肥胖细胞型星形细胞瘤的影像学表现与病理研究

Gemistocytic astrocytoma:correlation of CT and MRI findings and pathology

目的：探讨肥胖细胞型星形细胞瘤（gemistocytic astrocytoma ，GemA）的影像学及临床病理特征。方法回顾性分析经手术及病理证实的10例 GemA 的临床及影像资料。2例行 CT 平扫，8例行 MR 平扫及增强扫描，结合相关文献分析其影像特征。结果共10例患者，男7例，女3例，年龄10～64岁。全部位于幕上，发生在额叶7例；9例单发，1例多发；8例表现为边界不清、弥漫性生长；6例累及多个脑叶，其中5例通过胼胝体侵犯对侧大脑半球；6例肿瘤实性成分内见多发、大小不等的囊变区；1例还表现为大囊小结节型，实性结节位于脑膜面侧。 MRI 肿瘤的实性成分在 T1 WI 呈等或稍低信号，在 T2 WI 呈稍高或高信号，在 DWI 呈稍高或高信号，ADC 图呈低或稍低信号；增强后2例无明显强化；6例肿瘤的实性成分呈明显强化，强化大多不均匀。 CT 表现肿瘤呈低密度，伴有轻度水肿，1例瘤内伴有点状钙化。肿瘤最大径约3．0～8．1cm ；瘤周轻度水肿9例，中度水肿1例。结论 GemA 的 MRI 表现具备一定的特点，了解这些特征，有助于对该病的术前诊断及鉴别诊断。

Objective To analyze the imaging features and pathologic characteristic of gemistocytic astrocytoma .Methods The MRI imaging of 10 patients with GemA were reviewed retrospectively ,and imaging features and clinical data were an‐alyzed .2 cases underwent CT ,8 cases underwent both plain and enhanced MRI scanning .Pertinent literatures were re‐viewed ,and the image features were analyzed .Results Among the 10 patients ,7 were male and 3 were female with age ranged from 10 to 64 years .All the tumors located at supratentorial site .7 cases was located in the lobus frontalis .Single tumor was found in 9 patients ,multiple tumor in 1 patients 8 patients had no clear mass and diffuse infiltrative growth .6 cases involved in several lobes and 5 cases invaded the opposite tissues through corpus callosum .6 patients showed multi‐ple and various sizes cystic lesions in solid parts .Cystic‐solid tumor large mural nodule was presented （1 case） .The solid nodules were located nearby the meninx of tumor .The solid portions of the tumor demonstrated isointensity or slightly hy‐pointense on T1 WI ,isointensity or slightly hyperintense on T2 WI and hyperintense or slightly hyperintense on DWI ,isoin‐tensity or hypointense on ADC map .The solid masses were marked enhancement after Gd‐DTPA injection ,the enhance‐ment of the components was inhomogeneous .Low density was shown on CT with mild edema .The maximum diameter of tumors was 3.0 ~ 8 .1 cm .Peritumoral edema was found in 10 cases with mild in 9 eases ,moderate edema in 1 case respec‐tively .Conclusion GemA has certain MRI features and understanding these features will help its diagnosis and differential diagnosis .