Clinical and MRI findings in patients with pediatric optic pathway glioma presenting with initial leptomeningeal dissemination

Aims: Although leptomeningeal dissemination (LMD) is a hallmark of malignant brain tumors, optic pathway glioma (OPG) of various grades can initially present with LMD, which is thenceforth interpreted as an aggressive tumor. In this study, we aimed to evaluate the clinical and imaging findings of pediatric OPG (POPG) patients who presented with initial LMD to ensure a prompt diagnosis and better outcomes. Materials and Methods: Between 2000 and 2022, 35 pediatric patients with pathologically proven OPG who presented with and without LMD at our institute were retrospectively reviewed. We compared the demographic and histopathology characteristics, magnetic resonance imaging features, and clinical outcomes of the initial LMD group and the non-LMD group. Results: Compared with those in the non-LMD group (n = 27), POPGs in the LMD group (n = 8) were more symmetrically midline-positioned (75% versus 22.2%, P =.006) and had more ill-defined tumor borders (25% versus 0%, p =.007), and patients were more likely to develop hydrocephalus (100% versus 63%, P =.042). There was no significant difference regarding the histopathology (P =.686) and outcome of tumor recurrence/progression (P =.341). However, the mortality rate was higher in the LMD group than in the non-LMD group (62.5% versus 18.5%, P =.016). Conclusions: Features of a more symmetrical midline-positioned POPG with indistinct tumor borders and hydrocephalus are risk factors for initial LMD regardless of histopathology. Compared with those without initial LMD, patients with POPG with initial LMD had poorer outcomes, which may suggest the need for a more aggressive treatment protocol.