suprasellar tumors, even if PET findings show malignant features.

Adult Brain Tumors and Pseudotumors: Interesting (Bizarre) Cases

Some brain tumors results are interesting due to their rarity at presentation and overwhelming imaging characteristics, posing a diagnostic challenge in the eyes of any experienced neuroradiologist. This article focuses on the most important features regarding epidemiology, location, clinical presentation, histopathology, and imaging findings of cases considered "bizarre." A review of the most recent literature dealing with these unusual tumors and pseudotumors is presented, highlighting key points related to the diagnosis, treatments, outcomes, and differential diagnosis.

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.

Brainstem gangliogliomas: prognostic factors, surgical indications and functional outcomes

To explore the prognostic factors and discuss the surgical indications of brainstem gangliogliomas. Twenty-one patients with brainstem ganglioglioma were surgically treated at our hospital between 2006 and 2014. The clinical, radiological, operative, and pathological findings of these patients were retrospectively reviewed. The 3-years overall survival and event-free survival (EFS) rates were 90.5 % and 68.4 %, respectively. Four patients (4/18, 22 %) experienced a recurrence with a mean recurrence-free survival of 5.5 months and a mean follow-up of 37 months. Three patients died of surgery-related complications. Three growth patterns were identified: exophytic (6/21), intrinsic (2/21), and endo-exophytic (13/21). Eight patients (8/15, 53 %) harbored a BRAF V600E mutation. All recurrent tumors were endo-exophytic, and except the one without molecular information, were BRAF V600E mutants. A Cox hazard proportion ratio model was used to identify factors influencing EFS, including sex, age, location, growth patterns, extent of resection (EOR), and BRAF V600E mutation status. On univariate analysis, none of these factors reached statistical significance. Among them, EOR and growth patterns were strongly associated with each other (Fisher's exact test, P < 0.01). A multivariate analysis demonstrated that growth patterns were the only factor associated with EFS (P = 0.02; HR 49.05; 95 % CI 1.76-1365.13). Growth patterns may be useful to select surgery candidates and predict prognosis for patients with brainstem gangliogliomas. BRAF V600E was frequently present and appeared to be associated with shorter recurrence-free survival. Studies on BRAF V600E-targeted therapy for patients with high surgical risks are needed.

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.

Ganglioglioma: Single-institutional experience of 24 cases with review of literature

Background:

Ganglioglioma is a common seizure associated tumor. The goal of this study was to observe the postoperative outcome in patients with gangliogliomas.

Material and Methods:

A total 24 patients with gangliogliomas who underwent surgery at our institute from 2008 to 2011 were included. There were 13 males (54%) in our study. A retrospective analysis for the demographic profile, surgery and outcome was performed using STATA software. Literature on this subject was also reviewed, MEDLINE and PUBMED databases were searched.

Observations:

Sixteen patients presented with signs and symptoms of raised intracranial pressure and 12 patients had seizure disorder. Average age at surgery was 20 years (range 7-50 years). Twelve each were located in the temporal lobe and extra-temporal location. Intra-operative electrocorticography (ECoG) alone in three and image guidance alone were used in two patients, respectively. Both ECoG and image guidance were used in one patient and none of them was used in 18 patients. Gross total resection was achieved in 17 patients. After a mean follow-up of 1.6 years (range 3 months to 2.5 years), out of 12 patients with preoperative seizures, 10 (83.3%) were seizure free (Engel class-I) and 2 (16.6%) belonged to Engel class-II. None of the factors, including age at surgery, seizure duration prior to surgery, type of seizures, use of intra-operative ECoG and image guidance, extent of tumor resection, and surgical strategy proved to have significant correlation with postoperative seizure outcome.

Conclusions:

Surgical treatment is effective and safe for patients with gangliogliomas. Neither intra-operative ECoG nor image guidance necessarily leads to better seizure control, although they are useful adjunct for achieving safe and complete tumor resection.

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.

