Clinical and molecular characteristics of pediatric low-grade glioma complicated with ventriculo-peritoneal shunt related ascites

Introduction Ventriculo-peritoneal shunt (VPS) related ascites is a rare complication of pediatric low grade gliomas (pLGG). Physiopathology of this complication is not fully understood and there is paucity of data regarding the molecular profile of pLGG gliomas complicating with ascites and the optimal management of this unusual event. Methods International multi-institutional retrospective analysis of patients diagnosed with BRAF altered pLGG and ascites arising as a complication of VPS. Demographics, tumor characteristics, therapeutic approaches and outcomes were recorded. Results Nineteen patients were identified. Median age at diagnosis was 14 months (R: 2–144). Most patients (17; 89.4%) presented with lesions involving the optic pathway. Mean tumor standard volume was 34.8 cm 2 (R: 12.5–85.4). Pilocytic Astrocytoma was the most frequent histological diagnosis (14;7 3.7%). Eight (42.1%) tumors harbored BRAF V600-E mutation and seven (36.8%) KIAA1549 fusion. The onset of ascites was documented at a median time of 5 months following VPS insertion. Four (21%) patients were managed with paracentesis only, 7(36.8%) required both paracentesis and shunt diversion, 7(36.8%) required only a shunt diversion and 1 (5.2%) patient was managed conservatively. Chemotherapy regimen was changed in 10 patients following ascites. Eight patients received targeted therapy (4 dabrafenib/4 trametinib) and 5 were radiated. There were eleven survivors with a median OS of 69 months (R: 3–144). Conclusions Ascites is an early feature in the clinical course of young patients with midline BRAF altered pLGG, with high mortality rate observed in our cohort. The hypothesis of ascites as an adverse prognostic factor in pLGG warrants further prospective research.