Koeller Kelly K, Sandberg Glenn D
Department of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
Radiographics. 2002 Nov-Dec;22(6):1473-505. doi: 10.1148/rg.226025118.
Intraventricular neoplasms are readily seen on cross-sectional images, but the myriad possibilities may make a focused differential diagnosis elusive. Consideration of the tissue within and composing the ventricular lining and the clinical findings provide the means to limit the differential diagnosis when analyzing an intraventricular mass on an imaging study. Ependymomas are typically calcified, are more common in children, are more common in the fourth ventricle, and show intense enhancement on contrast-enhanced images. Subependymomas and central neurocytomas have an affinity for the anterior portion of the lateral ventricle, and both commonly demonstrate a heterogeneous cystic appearance on cross-sectional images. Subependymomas are more common in older adults, whereas central neurocytomas are more common before 40 years of age. Subependymal giant cell astrocytomas always lie near the foramen of Monro and are characterized by frequent calcification, intense enhancement on contrast-enhanced studies, and the presence of other stigmata seen in tuberous sclerosis. When a mass is centered on the choroid plexus, a highly vascular tumor-either choroid plexus papilloma, choroid plexus carcinoma, meningioma, or metastasis-should be suspected. The characteristic heavily lobulated appearance of a choroid plexus tumor favors this diagnosis over other possibilities, although it is not always possible to distinguish between the more common benign form, the choroid plexus papilloma, and the less common malignant counterpart, the choroid plexus carcinoma. By using clinical, demographic, and imaging findings, one can significantly limit the differential diagnosis for many of the most common intraventricular neoplasms.
脑室内肿瘤在横断面图像上很容易被发现，但众多的可能性可能使针对性的鉴别诊断难以捉摸。在对影像学检查中的脑室内肿块进行分析时，考虑脑室内衬组织及其构成以及临床发现，可提供限制鉴别诊断范围的方法。室管膜瘤通常有钙化，在儿童中更常见，在第四脑室更常见，在增强图像上显示明显强化。室管膜下瘤和中枢神经细胞瘤好发于侧脑室前部，在横断面图像上两者通常表现为不均匀的囊性外观。室管膜下瘤在老年人中更常见，而中枢神经细胞瘤在40岁之前更常见。室管膜下巨细胞星形细胞瘤总是位于孟氏孔附近，其特征是频繁钙化、在增强检查中明显强化，以及存在结节性硬化症的其他特征表现。当肿块以脉络丛为中心时，应怀疑是高血管性肿瘤，即脉络丛乳头状瘤、脉络丛癌、脑膜瘤或转移瘤。脉络丛肿瘤典型的重度分叶状外观支持该诊断而非其他可能性，尽管通常无法区分较常见的良性形式脉络丛乳头状瘤和较罕见的恶性对应物脉络丛癌。通过综合临床、人口统计学和影像学表现，对于许多最常见的脑室内肿瘤，人们可以显著缩小鉴别诊断范围。
