摘要Diffuse leptomeningeal glioneuronal tumor (DLGNT) in adolescent female is rare and easy to be misdiagnosed due to its nonspecificity. This arti-cle described the characteristics of an adolescent female DLGNT patient with no history of tumor whose first symptoms are headache and vision loss, and analyzed the causes why DLGNT is easy to be misdiagnosed as cryptococcal meningitis. Treatment remedies: the ado-lescent female presented with progressive exacerbations of headache, vomiting and vision loss after general treat-ment. Dynamic monitoring of routine biochemical chang-es in cerebrospinal fluid (CSF) found abnormal high CSF pressure and protein, repeated examination of antibodies and acid-fast bacilli were negative, and high-throughput pathogen gene examination excluded viral meningitis, tu-berculous meningitis and other diseases. To save the optic nerve, the Ommaya capsule was implanted to reduce the intracranial pressure. After diagnostic antifungal treat-ment, the patient's condition did not improve. To identify the etiology, extensive meningeal enhancement was even-tually detected by enhanced magnetic resonance imaging (MRI), and highly atypical tumor cells were identified by repeated examination of fresh CSF cytology. Post treat-ment evaluating: for DLGNT, consult oncology. Menin-geal biopsy and PET-CT (positron emission tomography-computed tomography) examination were recommended, and intrathecal chemotherapy and whole-brain radiother-apy were performed according to the examination results. But the patient's family refused to have a meningeal bi-opsy and asked to be released from the hospital. Conclu-sions: the adolescent female without a history of tumor can not rule out the disease, and cryptococcal meningitis also has meningeal enhancement. The gold standard for the diagnosis of DLGNT is to find cancer cells. There is no effective cure for DLGNT, the timely placement of Ommaya sac can significantly improve the quality of the patient's life, and the active adoption of targeted therapy is expected to extend the patient's survival.