外周性神经源性肿瘤的MRI表现与病理基础研究

目的　分析外周性神经源性肿瘤的MRI表现。方法　对 2 5例神经源性肿瘤 (良性 19例 ,恶性 6例 )进行组织学观察 ,分析其与MR表现之间的关系及良恶性肿瘤的MRI鉴别诊断。结果　神经鞘瘤 14例 ,神经纤维瘤 5例 ,恶性周围性神经鞘瘤 (MP NST) 5例 ,原始神经外胚层瘤 1例。起源于神经干的肿瘤常呈纺锤形 ;肿瘤信号多欠均匀 ,T2 WI呈“靶征”者 3例 ,2例神经鞘瘤靶心有较多纤维组织 ,靶周明显水肿、粘液变性 ,1例MPNST靶心有较多纤维组织和部分钙化。 2例MPNST破坏骨质。结论　肿瘤的部位、形态和信号对诊断有较大帮助 ,恶性肿瘤可伴灶周水肿并可破坏邻近骨质。

MRI Appearances and Their Pathologic Basis of Peripheral Neurogenic Tumors

Objective To analyse the MRI findings of peripheral neurogenic tumors.Methods The histologic examinations were reviewed in 25 cases with peripheral neurogenic tumors(19 benign,6 malignant),and their correlations with the MRI appearances were further evaluated.The differential diagnosis between the benign and malignant tumors was also discussed.Results There were 14 schwannomas,5 neurofibromas,5 malignant peripheral nerve sheath tumors(MPNST),and 1 peripheral primitive neuroectodermal tumor.The signal intensity of the most neurogenic tumors was nonhomogeneous.The target appearance was seen in only 2 schwannomas and 1 NPNST,in which the central zone of them composed of tightly packed fibers accompanied by areas of calcification in the latter,the peripheral zone of the tumors composed of loosen mucus.Bone structure were destructed in 2 MPNST.Conclusion The location,shape,and signal intensity of the tumor are very important in the diagnosis of the peripheral neurogenic tumors.The malignant tumor should be deduced when the edema around the lesion and nearby bony destruction are found.