Atypical pediatric ganglioglioma is common and associated with a less favorable clinical course

OBJECT Ganglioglioma (GG) is commonly recognized as a low-grade tumor located in the temporal lobe, often presenting with seizures. Most are amenable to complete resection and are associated with excellent oncological outcome. The authors encountered several GGs in various locations, which seem to have a less favorable clinical course than GGs in the temporal lobe. METHODS The authors performed a single-center retrospective review of all children with a histological diagnosis of GG who were treated at Children's Hospital Colorado between 1997 and 2013. Each tumor was categorized by 2 pediatric neuroradiologists as typical or atypical based on preoperative MRI appearance. Typical lesions were cortically based, within a single cerebral lobe, well-circumscribed, and solid or mixed solid/cystic. The treatment and clinical course of each patient was analyzed. RESULTS Thirty-seven children were identified, with a median age at presentation of 8.2 years and median follow-up of 38.0 months. Eighteen tumors (48.6%) were typical and 19 (51.4%) were atypical. All typical lesions presented with seizures, whereas no atypical lesions did so. Sixteen (88.9%) typical lesions were located in the temporal lobe. In the atypical group, tumor location was variable, including 11 (57.9%) in the brainstem. Death during follow-up was statistically more common in the atypical group (31.6% vs 0%, p = 0.02). Gross-total resection (GTR) was achieved for 15 of 16 typical tumors (93.8%), compared with 3 atypical tumors (15.8%, p < 0.0001). Presentation with seizure or non-brainstem location were each associated with survival (p = 0.02 and 0.004, respectively). The presence of mutation in BRAF exon 15 did not differ between the 2 groups. CONCLUSIONS Pediatric GG with typical imaging features is associated with excellent rates of GTR and overall survival. Atypical GG is commonly encountered, less amenable to GTR, and associated with a worse outcome. This may relate to anatomical or biological characteristics and merits further investigation.

Principles of radiation therapy

Although resection remains the mainstay in the treatment of gliomas, microscopically complete resection of most central nervous system tumors remains challenging, and is, in fact, rarely accomplished. Considering their invasive nature, gross total resections to clearly negative margins often do or would require removal or transection of functional brain, with likely serious neurologic deficits. Consequently, radiotherapy has emerged as an indispensable component of therapy. It is delivered primarily by external-beam radiotherapy or brachytherapy techniques. Herein, we present the biologic principles, techniques, and applications of radiotherapy in glioma treatment today.

Pediatric infratentorial ganglioglioma

PURPOSE

Pediatric infratentorial gangliogliomas are exceedingly rare tumors; thus, the factors affecting their outcome are poorly understood and their optimal management has still to be defined.

METHODS

We reviewed the literature on pediatric gangliogliomas with a focus on those located in the posterior fossa to study treatment and outcome data. We added to this review some of our clinical cases.

RESULTS

We found 100 and 80 cases of brainstem and cerebellar pediatric ganglioglioma, respectively, in our literature review. The surgical management varied from biopsy to gross total resection, and adjuvant treatment was given after incomplete resection or at time of progression. A gross total resection should be attempted to remove the contrast enhancing part of the tumor, which may be possible in most of the cerebellar gangliogliomas and some of the brainstem lesions. The cervicomedullary ganglioglioma seems to be the most infiltrative and least amenable to complete resection. Chemotherapy has a limited role and BRAF mutation was reported in 38 to 54 % of cases. The use of radiotherapy exposes the patient to a risk of malignant transformation and should be reserved for unresectable tumors which progress.

CONCLUSION

Pediatric posterior fossa gangliogliomas are rare and challenging tumors due to their frequent infiltrative component involving the brainstem. To date, adjuvant therapy has a limited role that may evolve with time thanks to the use of targeted therapies against BRAF mutation. The surgical resection of well-defined contrast enhancing parts should be attempted even in staged surgeries and balanced with the risks of neurological deterioration.

Resection of cerebral gangliogliomas causing drug-resistant epilepsy: short- and long-term outcomes using intraoperative MRI and neuronavigation

