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SUMMARY
Often Occurs in middle-aged men 好发于中年男性 fourth ventricle and lateral ventricle 多位于四脑室和侧脑室 Mass, clearly edge 团块状、边缘较清楚 no or slight Enhanced 增强扫描后，多无强化或轻微强化
特征性表现：条带
T2等、高信号 T1等低信号 T2上所见的高信号条
带为内分子层、颗粒 细胞层，以及白质细 胞丢失所致
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Dysplastic Cerebellar Gangliocytoma
Imaging Findings-MRI
Dysplastic cerebellar gangliocytoma in a 47-year-old woman. (a)Axial T1weighted MR image shows a cerebellar mass with a striped appearance. (b)Axial T2-weighted MR image shows the same laminar morphology, composed of alternating hyperintense and isointense bands. (c) Con-trastenhanced axial T1-weighted MR image shows no enhancement of the mass1.2/64
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Dysplastic Cerebellar Gangliocytoma
Pathologic Findings
disruption of the normal cerebellar laminar structure
hypertrophic ganglion cells
granular and molecular layers of the cerebellar cortex
Imaging Findings-MRI
1.5T SWI MIP图像显示瘤周引流静脉，7T SWI MIP图像显示瘤 周大量引流静脉及齿状核受压
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Dysplastic Cerebellar Gangliocytoma
Imaging Findings-MRI
图1 MRI平扫轴位T1WI(A)，增强扫描轴位T1WI(B)，左侧小脑半球可见一团 块状长T1、长T2异常信号影，边界清楚，其内信号不均匀，可见条纹状等T1、 T2信号影。增强扫描未见明显强化。图2 各向异性分数（fractional anisotropic, FA）灰度图，肿瘤区域呈低信号。图3 ADC图，肿瘤区域呈等及稍 高信号
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PART TWO
Adult Tumors of the Posterior Fossa
Hemangioblastoma 血管母细胞瘤，血管网状细胞瘤（血网） Dysplastic Cerebellar Gangliocytoma 发育不良性神经节细胞瘤 Subependymoma 室管膜下瘤
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Dysplastic Cerebellar Gangliocytoma
Pathologic Findings
免疫组化染色显示神经元 特异性蛋白酶及突触素阳
性表达
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Dysplastic Cerebellar Gangliocytoma
Imaging Findings-CT
NCCT usually hypoattenuated may be isoattenuated Calcification is
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Dysplastic Cerebellar Gangliocytoma Goal of therapy
Decompression of the ventricular system 解除脑室系统的压迫 difficult visualization: gradual change from normal cerebellar tissue to the abnormal tissue 正常脑组织与瘤组织分界不清 impairs a complete resection 难以完整切除 most patients do well following surgical resection 大多数患者预后良好 some have recurrence after a prolonged disease-free interval 少数患者经过一段静止期后仍可复发
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Subependymoma
Incidence and Clinical Presentation
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Subependymoma
Incidence and Clinical Presentation
rare, benign, slowgrowing tumor generally well-circumscribed sometimes multiple lesions most frequently: fourth ventricle distinctive histologic appearance histogenesis: contrinical Presentation
commonly symptoms increased intracranial
pressure
hydrocephalus Megalencephaly mental retardation
duration of symptoms considerable variability
confirmation
typical appearances 1. unilateral cerebellar mass 2. non-enhancing 3. middle-aged patient 4. tiger-striped pattern
MRI是诊断的最佳方式 特征性表现 几乎可在不需要病理证实
的条件下做出明确诊断
四条特征 1. 单侧半球肿块 2. 不强化 3. 成年患者 4. 虎斑征
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Dysplastic Cerebellar Gangliocytoma
Imaging Findings-MRI
characteristic: bands hyperintensity and
asymptomatic
常见临床症状 颅内压增高 脑积水 巨脑畸形 精神障碍 症状时间 不定 甚至也可无症状
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Dysplastic Cerebellar Gangliocytoma VS
Cowden disease
Clinical Presentation
Cowden disease autosomal dominant hamartoma syndrome
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Subependymoma
Incidence and Clinical Presentation
1945年由Scheinker首次报道 占颅内全部肿瘤的不足1% 大多数学者认为室管膜下瘤是室管膜瘤的一种类型 室管膜下瘤、中枢神经细胞瘤、室管膜下巨细胞星 形细胞瘤Subependymoma, central neurocytoma, subependymal giant cell astrocytoma具有相同的起源， 均起源于室管膜下的具有双向分化潜能的神经胶质 祖细胞Glial progenitor cells
良性肿瘤，生长缓慢 通常边界清楚 可为多发 常见于四脑室 病理学表现典型 组织学发生有争议
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Subependymoma
Incidence and Clinical Presentation
arises from: subependymal glial layer
asymptomatic, incidentally at autopsy (0.4%)
increased myelination in the molecular layer
Mitotic activity and necrosis are uncommon
正常小脑板层结构破坏 大量增生肥大的神经节 细胞 侵蚀小脑皮层的颗粒层 和分子层 分子层髓鞘化增加 病理组织切片上有丝分 裂活性及坏死少见
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Dysplastic Cerebellar Gangliocytoma
Pathologic Findings
×100
×200
hypertrophic ganglion cells expanding the granular and molecular layers of the cerebellar cortex
isointensity on T2
isointense and hypointense
on T1
hyperintense signal on T2
corresponds to the inner molecular layer, granular cell layer, and loss of central white matter
uncommon
Thinning of the skull
CT平扫 常为低密度 但也可为等密度 无特异性 诊断困难 钙化少见 偶可见颅板变薄
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Dysplastic Cerebellar Gangliocytoma
Imaging Findings-MRI
MRI：best imaging modality characteristic appearance without histopathological
Males more commonly
Most cases (82%) older than 15 years