Cerebello-Pontine Angle Tumors in Children: An Update on Challenging Neoplasms

Introduction: Cerebellopontine angle (CPA) tumors are rare in children. As a result, knowledge on them is still limited, often concerning old series. The goal of this study is to provide an update on these challenging neoplasms by presenting a large series compared with those available in the literature and focusing on tumor characteristics, molecular pattern, extent of tumor removal, surgical complications, and outcome. Methods: All children with CPA tumors consecutively operated on between 2010 and 2020 (minimum follow-up: 5 years) and with complete follow-up data were considered. Retro-sigmoid approach was used for tumors arising from CPA (group A) while a midline sub-occipital was used for those extending into CPA (Group B). Intraoperative neuronavigation, neuro-monitoring, and ultrasounds were routinely utilized. Results: 48 children (54 tumors) were included (mean age at surgery: 6.9 years, 38% infants, M/F ratio 1.1). Hydrocephalus was present at diagnosis in 27% of cases. Gross total resection of the tumor was obtained in 59% of cases, and subtotal and partial resection in 24% and 17%, respectively. Complications occurred in 25% of cases. Group A was composed of 23 children: the most common tumor was schwannoma (43%) followed by ependymomas, medulloblastoma, AT/RT (13% each), and less common histotypes. Group B was composed of 25 children: ependymomas (60%), AT/RT (20%), medulloblastoma (12%), others (8%). All but one ependymomas belonged to PF-A molecular group, while medulloblastomas were equally divided between WNT and Sonic-Hedgehog. The overall survival rate after a mean 7.2-year follow-up is 71%. A total of 14 patients died because of tumor or disease progression. No statistical differences between the two groups were detected as far as demographic data, tumor growing pattern, extent of tumor removal, complication rate, and overall survival were concerned. Only the mean tumor diameter was significantly longer in group B (3.9 cm vs. 3.3 cm). Apart from some differences in the demography, the extent of tumor removal and complications, no relevant differences were noticed among the series analyzed. Conclusions: Pediatric CPA tumors are uncommon but not rare and present significant management challenges. Surgery is demanding. The long-term survival is poorly improved compared with the past and compared with other posterior fossa tumors, the prognosis is mainly related to the biological tumor characteristics and the adjuvant treatments rather than the surgical excision.