Objective: To summarize the clinical, pathological and molecular characteristics of various types of pediatric glioma, and to explore the differences in the morphology and clinical significance among various types of pediatric glioma. Methods: Based on the fifth edition of the World Health Organization classification of central nervous system tumors, this study classified or reclassified 111 pediatric gliomas that were diagnosed at Guangzhou Medical University Affiliated Women and Children's Medical Center from January 2020 to June 2023. The clinical manifestations, imaging findings, histopathology, and molecular characteristics of these tumors were analyzed. Relevant literature was also reviewed. Results: The 111 patients with pediatric glioma included 56 males and 55 females, with the age ranging from 10 days to 13 years (average age, 5.5 years). Clinically, manifestations presented from 5 days to 8 years before the diagnosis, including epilepsy in 16 cases, increased intracranial pressure in 48 cases and neurological impairment in 66 cases. MRI examinations revealed tumor locations as supratentorial in 43 cases, infratentorial in 65 cases, and spinal cord in 3 cases. There were 73 cases presented with a solid mass and 38 cases with cystic-solid lesions. The largest tumor diameter ranged from 1.4 to 10.6 cm. Among the 111 pediatric gliomas, there were 6 cases of pediatric diffuse low-grade glioma (pDLGG), 63 cases of circumscribed astrocytoma glioma (CAG), and 42 cases of pediatric diffuse high-grade glioma (pDHGG). Patients with pDLGG and CAG were younger than those with pDHGG. The incidence of pDLGG and CAG was significantly lower in the midline of the infratentorial region compared to that of pDHGG. They were more likely to be completely resected surgically. The pDLGG and CAG group included 4 cases of pleomorphic xanthoastrocytoma, showing histological features of high-grade gliomas. Among the high-grade gliomas, 13 cases were diffuse midline gliomas and also showed histological features of low-grade glioma. Immunohistochemical studies of H3K27M, H3K27ME3, p53, ATRX, BRAF V600E, and Ki-67 showed significant differences between the pDLGG and CAG group versus the pDHGG group (P<0.01). Molecular testing revealed that common molecular variations in the pDLGG and CAG group were KIAA1549-BRAF fusion and BRAF V600E mutation, while the pDHGG group frequently exhibited mutations in HIST1H3B and H3F3A genes, 1q amplification, and TP53 gene mutations. With integrated molecular testing, 2 pathological diagnoses were revised, and the pathological subtypes of 35.3% (12/34) of the pediatric gliomas that could not be reliably classified by histology were successfully classified. Conclusions: There are significant differences in clinical manifestations, pathological characteristics, molecular variations, and prognosis between the pDLGG, CAG and pDHGG groups. The integrated diagnosis combining histology and molecular features is of great importance for the accurate diagnosis and treatment of pediatric gliomas.
目的： 探讨各类型儿童胶质瘤的临床病理及分子特征之间的差异及其临床意义，丰富儿童胶质瘤的整合诊断经验。 方法： 基于第5版WHO中枢神经系统肿瘤分类，对2020年1月至2023年6月广州医科大学附属妇女儿童医疗中心诊断的儿童胶质瘤111例进行整合/分层诊断。收集111例患者的临床表现、影像学、组织病理学及分子检测结果进行分析，并复习相关文献。 结果： 111例儿童胶质瘤患者年龄10 d至13岁，平均年龄5.5岁。男56例，女55例。临床表现，出现症状持续时间5 d~8年，癫痫16例，颅内压增高48例，神经功能损伤66例。磁共振成像（MRI）检查示肿物位于幕上43例，幕下65例，脊髓3例；实性占位性病变73例，囊实性38例，最大径1.4~10.6 cm。病理类型上，111例胶质瘤中，儿童型弥漫性低级别胶质瘤（pDLGG）6例，局限性星形细胞胶质瘤（CAG）63例，儿童型弥漫性高级别胶质瘤（pDHGG）42例。pDLGG和CAG的患者年龄低于pDHGG。pDLGG及CAG的发病率在幕下中线部位显著低于pDHGG，并且更易通过手术完全切除。在pDLGG和CAG中，有4例多形性黄色瘤样星形细胞瘤，呈现高级别胶质瘤的组织学特征；而在高级别胶质瘤中，有13例弥漫中线胶质瘤，呈现低级别胶质瘤的组织学特征。免疫组织化学指标（H3K27M、H3K27ME3、p53、ATRX、BRAF V600E和Ki-67等）在pDLGG及CAG组与pDHGG组之间差异有统计学意义（P<0.01）。分子检测结果表明，pDLGG和CAG常见的分子变异为KIAA1549-BRAF融合和BRAF V600E突变，而pDHGG常见的分子变异为HIST1H3B及H3F3A基因突变、染色体1q扩增及TP53基因突变。通过结合分子检测结果，修正了2例病理诊断，并明确了35.3%（12/34）组织学无法确诊的儿童型胶质瘤的病理分型。 结论： pDLGG及CAG与pDHGG在临床表现、病理特征、分子变异及预后方面存在显著差异。结合组织形态和分子特征的整合诊断对于精准诊疗儿童胶质瘤具有重要意义。.