OBJECT Cerebral gangliogliomas (GGs) are highly associated with intractable epilepsy. Incomplete resection due to proximity to eloquent brain regions or misinterpretation of the resection amount is a strong negative predictor for local tumor recurrence and persisting seizures. A potential method for dealing with this obstacle could be the application of intraoperative high-field MRI (iopMRI) combined with neuronavigation. METHODS Sixty-nine patients (31 female, 38 male; median age 28.5 ± 15.4 years) suffering from cerebral GGs were included in this retrospective study. Five patients received surgery twice in the observation period. In 48 of the 69 patients, 1.5-T iopMRI combined with neuronavigational guidance was used. Lesions close to eloquent brain areas were resected with the implementation of preoperative diffusion tensor imaging tractography and blood oxygenation level-dependent functional MRI (15 patients). RESULTS Overall, complete resection was accomplished in 60 of 69 surgical procedures (87%). Two patients underwent biopsy only, and in 7 patients, subtotal resection was accomplished because of proximity to critical brain areas. Excluding the 2 biopsies, complete resection using neuronavigation/iopMRI was documented in 33 of 46 cases (72%) by intraoperative imaging. Remnant tumor mass was identified intraoperatively in 13 of 46 patients (28%). After intraoperative second-look surgery, the authors improved the total resection rate by 9 patients (up to 91% [42 of 46]). Of 21 patients undergoing conventional surgery, 14 (67%) had complete resection without the use of iopMRI. Regarding epilepsy outcome, 42 of 60 patients with seizures (70%) became completely seizure free (Engel Class IA) after a median follow-up time of 55.5 ± 36.2 months. Neurological deficits were found temporarily in 1 (1.4%) patient and permanently in 4 (5.8%) patients. CONCLUSIONS Using iopMRI combined with neuronavigation in cerebral GG surgery, the authors raised the rate of complete resection in this series by 19%. Given the fact that total resection is a strong predictor of long-term seizure control, this technique may contribute to improved seizure outcome and reduced neurological morbidity.

Treatment and outcomes for gangliogliomas: a single-center review of 16 patients

Background

Ganglioglioma is a rare and slowly growing benign tumor. We investigated the outcomes of patients who underwent different combination treatments.

Methods

Between 1998 and 2012, 16 patients, including 11 men and 5 women, with a median age of 12.5 years (range, 2.5-65 years) were treated for intracranial gangliogliomas at our institution. The median follow-up period was 5.7 years (range, 48 days-15.6 years). Fifteen cases were included in the outcome assessment because one patient was lost to follow-up. Complete resection was achieved in 8 (53%) patients. Six (40%) patients underwent incomplete resection with or without adjuvant radiotherapy, and one patient with a brainstem tumor underwent only stereotactic biopsy.

Results

Gangliogliomas predominantly affected young (87.5%), male patients and most frequently presented with seizures (64%). Of eight patients who underwent complete resection, seven did not show recurrence, whereas only three of six with incomplete resection showed no recurrence. Four patients with recurrence received salvage treatments (two repeat surgeries and two radiosurgeries). A tumor control rate of 93% (14/15) was achieved at the last follow-up. No recurrence or malignant changes were observed after a median follow-up of 12 and 4.5 years in four patients who received gamma knife (GK) radiosurgery as adjuvant and salvage treatment.

Conclusion

Complete resection produced the best outcomes and incomplete resection followed by adjuvant or salvage treatments showed favorable outcomes. In patients who are not eligible for complete resection because of tumor location or potential neurologic deficits following surgery, GK radiosurgery should be considered for the treatment of residual or recurrent tumors.

Epilepsy related to developmental tumors and malformations of cortical development

Structural abnormalities of the brain are increasingly recognized in patients with neurodevelopmental delay and intractable focal epilepsies. The access to clinically well-characterized neurosurgical material has provided a unique opportunity to better define the neuropathological, neurochemical, and molecular features of epilepsy-associated focal developmental lesions. These studies help to further understand the epileptogenic mechanisms of these lesions. Neuropathological evaluation of surgical specimens from patients with epilepsy-associated developmental lesions reveals two major pathologies: focal cortical dysplasia and low-grade developmental tumors (glioneuronal tumors). In the last few years there have been major advances in the recognition of a wide spectrum of developmental lesions associated with a intractable epilepsy, including cortical tubers in patients with tuberous sclerosis complex and hemimegalencephaly. As an increasing number of entities are identified, the development of a unified and comprehensive classification represents a great challenge and requires continuous updates. The present article reviews current knowledge of molecular pathogenesis and the pathophysiological mechanisms of epileptogenesis in this group of developmental disorders. Both emerging neuropathological and basic science evidence will be analyzed, highlighting the involvement of different, but often converging, pathogenetic and epileptogenic mechanisms, which may create the basis for new therapeutic strategies in these disorders.

