脑内脱髓鞘假瘤病理、临床与磁共振成像对照分析

Comparison between pathologic, clinical and MRI findings of demyelinating pseudotumor in brain

目的探讨脑内脱髓鞘假瘤的MR影像学表现并分析其病理、临床与MRI影像三者之间的相关性。方法回顾性分析总结经病理证实的8例病例的病理、临床及MRI表现并加以对照。结果临床表现以肢体运动障碍和（或）肢体感觉障碍最常见，亦可见癫痫等少见症状。MRI影像显示病灶均单发、以侵犯皮层下白质为主，“瘤体”多为圆形或类圆形、边界多较清楚．信号多为TI均匀低信号、T2均匀高信号，多明显均一强化，多有明显占位效应及灶周水肿。病理上病变处脑组织脱髓鞘，轴索尚保存。见大量淋巴细胞在血管周围围绕浸润呈套袖现象．此外尚可见大量的巨噬细胞以及胶质细胞增生。结论脑内脱髓鞘假瘤病理、临床与MRI影像的相关性较好，MRI是其诊断的重要依据。其发生于幕上时与胶质瘤鉴别诊断相对较易，发生于幕下时与Ⅰ～Ⅱ级胶质瘤不易鉴别，此时应密切结合临床。对于临床与影像学诊断均较困难者，可行肾上腺皮质激素试验性治疗或脑组织活检。

Objective To analyze the MRI findings and study the correlations between pathologic, clinical and MRI findings ofdcmyclinating pscudotumor in brain. Methods Pathologic, clinical and MRI findings in 8 cases proved pathologically with dcmyelinating pscudotumor in brain wcrc retrospectively analyzed. Results The clinical manifestations comprised mostly dyskincsia and/or limb sensory disability, as well as epilepsy in few cases. MRI showed a single focal lesion mainly invading subcortical white matter in every case, and most lesions wcrc showed round or nearly round with clear boundary, homogenous low signal on T1WI and high signal on T2WI, and marked enhancement. Pathological examination showed dcmyclinating, pcrivascular inflammatory infiltration consisting predominantly of lymphocytcs, and glial cell proliferation. Conclusions MRI can well mirror the pathological and clinical changes of dcmyclinating pscudotumor in brain, so MRI plays an important role in its diagnosis. It is easy to make a differential diagnosis between glioma and supratentorial dcmyclinating pscudotumor, but it is difficult for those lesions in cerebellum. For such cases, both clinical and MRI diagnosis arc necessary. Trial treatment of corticoids or even biopsy is available for those cases that arc difficult to diagnose by clinical and MRI methods