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

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.

Glioneuronal Tumor With Features of Ganglioglioma and Neurocytoma Arising in the Fourth Ventricle: A Report of 2 Unusual Cases and a Review of Infratentorial Gangliogliomas

Infratentorial glioneuronal neoplasms are overall quite rare and are more commonly low-grade with surgical excision usually being curative. Multiple distinct histologic entities have been described including rosette-forming glioneuronal tumor, papillary glioneuronal tumor, neurocytoma, dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos disease), cerebellar liponeurocytoma, and ganglioglioma. While each of these entities has distinct findings, in some instances a tumor may demonstrate overlapping histologic features with mixed components. Herein, we report 2 unusual adult cases of a fourth ventricular glioneuronal tumor with features of ganglioglioma and neurocytoma, with one coming from a surgical resection and one found incidentally at autopsy. To the best of our knowledge, this specific histologic combination has not previously been described. As such, the clinical significance is unknown although in both cases the neoplasms were circumscribed and appeared to be low grade. The presence of the gangliogliomatous component was of particular interest since these are extremely rare occurrences in the fourth ventricle and we provide a comprehensive review of infratentorial gangliogliomas.

Bilateral internal auditory canal gangliogliomas mimicking neurofibromatosis Type II

Background:

Gangliogliomas are rare low grade, typically well-differentiated, tumors that are composed of mature ganglion cells and neoplastic glial cells. These tumors can appear at virtually any location along the neuroaxis but classically occur in the temporal lobe of young patients. In a small number of cases, gangliogliomas have presented as masses in the brainstem or involving cranial nerves. With the exception of vestibular schwannomas, bilateral tumors in the region of the internal auditory canal (IAC) or cerebellopontine angle (CPA) are exceedingly rare.

Case Description:

We report a case of a 58-year-old male who presented with hearing loss, tinnitus, and vertigo. Initial magnetic resonance imaging revealed bilateral nonenhancing IAC/CPA tumors. Based on this finding, a presumptive diagnosis of neurofibromatosis Type II was made, which was initially managed conservatively with close observation. He returned for follow-up with worsening vertigo and tinnitus, thus prompting the decision to proceed with surgical resection of the symptomatic mass. Intriguingly, pathological study demonstrated a WHO Grade I ganglioglioma.

Description:

We report a case of a 58-year-old male who presented with hearing loss, tinnitus, and vertigo. Initial magnetic resonance imaging revealed bilateral nonenhancing IAC/CPA tumors. Based on this finding, a presumptive diagnosis of neurofibromatosis Type II was made, which was initially managed conservatively with close observation. He returned for follow-up with worsening vertigo and tinnitus, thus prompting the decision to proceed with surgical resection of the symptomatic mass. Intriguingly, pathological study demonstrated a WHO Grade I ganglioglioma.

Conclusion:

This is the first reported case of bilateral IAC/CPA gangliogliomas. When evaluating bilateral IAC/CPA lesions with unusual imaging characteristics, ganglioglioma should be included in the differential diagnosis.

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.