Intraventricular ganglioglioma prognosis and hydrocephalus: the largest case series and systematic literature review

BACKGROUND

Ganglioglioma is mostly found in cerebral parenchymal, and it is rarely located in the ventricular system. To date, ganglioglioma within the ventricular system has been reported in only 10 cases. Its prognosis and relationship with complicating hydrocephalus are unclear.

METHODS

A total of 7 cases with intraventricular ganglioglioma diagnosed by the surgical pathology examination from June 2004 to April 2011 in our center were retrospectively analyzed. The clinical data were collected from the clinical medical records, and the tumor site, size and basement of tumor were analyzed. Follow up was performed to obtain the clinical outcomes.

RESULTS

The 7 cases included 5 males and 2 females, with disease onset at 23.6 ± 14.9 years old. Epilepsy as the initial symptom was observed in 1 case. Reduced hearing, dizziness and weakness of both lower limbs were found in 1 case. Intracranial hypertension were detected in 5 cases, including 1 case complicating by decreased visual acuity. Tumors were located in the lateral ventricle in 5 cases, while 2 cases in the third ventricle. Hydrocephalus was observed in 5 cases, including 2 cases with severe hydrocephalus, and both underwent ventriculoperitoneal shunting. Total resection of tumors was performed in 5 cases, and 2 cases underwent gross total resection. The mean duration of follow-up was 28.7 months (8-90 months). Intracranial hypertension in all cases disappeared. Even radiotherapy post-surgery, one case with GTR relapsed 1 year later. However, the other 6 cases didn't relapse.

CONCLUSIONS

Ganglioglioma in ventricular system is extremely rare, mainly with the symptoms of intracranial hypertension or seizure. The degree of hydrocephalus is closely related to the site of tumor's basement. The prognosis is good after total resection. The patients with GTR should be followed-up.

Brainstem ganglioglioma in an infant: Case report and review of literature

Gangliogliomas are well differentiated, usually low grade, neuroepithelial tumors that comprise of neoplastic ganglion cells in combination with neoplastic glial cells. Occasionally, glial cells may show anaplastic features and are then labeled as anaplastic gangliogliomas. Most of the reported gangliogliomas are supratentorial tumors, predominantly in the temporal lobe. Brainstem location has been reported infrequently. As with cortically based gangliogliomas, though the primary treatment is resection, this is often not possible due to the eloquence of surrounding involved parenchyma. Here, we report a case of brainstem tumor in an 8-month-old child that was substantially resected and was histopathologically Grade 1 ganglioglioma. As per review of English literature, there has been no case of brainstem ganglioglioma reported in an infant (less than 1 year age). We discuss the surgical difficulties in the radical excision of such benign tumors and review literature on pediatric brainstem gangliogliomas.

Brainstem gangliogliomas: a retrospective series

OBJECT

The authors retrospectively analyzed data on brainstem gangliogliomas treated in their department and reviewed the pertinent literature to foster understanding of the preoperative characteristics, management, and clinical outcomes of this disease.

METHODS

In 2006, the authors established a database of treated lesions of the posterior fossa. The epidemiology findings, clinical presentations, radiological investigations, pathological diagnoses, management, and prognosis for brainstem gangliogliomas were retrospectively analyzed.

RESULTS

Between 2006 and 2012, 7 patients suffering from brainstem ganglioglioma were treated at the West China Hospital of Sichuan University. The mean age of the patients, mean duration of symptoms prior to diagnosis, and mean duration of follow-up were 28.6 years, 19.4 months, and 38.1 months, respectively. The main presentations were progressive cranial nerve deficits and cerebellar signs. Subtotal resection was achieved in 2 patients, and partial resection in 5. All tumors were pathologically diagnosed as WHO Grade I or II ganglioglioma. Radiotherapy and adjuvant chemotherapy were not administered. After 21-69 months of follow-up, patient symptoms were resolved or stable without aggravation, and MRI showed that the size of residual lesions was unchanged without progression or recurrence.

CONCLUSIONS

The diagnosis of brainstem ganglioglioma is of great importance given its favorable prognosis. The authors recommend the maximal safe resection followed by close observation without adjuvant therapy as the optimal treatment for this disease.

