Pediatric pleomorphic xanthoastrocytomas: A multicenter neuroradiological and clinical correlation study

Background and purpose: Pleomorphic Xanthoastrocytomas (PXAs) are rare pediatric brain tumors accounting for approximately 1% of primary brain neoplasms in children and young adults. Despite recent imaging and molecular advances, gaps remain in our understanding of their diverse imaging characteristics and clinical outcomes. This study provides a large international, multi-institutional analysis of pediatric PXAs focusing on neuroimaging and clinical outcomes.Materials and methods: We conducted a retrospective international multi-center study including 63 pediatric patients with histologically confirmed PXAs. Neuroimaging data were reviewed, and molecular analyses were recorded with emphasis on BRAF V600E mutations and CDKN2A/B deletions. Treatment modalities and clinical outcomes, including progression-free and overall survival, were analyzed using statistical survival models.Results: 73.3% of tumors were CNS WHO grade 2 and 26.7% were CNS WHO grade 3. The median age at diagnosis was 10.7 (IQR 6.9) years. CNS WHO grade 3 tumors were significantly larger at diagnosis, with a median volume of 87,920 mm³ compared with 14,925 mm³ for grade 2 tumors (p = 0.03). BRAF V600E mutations were identified in 78% of cases and CDKN2A/B deletions in 93.5%. On MRI, PXAs typically appeared well-defined, with cortical and leptomeningeal contact (86.0% and 56.4%, respectively), frequent cysts (59.6%), and intermediate diffusivity (mean ADC 1005 × 10-6 mm2/s). CT imaging showed most tumors were isointense to gray matter (52.0%), with hydrocephalus more common in grade 3 tumors (71.4% vs. 26.3%, p = 0.07). Gross total resection was achieved in 73.7% of cases and was associated with improved progression-free survival, independent of age at diagnosis and tumor grade (HR = 0.39; 95% CI, 0.16-0.96; p = 0.041). Larger tumor volume correlated with poorer survival outcomes (HR = 3.47; 95% CI, 0.83-14.4; p = 0.087), also independent of tumor grade and age at diagnosis. Tumor recurrence occurred in 44.8% of patients at three years. The estimated three-year overall survival rate was 94.7%.Conclusions: Pediatric PXAs exhibit distinct neuroimaging and molecular features correlating with prognosis. Integrated evaluation of radiological and clinical features is critical to improve risk stratification and guide personalized therapeutic strategies in this rare tumor population.