目的 分析儿童朗格汉斯细胞组织细胞增生症（Langerhans cell histiocytosis, LCH）的临床特点、疗效和预后。 方法 对72例初发LCH患儿进行回顾性分析。 结果 72例患儿中位年龄为5岁（范围：0~14岁），颅骨受累最常见（56例，78%）；BRAF-V600E突变与临床特征、疗效及预后无关（P>0.05）；5年总生存率91.6%±4.2%，5年无事件生存（event-free survival, EFS）率67.5%±5.8%。危险器官受累组6周化疗有效率和5年EFS率低于无危险器官受累组（P<0.05）；多系统受累组、血小板≥450×10⁹/L组5年总生存率分别低于单系统受累组和血小板<450×10⁹/L组（P<0.05）。其中危险器官受累是影响5年EFS的独立危险因素（P<0.05）。 结论 颅骨是儿童LCH最常累及部位。BRAF-V600E突变与其临床特征、疗效及预后无关。血小板增高、危险器官受累、多系统受累与预后不良相关，危险器官受累为5年EFS的独立危险因素。

Objective To study the clinical characteristics, efficacy, and prognosis of pediatric Langerhans cell histiocytosis (LCH). Methods A retrospective analysis was conducted on 72 children with newly diagnosed LCH. Results The median age of the 72 children was 5 years (range: 0-14 years), with skull involvement being the most common (56 cases, 77.8%). The BRAF-V600E mutation was not associated with clinical characteristics, efficacy, or prognosis (P>0.05). The 5-year overall survival rate was 91.6%±4.2%, and the 5-year event-free survival (EFS) rate was 67.5%±5.8%. The 6-week chemotherapy response rate and 5-year EFS rate were lower in the risk organ involvement group compared to the no risk organ involvement group (P<0.05). The five-year overall survival rates for the group with multi-system involvement and the group with platelet count ≥450×10⁹/L were respectively lower than those for the single-system involvement group and the group with platelet count <450×10⁹/L (P<0.05). Risk organ involvement is an independent risk factor for 5-year EFS (P<0.05). Conclusions Skull is the most commonly affected site in pediatric LCH. The BRAF-V600E mutation is not related to clinical characteristics, efficacy, or prognosis. Elevated platelet count, risk organ involvement, and multisystem involvement are associated with poor prognosis, with risk organ involvement being an independent risk factor for 5-year EFS.