基本情况:患者,女性,66岁,急性脑血管病入院。 MRI图像: Diagnosis Choroid plexus xanthogranuloma 脉络丛黄色肉芽肿
【图像所见】
双侧侧脑室三角区各见一囊状T1WI稍低信号(图2)、T2WI及FLAIR高信号(图1、图3),DWI( b=1000s/mm²)呈高信号,ADC呈稍低信号,边界清晰,双侧基本对称分布。 【诊断意见】 双侧侧脑室三角区脉络丛黄色肉芽肿。
脉络丛黄色肉芽肿 脉络丛黄色肉芽肿是发生于脉络丛的特发性良性退行性改变,常位于双侧侧脑室三角区,患者常无症状。 【病理】 病理机制尚不明确。组织学上主要由黄瘤细胞、脂质细胞构成。 【MRI表现】 平扫:黄色肉芽肿的MR表现为双侧侧脑室三角区形态规则的结节,T1WI稍低信号,T2WI、FLAIR呈等或稍高信号。由于ⅩG病灶内含有较丰富的胆固醇结晶,扩散受限,于DWI上表现为高信号,ADC值稍减低。 增强:增强后强化特点,可有多种强化特点: ①无强化; ②病灶中心不强化,边缘可见强化,一般认为是黄色肉芽肿周围包绕的脉络丛强化所致;
③结节状强化; ④实性部分强化; Key Points
Choroid plexus xanthogranulomas are cysts that usually range in size from 2 mm to 8 mm and rarely are larger than 2 cm. 脉络丛黄色肉芽肿是大小约2-8mm的囊性病变,很少超过2cm。 They are usually bilateral and multiple. 通常为多发、双侧对称性发病。 On CT, the cysts are isodense or slightly hyperdense to cerebral spinal fluid. Irregular and peripheral calcium in these cysts is common in adults. CT上,囊肿与脑脊液相比呈等或略高密度,成年患者的病灶周边可见钙化。
On MRI, 60% to 80% show restricted diffusion; usually iso- or hypointense but can be hyperintense on FLAIR; and enhancement (ring, nodular, solid) varies from none to strong. MRI上,约60%-80%的病灶弥散受限、DWI呈高信号。通常病灶呈等或稍低信号,但FLAIR可呈高信号。增强扫描病灶可无强化,也可以呈环形强化、结节状强化、实性部分强化等多种强化方式。
EtiologyIn adults: Lipid from desquamating, degenerating choroid epithelium accumulates in choroid plexus. Lipid provokes xanthomatous response. 成人:脉络膜上皮退变、碎屑中的脂质成分积聚在脉络丛,进一步诱发脉络丛肉芽肿反应。 In fetuses: Can be associated with trisomy 18 and 21 or Aicardi syndrome 胎儿:可合并18,21三体综合征或Aicardi综合征。
Differential Diagnosis Intraventricular meningioma: Not likely given location and lack of homogenous enhancement. 脑室内脑膜瘤:本例不是脑室内脑膜瘤好发位置,且脑膜瘤强化为均匀强化。 Neurocysticercosis: Presents with cysts but not associated with choroid plexus. 脑囊虫病:一般表现为囊肿,但与脉络丛无明显相关。 Choroid plexus papilloma: Presents in children younger than the age of 5 as strongly enhancing lobulated intraventricular mass. 脉络丛乳头状瘤:一般发病于5岁以下儿童,表现为脑室内分叶状肿块,增强扫描明显强化。
Treatment Usually none. Can shunt for obstructive hydrocephalus. 一般无需治疗。如合并梗阻性脑积水,可以脑脊液分流治疗。
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