BRAVF-V600E突变型实性多形性黄色星形细胞瘤的MRI分析

MRI characteristics of solid pleomorphic xanthoastrocytoma with BRAVF-V600E mutations

目的:探讨BRAVF-V600E突变型实性多形性黄色星形细胞瘤(Pleomorphic xanthoastrocytoma,PXA)的MRI表现。方法:回顾性分析8例经病理证实为PXA、分子检测为BRAVF-600突变及MRI表现为实性肿块患者的临床及MRI资料,总结其MRI表现。结果:8例均为女性患者,平均年龄(41±14.2)岁。8例均为幕上单发病灶,额叶4例,左侧顶叶2例,左侧枕叶1例,右侧枕叶1例,呈类圆形、椭圆形或分叶状实性肿块,2例病灶以宽基底与大脑镰相连,5例病灶边缘见小囊变。瘤体T_(1)WI呈等/低信号,T_(2)WI及T_(2)FLAIR以稍高/高信号为主,DWI呈高/稍高信号,ADC图呈稍低信号;增强扫描1例局部斑片状强化,余7例呈明显均匀或不均匀强化,其中6例强化瘤体白质侧部分边界模糊,边缘见条状或尖角样明显或磨玻璃样强化区;5例累及邻近脑膜;7例瘤周重度水肿。3例1 H-MRS检查示病灶NAA峰降低,Cho峰升高,2例出现Lac峰。结论:BRAVF-V600E突变型实性PXA的MRI表现有一定特征性,中年患者脑皮层或皮层下实性肿块伴瘤周重度水肿,增强明显强化,注意识别强化瘤体周围的磨玻璃样强化区有助于其术前诊断及鉴别诊断。

Objective:To investigate the MRI features of solid pleomorphic xanthoastrocytoma(PXA)with BRAVF-V600E mutations.Methods:The clinical and MRI data of eight patients confirmed PXA,BRAVF-V600E mutations and solid masses were analyzed retrospectively.The MRI findings were summarized.Result:Eight cases were female patients with a mean age of(41±14.2)years.Eight cases were single supratentorial lesions,four frontal lobes,two left parietal lobes,one left occipital lobe,and one right occipital lobe.The solid mass was round,oval,or lobulated.Two lesions connected to the brain with wide bases.Five lesions showed small cystic changes at the edge.The mass showed isointensity/hypointensity on T_(1)WI,slightly hy-perintensity/hyperintensity on T_(2)WI and T_(2)-FLAIR,heterogeneous hyperintensity/slightly hyperintensity on DWI,and slightly hy-pointensity on ADC maps.On contrast-enhanced scans,one patient had local patchy enhancement,and the remaining seven patients had significant homogeneous or heterogeneous enhancement,of which six patients had blurred borders on the white matter side with strip or sharp corner-like significant or ground-glass enhancement areas at the edges.Five patients showed adjacent meningeal thickening and enhancement.Seven patients had severe peritumoral edema.There were three lesions showed decreased NAA peak and increased Cho peak,and two lesions showed Lac peak in 1 H-MRS.Conclusion:The solid PXA with BRAVF-V600E mutations have some characteristics in MRI.Middle-aged patients have cortical or subcortical solid masses with severe peritumoral edema and significant enhancement.Attention should be paid to identify ground-glass enhance-ment areas around the enhanced tumor,which is helpful for its preoperative diagnosis and differential diagnosis.