Lymphoepithelioma-like carcinoma (LELC) in children is a rare epithelial malignant tumor. Regarding pediatric lymphoepithelioma-like carcinoma (pLELC), its clinicopathological features, prognosis, and molecular characteristics remain unknown. In preclinical studies, this study aims to explore the safety and efficacy of the PD-1 monoclonal antibody pucotenlimab combined with the chemotherapy regimen of gemcitabine and cisplatin as the first-line treatment for lymphoepithelioma-like carcinoma in children and adolescents.