双语病例——弥漫性中线胶质瘤
朗读老师：章维 昆明医科大学第二附属医院
History and MR images
病史与MR影像
History: A 33-year-old man presents to the emergency department with a chronic headache that acutely worsened. The patient reports that he had previously received a diagnosis of isolated neurosarcoidosis.
病史：一名33岁男性因慢性头痛急性恶化就诊于急诊科。患者自述以前曾被诊断为孤立性神经结节病。
A contrast-enhanced MRI scan of the head was performed, and images are shown below, including axial T2-weighted, diffusion-weighted, gradient-recalled echo, T1-weighted pre- and postcontrast, and sagittal T1-weighted images.
对病人头部进行了增强MRI扫描，图像如下所示，包括轴位T2加权、扩散加权、梯度回波、T1加权前后对比和矢状T1加权图像。
Additional images
附加图像
Based on the head MRI findings, an MRI scan of the spine was performed. Example images from the MRI of the cervical spine, including T1-weighted pre- and postcontrast and short tau inversion-recovery (STIR) images, are shown below.
根据头部MRI检查结果，对脊柱进行了MRI扫描。从颈椎MRI的病例，包括T1加权前后对比和反转恢复(STIR)图像，如下所示。
Findings and diagnosis
发现和诊断
Findings
发现
MRI demonstrates an expansile, nonenhancing T2-hyperintense mass in the pons and medulla without associated susceptibility or restricted diffusion.
MRI显示脑桥白质中存在膨胀性的、无强化的T2高信号肿块，没有相关的磁敏感信号或扩散受限。
Diffuse leptomeningeal enhancement is seen in the brain and spine.
在大脑和脊柱中可见弥漫性软脑膜增强。
Differential diagnoses
鉴别诊断
Brainstem signal abnormality:
脑干信号异常：
Ischemia
脑梗
Rhombencephalitis
菱脑炎
Demyelinating disease
脱髓鞘性疾病
Osmotic demyelination
渗透性脱髓鞘
Glioma
胶质瘤
Leptomeningeal enhancement:
软脑膜强化：
Infectious meningitis, particularly tuberculous or fungal
传染病性脑膜炎，特别是结核性脑膜炎或真菌性脑膜炎
Neurosarcoidosis
神经结节病
Leptomeningeal spread of tumor, including metastatic disease
肿瘤的软脑膜扩散，包括转移性疾病
Glioma
胶质瘤
Lymphoma/leukemia
淋巴瘤/白血病
Diagnosis: Diffuse midline glioma, H3 K27M-mutant
诊断：弥漫性中线胶质瘤H3K27M突变型
Discussion
讨论
Diffuse midline glioma
弥漫性中线胶质瘤
Pathophysiology
病理生理学
Diffuse brainstem gliomas, a group of tumors no longer recognized in the 2016 WHO classification of CNS tumors, previously included the majority of brainstem gliomas. However, recent advances in the understanding of CNS tumor genotypes have revealed that many of these tumors share the H3 K27M mutation in a histone gene and demonstrate diffuse growth within midline structures, such as the thalamus, brainstem, cerebellum, or spinal cord. Thus, the 2016 WHO classification recognizes these tumors as diffuse midline gliomas, H3 K27M-mutant.
弥漫性脑干胶质瘤是一组在2016年WHO中枢神经系统肿瘤分类中不再被承认的肿瘤，以前包括了大多数脑干胶质瘤。然而，最新对中枢神经系统肿瘤基因型理解的研究进展表明，许多这些肿瘤在组蛋白基因中都有H3K27M突变，并在中线结构，如丘脑、脑干、小脑或脊髓中显示出弥漫性生长。因此，2016年WHO分类认为这类肿瘤为弥漫性中线胶质瘤，H3K27M突变。
Epidemiology
流行病学
Diffuse midline gliomas, H3 K27M-mutant occur predominantly in children. Nevertheless, they can also occur in adults. In children, the presence of the H3 K27M mutation portends a poor prognosis, with a two-year survival of less than 10%. In adults, tumors with the H3 K27M mutation have a similar or better prognosis compared with wild-type tumors, although median survival is still less than two years.
弥漫性中线胶质瘤，H3K27M突变主要发生在儿童.然而，它们也可能发生在成年人身上。在儿童中，H3K27M突变的存在预示着预后不良，两年生存率不到10%。在成人中，与野生型肿瘤相比，H3K27M突变的肿瘤具有相似或更好的预后，尽管中位生存期仍小于两年。
Clinical presentation
临床表现
Presentation is dependent on tumor location and may include evidence of elevated intracranial pressure, such as headache, nausea, and emesis; cranial nerve dysfunction, such as facial and ocular nerve palsies; and cerebellar signs, such as ataxia.
表现取决于肿瘤的位置，可能包括颅内压升高的征象，如头痛、恶心和呕吐；颅神经功能障碍，如面神经和眼神经麻痹；小脑体征如共济失调。
Imaging features
影像特征
Diffuse midline gliomas have various appearances on MRI and demonstrate variable degrees of necrosis, enhancement, infiltrative T2/fluid-attenuated inversion-recovery (FLAIR) signal, irregular borders, and expansile mass effect. Most commonly, the tumor will be T2-hyperintense with little to no contrast enhancement and no restricted diffusion.
弥漫性中线胶质瘤MRI表现多样，表现为不同程度的坏死、强化、浸润性的T2-FLAIR信号、边界不规则和肿瘤膨胀性生长。最常见的是，肿瘤表变现为T2高信号，几乎没有强化和弥散受限。
Patients with diffuse midline gliomas may uncommonly present with leptomeningeal dissemination. This dissemination may be limited in extent with scattered foci or diffuse, as in this case.
弥漫性中线胶质瘤的患者可能通常表现为软脑膜播散。这种播散可能受到限制、散在或弥漫，如本例。
Treatment
治疗
Because of the locations of diffuse midline gliomas, there is often limited opportunity to resect them. In addition, the general lack of enhancement is a predictor of poor response to chemotherapy. Radiotherapy is the standard treatment.
Future directions for treatment include targeted therapies based on the tumor’s characteristic protein-expression profile and convection-enhanced delivery of chemotherapy, a technique in which chemotherapy is delivered through infusion catheters directly into the brain parenchyma, bypassing the limitation of conventional chemotherapy in the treatment of diffuse midline glioma.
由于弥漫性中线胶质瘤的位置特点，切除的机会往往有限。此外，普遍缺乏强化是化疗不良反应的一个预测因素。放射治疗是标准的治疗方法。未来的治疗方向包括基于肿瘤特征蛋白表达谱的靶向治疗和对流增强化疗，这种技术通过灌注导管直接进入脑实质，绕过常规化疗在治疗弥漫性中线胶质瘤中的局限性。