Diffuse Leptomeningeal Glioneuronal Tumor Presented with Language Developmental Delay.

: Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a new central nervous system tumor defined by the WHO in 2016 characterized mainly by hydrocephalus, headache, and epilepsy. We reported the case of a patient diagnosed with DLGNT who presented with language developmental delay and positive but subtle changes in imaging two years before the emergence of typical clinical symptoms. Few studies were conducted on early tumor symptoms due to the limited number of cases. We hypothesized that with the existence of pre-tumor symptoms, language developmental delay may be related to tumor.