Delays in diagnosis of paediatric cancers: a systematic review and comparison with expert testimony in lawsuits

Delayed diagnosis of paediatric cancers is reported regularly and is a source of remorse for physicians and parents and a leading cause of malpractice claims. We did a systematic review of information about the distribution, determinants, and consequences of time to diagnosis of paediatric malignancies and compared these findings with those of court-appointed expert witnesses in malpractice claims in Canada and France. Time to diagnosis varied widely between tumour types in the 98 relevant studies (medians ranged from 2-260 weeks) without any significant decrease with time. Determinants of a long delay in diagnosis included older age, qualification of the first physician contacted, non-specific symptoms, histological type, and tumour localisation. Delayed diagnosis was associated with poor outcome for retinoblastoma and possibly for leukaemia, nephroblastoma, and rhabdomyosarcoma (data were insufficient for definitive conclusions). It was not associated with an adverse outcome for most CNS tumours, osteosarcoma or Ewing's sarcoma, and, paradoxically, was frequently associated with better outcomes than was short time to diagnosis in these cancers. A third of the court-appointed experts provided testimony concordant with the medical literature. The relations between delay in diagnosis and outcome are complex and probably depend more on tumour biology than on parental or medical factors.

Long-term outcomes for low-grade intracranial ganglioglioma: 30-year experience from the Mayo Clinic

OBJECT

Gangliogliomas comprise less than 1% of all brain tumors and occur most often in children. Therefore, there are a limited number of patients and data involving the use or role of adjuvant therapy after subtotal resections (STRs) of gangliogliomas. The objective of this study was to examine and review the Mayo Clinic experience of 88 patients with gangliogliomas, their follow-up, risk of recurrence, and the role of radiation therapy after STR or only biopsy.

METHODS

Eighty-eight patients with gangliogliomas diagnosed between 1970 and 2007 were reviewed. Data on clinical outcomes and therapy received were analyzed. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and overall survival.

RESULTS

The median age at diagnosis was 19 years. The median potential follow-up as of June 2008 was 142 months (range 9-416 months). Fifteen-year overall survival was 94%, median PFS was 5.6 years, with a 10-year PFS rate of 37%. Progression-free survival was dramatically affected by extent of initial resection (p < 0.0001).

CONCLUSIONS

This single-institution retrospective series of patients with gangliogliomas is unique given its large cohort size with a long follow-up duration, and confirms the excellent long-term survival rate in this group. The study also shows the importance of resection extent on likelihood of recurrence. Patients with gangliogliomas who undergo STR or biopsy alone have poor PFS. Radiation therapy may delay time to progression in patients with unresectable disease.

Temporal lobe gangliogliomas associated with chronic epilepsy: long-term surgical outcomes

OBJECTIVE

To review the clinical features and surgical outcome in patients with temporal lobe gangliogliomas associated with intractable chronic epilepsy.

METHODS

The Rush University Surgical Epilepsy Database was queried to identify patients with chronic intractable epilepsy who underwent resection of temporal lobe gangliogliomas at Rush University Medical Center. Medical records were reviewed for age of seizure onset, delay to referral for surgery, seizure frequency and characteristics, pre-operative MRI results, extent of resection, pathological diagnosis, complications, length of follow-up, and seizure improvement.

RESULTS

Fifteen patients were identified. Average duration between seizure onset and surgery was 14.3 years. Complex partial seizures were the most common presenting symptom. Detailed operative data was available for 11 patients - of these, 90.9% underwent complete resection of the amygdala and either partial or complete resection of the hippocampus, in addition to lesionectomy. Average follow-up was 10.4 years (range 1.6-27.5 years), with 14 patients improving to Engel's class I and one patient to Engel's class III. There were no recurrences, and permanent complications were noted in one patient.

CONCLUSIONS

Long-term follow-up of patients with temporal lobe gangliogliomas associated with chronic intractable epilepsy demonstrates excellent results in seizure improvement with surgery and increasingly low incidence of complications with improvements in microsurgical techniques.

Seizure outcome with surgical management of epileptogenic ganglioglioma: a study of 55 patients

BACKGROUND

Ganglioglioma is a common seizure-associated tumor, and some factors that may influence the postoperative seizure outcome have not been discussed or are controversial. The goal of this study was to observe the postoperative seizure outcome and the prognostic factors in patients with epileptogenic gangliogliomas.

