Neuropil-like islands are a possible pathogenetic link between glioblastoma and gangliocytoma/ganglioglioma in a case of synchronous bilateral brain tumors

Neuropil-like islands (NIs) are a histologic hallmark of glioneuronal tumors with neuropil-like islands (GTNIs), but GTNIs are presently not considered a homogeneous entity. The essence of GTNI is likely its glial component, and NIs are now considered aberrant neuronal differentiation or metaplasia. The case we report herein is a 41-year-old woman who was synchronously affected by two brain tumors: one was a glioblastoma (glioblastoma multiforme, GBM), of isocitrate dehydrogenase (IDH)-wild type, with NIs in the left parietal lobe, and the other was histologically a composite gangliocytoma (GC)/anaplastic ganglioglioma (GG) with NIs in the right medial temporal lobe. While both tumors were genetically wild type for IDH, histone H3, and v-raf murine sarcoma viral oncogene homolog B1 (BRAF), the former tumor, but not the latter, was mutated for telomerase reverse transcriptase promoter gene (TERT). A recent systematic study using DNA methylation profiling and next-generation sequencing showed that anaplastic GG separate into other WHO tumor types, including IDH-wild-type GBM. It suggested a diagnostic scheme where an anaplastic GG is likely an IDH-wild-type GBM if it is a BRAF wild type, IDH wild type, and TERT promoter mutant tumor. The likely scenario in this patient is that the GBM results from the progression of GC/anaplastic GG due to the superimposed TERT promoter mutation and the propagation of newly generated GBM cells in the contralateral hemisphere. A systematic analysis using DNA methylation profiling and next-generation sequencing was not available in this study, but the common presence of NIs histologically noted in the two tumors could support this scenario. Although a sufficient volume of molecular and genetic testing is sine qua non for the accurate understanding of brain tumors, the importance of histologic observation cannot be overemphasized.

High-Grade Temporal Ganglioglioma in an Older Adult Woman

Ganglioglioma (GG) is a WHO-grade 1 glioneuronal neoplasm. It is well differentiated with a slow-growing pattern and is composed of a combination of neoplastic ganglion and glial cells. Anaplastic ganglioglioma (AGG) is an extremely rare malignant variant of ganglioglioma, which is not included in the new WHO classification; however, the term is used to talk about gangliogliomas with data of malignancy. AGGs usually occur in children and young adults and are associated with high recurrence and mortality. The authors describe the case of a 62-year-old woman with AGG. She presented with cacosmia, vertigo, nausea, and focal-onset seizures with secondary generalization. Magnetic resonance imaging (MRI) revealed an intra-axial lesion in the left temporal lobe. She underwent microsurgical resection guided by electrocorticography (ECoG), and a diagnosis of AGG based on microscopic morphology and immunohistochemical analysis was obtained. She was discharged a few days after surgery with subtotal resection of the lesion, no additional neurological deficit, and adequate seizure control. AGG is a very rare and poorly studied entity. It is currently a controversial term used to refer to gangliogliomas with signs of malignancy. It occurs mainly in children and young adults with temporal lobe epilepsy. Total resection is the best prognostic factor, given the unknown efficacy of radiotherapy and chemotherapy. In our case, the patient was an adult woman with a subtotal resection followed by concomitant radiotherapy and chemotherapy, obtaining a mean survival similar to that reported in the literature, so it can be thought that there is a benefit obtained with chemotherapy and radiotherapy despite having performed a subtotal resection of the lesion. Further studies are needed to establish clear diagnostic criteria for AGG, and a multicenter database of AGGs is necessary for a better understanding of the pathology and to offer the best treatment and prognosis.

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.

A novel histopathological grading system for ganglioglioma

Gangliogliomas are central nervous system tumors located in the temporal lobe of young patients, frequently associated with epilepsy. In this paper, we propose a grading system based solely on histopathological criteria. We reevaluated all cases of ganglioglioma, atypical ganglioglioma, and anaplastic ganglioglioma diagnosed between 2011 and 2020 in the Pathology Department of the Emergency Clinical Hospital Bagdasar-Arseni, based on the type of glial mitoses, the number of neuronal and glial mitoses, presence of necrosis, microvascular proliferation, eosinophilic granular bodies, hypercellularity, presence and disposition of inflammatory infiltrate and atypical pleomorphism. Based on the proposed grading system, a score of 0–4 corresponded to a benign ganglioglioma, 5–9 to an atypical ganglioglioma, and 10–18 to an anaplastic ganglioglioma. The survival rates were 90% for benign ganglioglioma, 71.43% for atypical ganglioglioma, and 62.54% for anaplastic ganglioglioma. One case of benign ganglioglioma underwent a malignant transformation into anaplastic ganglioglioma, and recurrences were noticed in 28.57% of atypical ganglioglioma cases and 30.7% of all anaplastic gangliogliomas. The presence of rare glial mitoses and hypercellularity was correlated with mortality in cases of atypical ganglioglioma. We believe this histopathological scoring system could be used as a three-tier system to identify atypical ganglioglioma cases that are bound to have an aggressive course of evolution and require close follow-up. The other option would be to convert it to a two-tier grading system that can separate low-grade gangliogliomas from high-grade ones. The latter category can encompass both atypical and anaplastic ganglioglioma due to the high mortality of both entities.

Primary Anaplastic Ganglioglioma of the Temporal Lobe With Brainstem Involvement: A Case Report and Literature Review

Anaplastic ganglioglioma (AGG) is a rare and aggressive counterpart of the more benign and frequently encountered glioma. Herein, we present a 21-year-old female who presented with episodes of total amnesia and complex partial seizures, which led to the diagnosis of AGG localized to the medial temporal lobe. She subsequently underwent surgical cytoreduction of the tumor three times with adjuvant chemoradiotherapy. The extent of resection throughout the surgeries was hindered by the extension of the tumor to critical neurovascular structures; during the last surgery, invasion into the pons was noted, which posed a significant clinical challenge.

Pediatric primary anaplastic ganglioglioma with malignant neuronal component

Kaymak-Cihan M, Erdiş E, Bozkurt S, Ünver-Korğalı E. Pediatric primary anaplastic ganglioglioma with malignant neuronal component. Turk J Pediatr 2018; 60: 102-106. Gangliogliomas (GGs) represent approximately 0.4%-1.0% of all brain tumors. Anaplastic gangliogliomas (AGGs) form 5-10% of all GGs. They are a mixed neuronal-glial tumor of central nervous system and composed by two cell lines; neuronal (ganglionic) and glial cells. Anaplastic component of AGGs is usually glial cells. Malignant neuronal component is a rare condition. Here we report an 8-year-old male patient who was diagnosed with primary AGG with malignant neuronal component and was treated with surgery, adjuvant radiotherapy and chemotherapy.

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.

Vemurafenib in pediatric patients with BRAFV600E mutated high-grade gliomas

We present three pediatric patients with BRAFV600E mutant high-grade gliomas treated by vemurafenib on a nominative authorization level at our institution. One patient with anaplastic ganglioglioma experienced confirmed partial tumor response and significant clinical improvement and she is alive 20 months after start of treatment. A second patient with ganglioglioma responded transiently to re-introduction of vemurafenib after immunotherapy. Pharmacokinetic studies suggest that maximum concentration and exposure of vemurafenib at steady-state is dose-dependent and similar in children to that reported in adults. These cases suggest that BRAFV600 is an oncogenic driver in pediatric gliomas. Further exploration in clinical studies is ongoing.