Abstract
Diffuse leptomeningeal glioneuronal tumor has a high degree of malignancy and high mortality. The purpose of this paper is to describe the characteristics of atypical diffuse leptomeningeal glioneuronal tumor and analyze the causes of misdiagnosis as viral meningoencephalitis. An adolescent female patient presented with headache, nausea, vomiting, sharp vision loss and cognitive dysfunction. After poor therapeutic effect of standard antiviral treatment, further inspection found that malignant cells were detected by cerebrospinal fluid (CSF) cytology; and enhanced magnetic resonance imaging (MRI) showed extensive enhancement of the leptomeningeal. In conclusions, when patient with unexplained high intracranial pressure, it is necessary to be alert to the diagnosis of diffuse leptomeningeal glioneuronal tumor. Multiple examinations of fresh CSF are helpful to increase the positive detection rate of tumor cells. Early diagnosis and active treatment are conducive to improving survival rate.