METHODS

In this retrospective study, 55 patients with epileptogenic gangliogliomas underwent surgery. Postoperative seizure outcome during follow-up was recorded, and possible postoperative prognostic factors were analyzed.

RESULTS

There were 30 males and 25 females in our study. Twenty patients presented with chronic seizures. The mean age at surgery was 19.39 years, and the mean seizure duration prior to surgery was 4.47 years. Forty-three patients had complex partial seizures, 12 patients had simple partial seizures, and secondary generalization occurred in 18 patients. Brain magnetic resonance imaging (MRI) revealed 32 tumors were located in the temporal lobe and 23 in the extratemporal lobes. Intraoperative electrocorticography (ECoG) and intraoperative ultrasound (IOUS) were used in 42 and 11 patients, respectively. Gross total resection of the tumor was achieved in 42 patients (1 patient underwent reoperation), subtotal resection in 11, and partial resection in 2. Simple lesionectomy and tailored epilepsy surgery were performed in 24 and 31 patients, respectively. After a mean follow-up of 3.27 years, 48 patients, including 1 re-operated patient, were seizure free (Engel class I). None of the factors, including age at surgery, seizure duration prior to surgery, the type of seizures, use of intraoperative ECoG and IOUS, extent of tumor resection, and surgical strategy, proved to be significantly correlated with postoperative seizure outcome.

CONCLUSIONS

Surgical treatment is effective and safe for patients with epileptogenic gangliogliomas. Early surgical intervention is necessary for achieving early seizure control. Neither intraoperative ECoG nor IOUS necessarily leads to better seizure control, although the latter can be helpful in achieving complete tumor resection. Simple lesionectomy is sufficient for favorable postoperative seizure outcome.

Epileptogenic brain lesions in children: the added-value of combined diffusion imaging and proton MR spectroscopy to the presurgical differential diagnosis

PURPOSE

Focal cortical dysplasia (FCD), dysembryoplastic neuroepithelial tumors (DNTs), and gangliogliomas (GGs) share many clinical features, and the presurgical differential diagnosis of these lesions using conventional magnetic resonance imaging (MRI) is challenging in some cases. The purpose of this work was thus to evaluate the capacity of diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (MRS) to distinguish each lesion from the others.

METHODS

Seventeen children (mean age 9.0 ± 4.7 years), who had been referred for epilepsy associated with a brain tumor and operated, were selected. Preoperative MRI examinations were performed on a 1.5 T system and included anatomical images [T2-weighted, fluid-attenuated inversion recovery (FLAIR) and T1 pre- and post-injection images] as well as DWI and MRS [echo time (TE) = 30 and 135 ms]. Apparent diffusion coefficient (ADC) values were calculated in the lesion and healthy control. MRS relative quantification consisted in normalizing each metabolite by the sum (S) of all metabolites (S(TE=135 ms) = NAA+Cr+Cho; S(TE=30 ms) = NAA+Cr+Cho+Glx+mI). Univariate and multivariate analyses were performed in order to determine which criteria could differentiate the different epileptogenic brain lesions.

RESULTS

When taken alone, none of the MRI parameters was able to distinguish each disease from the others. Conventional MRI failed classifying two patients. When adding ADC to the linear discriminant analysis (LDA), one patient was still misclassified. Complete separation of the three groups was possible when combining conventional MRI, diffusion, and MRS either at long or short TE.

CONCLUSION

This study shows the added-value of multimodal MRI and MRS in the presurgical diagnosis of epileptogenic brain lesions in children.

Pediatric primary anaplastic ganglioglioma: a case report and review of the literature

Gangliogliomas with anaplastic features are classified as grade III tumors by the World Health Organization. The clinical course and optimal treatment of anaplastic gangliogliomas have not been well understood to date. We report a case of a primary pure anaplastic ganglioglioma in a 14-year-old male treated with surgery and radiotherapy, who is disease-free 6 years after the diagnosis. A review of primary pure anaplastic gangliogliomas in children (between 3 and 21 years of age) is presented. Gross total removal and focal radiotherapy with a total dose of 54 Gy are recommended. The addition of chemotherapy should be evaluated. Prospective studies are needed to identify an appropriate chemotherapy schedule and to define biological factors in order to select those patients with a poor prognosis, who are to be treated with a more aggressive therapy.