Midline gliomas are tumors that occur in midline structures and can be circumscribed or diffuse. Classical midline structures include the thalamus, brainstem, and spinal cord. Other midline structures include the corpus callosum, basal ganglia, ventricles, paraventricular structures, and cerebellum. Diffuse midline glioma (DMG) is a diffuse glioma that occurs in the classical midline structures, characterized by a specific genetic alteration, and associated with grim outcome. This study was conducted at King Hussein Cancer Center and reviewed the medical records of 104 patients with circumscribed and diffuse gliomas involving midline structures that underwent biopsy between 2005 and 2022. We included a final cohort of 104 patients characterized by a median age of 23 years and a male-to-female ratio of 1.59-to-1. Diffuse high-grade glioma (DHGG) was the most common pathological variant (41.4%), followed by DMG (28.9%). GFAP was positive in most cases (71.2%). Common positive mutations/alterations detected by surrogate immunostains included H3 K27me3 (28.9%), p53 (25.0%), and H3 K27M (20.2%). Age group, type of treatment, and immunohistochemistry were significantly associated with both the location of the tumor and tumor variant (all;p< 0.05). DMGs were predominantly found in the thalamus, whereas circumscribed gliomas were most commonly observed in the spinal cord. None of the diffuse gliomas outside the classical location, or circumscribed gliomas harbored the defining DMG mutations. The median overall survival (OS) for the entire cohort was 10.6 months. Only the tumor variant (i.e., circumscribed gliomas) and radiotherapy were independent prognosticators on multivariate analysis.
中线胶质瘤是发生于中线结构的肿瘤，可分为局限性和弥漫性两类。经典中线结构包括丘脑、脑干和脊髓。其他中线结构涵盖胼胝体、基底节、脑室、脑室旁结构及小脑。弥漫性中线胶质瘤（DMG）特指发生于经典中线结构的弥漫性胶质瘤，具有特定基因改变特征，且预后不良。本研究在侯赛因国王癌症中心开展，回顾分析了2005年至2022年间接受活检的104例累及中线结构的局限性与弥漫性胶质瘤患者病历。最终纳入的104例患者中位年龄为23岁，男女比例为1.59:1。弥漫性高级别胶质瘤（DHGG）是最常见的病理亚型（41.4%），其次为DMG（28.9%）。多数病例GFAP呈阳性表达（71.2%）。通过替代免疫组化检测发现的常见阳性突变/改变包括H3 K27me3（28.9%）、p53（25.0%）和H3 K27M（20.2%）。年龄分组、治疗方式及免疫组化特征均与肿瘤部位及亚型显著相关（均p<0.05）。DMG主要发生于丘脑，而局限性胶质瘤最常见于脊髓。在经典中线结构以外发生的弥漫性胶质瘤及所有局限性胶质瘤均未检测到DMG特征性突变。全队列中位总生存期（OS）为10.6个月。多变量分析显示，仅肿瘤亚型（即局限性胶质瘤）与放疗是独立的预后影响因素。
Midline Gliomas: A Retrospective Study from a Cancer Center in the Middle East
肿瘤(癌症)患者之家