19例透明隔区肿瘤与肿瘤样病变的影像表现与分析

The Imaging Features of Tumors or Tumor-like Lesions in Septum Pellucidum

目的探讨透明隔区肿瘤与肿瘤样病变的影像学特点。资料与方法分析经手术病理证实的19例透明隔肿瘤与肿瘤样病变的影像表现。男7例,女12例。原发性16例,继发性3例。术前仅行MRI检查者11例,CT检查3例,既行CT检查又行MRI检查者5例。结果 (1)16例原发性肿瘤或肿瘤样病变完全依附于透明隔,其中14例突向一侧脑室生长。3例继发肿瘤大部附着于透明隔,其余位于胼胝体、尾状核或丘脑;(2)透明隔肿瘤及肿瘤样病变一般以混杂信号为主(13例),T1WI、T2WI呈混杂信号,中枢神经细胞瘤(CNC)(4例)、少突胶质细胞瘤(OLG)(1例)及淋巴瘤(1例)在扩散加权成像(DWI)序列上呈高信号,增强后病变轻度强化1例,中度强化6例,明显强化6例。(3)原发性透明隔肿瘤以囊实性为主,CNC、室管膜下巨细胞星形细胞瘤(SGCA)、室管膜下瘤及生殖细胞瘤一般呈小囊,星形细胞瘤、室管膜瘤及OLG呈大囊;继发性肿瘤中淋巴瘤(2例)一般为实性,星形细胞瘤(1例)呈大囊型。(4)其他表现有钙化(5例)、出血(2例)及灶周水肿(3例)。结论根据病变与透明隔的位置关系可推断其来源,肿瘤或肿瘤样病变的信号/密度、囊变大小、钙化及瘤周水肿等影像表现有助于定性诊断。

Objective To discuss the imaging features of tumors and tumor-like lesions in septum pellucidum.Materials and Methods The imaging features of 19 patients（7 males and 12 females） with tumors or tumor like lesions in septum pellucidum were reviewed retrospectively.The pathology proved primary tumors or tumor-like lesions in 16 cases,metastatic tumors in 3 cases.Eleven patients performed MRI examination,3 patients performed CT scan,and 5 patients performed both MRI ang CT examination before operation.Results（1） Sixteen lesions of primary tumors or tumor-like lesions were completely attached to septum pellucidum.Among them,14 lesions protruded into unilateral ventricle.The 3 metastatic tumors were mostly attached to septum pellucidum with small parts located in the corpus callosum,caudate nucleus or thalamus.（2） The tumors and tumor-like lesions in septum pellucidum usually showed mixed signal intensity.On DWI,CNC,OLG and lymphoma often showed high signal intensity.After injection of Gd-DTPA,the lesions showed mild enhanced in one lesion,moderately enhanced in six lesions,and obviously enhanced in 6 lesions.（3） The primary tumors were cystic-solid lesions.Among them,Central neurocytoma,subependymal giant cell Astrocytoma,subependymal tumor and germ cell tumors displayed as small-cyst pattern,while astrocytoma,ependymoma,and oligodendrocytes displayed as larger cyst.Among the metastatic tumors,lymphoma displayed as solid pattern and astrocytoma displayed as big cyst.（4） The other fatures of lesions included calcification in 5 cases,hemorrhage in 2 cases and peritumoral edema in 3 cases.Conclusion The origin of the lesions could be identifyed by the relation between the lesions and the septum pellucidum.The imaging features,such as heterogeneous signal/ density,cystic-solid pattern,calcification and peritumoral edema,contribute to the final diagnosis.