Department of Pathology, All India Institute of Medical Sciences, Rajkot, Gujarat, India.
J Med Life. 2024 Jul;17(7):665-670. doi: 10.25122/jml-2023-0515.
The World Health Organization (WHO) Central Nervous System (CNS) Tumors Classification 5 edition (2021) integrates both molecular and histopathological criteria for diagnosing glial tumors. This updated classification highlights significant differences between pediatric and adult gliomas in terms of molecular characteristics and prognostic implications. The 5 edition comprises a new category of pediatric-type diffuse low-grade glioma (PDLGG) and pediatric-type diffuse high-grade glioma (PDHGG), classified mainly based on genetic alterations and histopathological features. We reviewed the microscopy, diagnostic molecular pathology, and prognosis of various tumors under the categories PDLGG and PDHGG. The review also addresses the need for clarification concerning overlapping diagnostic features. PDLGG are characterized by diffuse growth, low-grade morphology, and MYB/MYBL1(MYB Proto-Oncogene Like 1) gene fusion or mitogen-activated protein kinase (MAPK) pathway alterations. In contrast, PDHGG is described by diffuse growth, high-grade morphology, and increased mitosis and often shows alterations of histone gene resulting in epigenetic alterations, which contrasts with common isocitrate dehydrogenase (IDH) mutation and epidermal growth factor receptor (EGFR) amplification seen in adult-type high-grade glioma.
世界卫生组织（WHO）中枢神经系统（CNS）肿瘤分类第五版（2021 年）整合了用于诊断神经胶质瘤的分子和组织病理学标准。这一更新的分类突出了儿童和成人神经胶质瘤在分子特征和预后意义方面的显著差异。第五版包括一种新的儿童型弥漫性低级别胶质瘤（PDLGG）和儿童型弥漫性高级别胶质瘤（PDHGG）类别，主要基于遗传改变和组织病理学特征进行分类。我们回顾了 PDLGG 和 PDHGG 类别下各种肿瘤的显微镜、诊断分子病理学和预后。该综述还涉及对重叠诊断特征进行澄清的必要性。PDLGG 的特征为弥漫性生长、低级别形态以及 MYB/MYBL1（MYB 原癌基因样 1）基因融合或丝裂原活化蛋白激酶（MAPK）通路改变。相比之下，PDHGG 以弥漫性生长、高级别形态、增加的有丝分裂和通常表现为组蛋白基因改变导致表观遗传改变为特征，与成人型高级别胶质瘤中常见的异柠檬酸脱氢酶（IDH）突变和表皮生长因子受体（EGFR）扩增形成对比。
