LG-33: PEDIATRIC INFRATENTORIAL GANGLIOGLIOMA: RESULTS OF A SERIES OF 33 CHILDREN AND LITERATURE REVIEW

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 the results of 33 children treated for this tumor in our institution. RESULTS: We found 100 and 80 cases of brainstem and cerebellar pediatric ganglioglioma respectively in the literature. 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. Radiotherapy exposes the patient to 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.