弥漫性软脑膜胶质神经元肿瘤的临床、病理学特征

Clinicopathological characteristics of diffuse leptomeningeal glioneuronal tumor

目的探讨弥漫性软脑膜胶质神经元肿瘤(DLGNT)的临床、影像和组织学及分子遗传学特征;提高对DLGNT的诊断能力,并为临床处理提供经验。方法回顾分析2例DLGNT患儿的临床资料,总结其临床、影像、病理学特征和处理经过;并复习相关文献。结果本组2例患儿均为男性,年龄为9岁和7岁,均因“脑积水”入院。MRI检查均显示脑膜和脊膜多发性病灶,T2WI呈高信号囊状和结节状,增强扫描脑沟、脑裂及脑池多发性线状和环形异常强化影。组织病理学检查2例患儿均可见肿瘤侵犯软脑膜,少突胶质细胞样肿瘤细胞弥漫分布。例1患儿混有排列致密的小圆形、核深染的肿瘤细胞;例2患儿混有圆形、核仁明显、似节细胞样的肿瘤细胞,核分裂象不易见,未见坏死。免疫组化染色显示肿瘤细胞S-100、MAP-2、Olig-2均阳性,Syn部分(+),GFAP、NeuN不同程度阳性,IDH-1、H3K27M、BRAF V600E、NF、CD34和P53均阴性。例1患儿荧光原位杂交检测1p/19q显示1p染色体臂缺失。例1患儿行部分肿瘤切除后辅以替莫唑胺化疗和全中枢神经系统放疗,术后6个月死亡。例2患儿保守治疗2年10个月后发现肿瘤进展,行部分切除后对症处理,带瘤生存至少36个月。结论DLGNT好发于儿童,影像学表现为脑(脊)膜弥漫异常强化,其组织学形态和免疫表型具有胶质和神经元的双向分化,可伴1p染色体臂缺失。DLNGT的生物学行为仍不明确,有必要对患者进行长期随访。

Objective To investigate the histopathological,radiological and molecular genetic characteristics of diffuse leptomeningeal glioneuronal tumor(DLGNT),and improve understanding of the biological behavior of DLGNT.Methods The clinical data of 2 children patients with DLGNT were analyzed retrospectively.The clinicopathological characteristics were summarized and relevant literatures were reviewed.Results Two male children,aged 9 and 7,were admitted to hospital for“headaches and dizziness for half a month”and“headaches for 3 years,and intracranial mass lesion for 2 days”.MRI showed multiple cystic and nodular hyperintense masses on T2-weighted images with linear or ring-like enhancement located at the leptomeninges of cerebral sulci and spinal cord.Under the microscopy,the mass was composed of oligodendroglial-like tumor cells predominantly and widespreadly leptomeningeal growth in both cases.Another component was small round tumor cells with uniform round nuclei and scant cytoplasma in case 1 and ganglion-like round tomor cell with prominent nucleolus and abundant cytoplasm in case 2 and no mitotic figure or necrosis found in tumor.Immunohistochemically,oligodendroglial-like tumor cell was positive for S-100,MAP-2,Olig-2,and Syn in both cases.GFAP and NeuN were variablly positive.Neither tumor cells showed immunoreactive to IDH-1(R132H),H3K27M,BRAF V600E,NF,CD34and p53.There presented 1p deletion on FISH assay for 1p/19q co-deletion in case 1.The case 1 received adjuvant TMZ chemotherapy and radiotherapy after surgical partial excision of tumor.The patient was died at the sixth month of postoperatively following-up.And case 2 receied conservative treatment for 2 years and 10 months,then were performed surgical partial excision of tumor without radiotherapy and chemotherapy,the patient lived with the tumor for at least 36 months.Conclusions DLGNT is a rare glioneuronal neoplasm and preferentially occurs in children and young adults characterized by widespread leptomeningeal growth with diffusely leptomeningeal enhancement on MRI examination.The biological behavior of DLGNT is not clear completely,it is necessary to supervise the progression of tumor by long-term following-up.