Objective: To explore the clinical characteristics, imaging features, pathological manifestations and key points of diagnosis and treatment of polymorphous low-grade neuroepithelial tumor of the young (PLNTY), clarify the typical diagnostic criteria for this disease, and provide references for accurate clinical identification, standardized diagnosis and treatment. Methods: This study adopted a retrospective analysis approach, focusing on a 12-year-old male patient with PLNTY. Detailed clinical information (including medical history, past history, etc.), laboratory test results (blood routine, five coagulation indices, complete biochemical panel, etc.), imaging examination findings (CT, MRI) of the patient were collected. In addition, the surgical process and postoperative pathological examination results (routine pathology, immunohistochemistry, molecular pathology) were recorded. By integrating relevant literature, the diagnostic and therapeutic process of this patient was thoroughly reviewed to summarize the key diagnostic characteristics. Results: Polymorphous low-grade neuroepithelial tumor of the young is a rare, low-grade neuroepithelial tumor with indolent biological behavior. It predominantly occurs in children and adolescents and is often associated with a history of epileptic seizures. Key imaging features include:a single lesion with clear boundaries under the cortex; fine sand-like calcification with marginal cystic change; no obvious enhancement or peritumoral edema; and the “pepper-and-salt sign” and “transmantle sign”.