脑膜间质非脑膜上皮细胞肿瘤

Meningeal Mesenchymal Non-Meningothelialtumors

脑膜间质非脑膜上皮细胞瘤是一组起源于脑膜 ,呈现为纤维、纤维组织细胞、脂肪、肌样、内皮、软骨或骨组织表现 ,但无脑膜上皮分化的脑膜的良、恶性肿瘤。其中以血管外皮细胞瘤 (Ⅱ级或Ⅲ级 )和脂肪瘤 (良性 )相对常见 ,其他类型肿瘤则罕见。血管外皮细胞瘤的影像学表现类似于有坏死、囊变而无钙化倾向的良、恶性脑膜瘤。颅内脂肪瘤典型的发生部位在中线结构 ,如胼胝体、四叠体、桥小脑角 ,脂肪瘤表现为T1WI呈高信号 ,脂肪抑制序列上高信号可被抑制。其他罕见肿瘤很难在病理学检查前得出正确诊断。

Meningeal mesenchymal, non-meningothelial tumors are a group of benign and malignant tumors originating in the meninges showing fibrous, fibrohistiocytic, adipose, myoid, endothelial, chondroid or osseous, but not meningothelial defferentiation. Among them only hemangiopericytoma (grade II or III) and lipoma (benign) are relatively common, and others are very rare.Imaging of hemangiopericytoma is similar to which of bening or malignant meningioma having a tendency of necrosis and cystic change without calcification. Intracranial lipomas typically occur at midline sites, such as around the corpus callosum and quadrigeminal plate, and cerebellopontine angle. Lipoma appears hyperintense on T1WI images and the high signals can be suppressed by fat suppression procedures. Other rare tumors are very difficult to be diagnosed before pathological examination. Images from eight cases of these rare tumors are showed.