颅内原始神经外胚层肿瘤的MRI表现及病理分析  

MRI Features and Histopathological Analysis of Intracranial Primitive Neuroectodermal Tumors

作　　者：刘香[1] 张嘉君[1] 赵茜茜[1] 黄丽霞[1] 许乙凯[1] 

机构地区：[1]南方医科大学南方医院影像中心,广州硕士研究生510515

出　　处：《临床放射学杂志》2014年第6期822-827,共6页Journal of Clinical Radiology

摘　　要：目的探讨颅内原始神经外胚层肿瘤(primitive neuroectodermal tumors,PNET)的MRI及病理特征,以期提高对该病的认识。方法回顾性分析17例经病理证实的颅内PNET的MRI及病理表现。结果 1例仅表现为瘤性脑脊膜炎。16例为颅内单发肿块,其中位于侧脑室周围脑叶内(9例)及幕上脑室内(2例)者体积较大,囊变坏死多;近中线区如基底节及丘脑(3例)、桥臂及松果体区(各1例)肿瘤体积较小,囊变坏死少;肿块多呈类圆形、偏实性、边界较清、瘤周水肿轻或无,实质信号似脑灰质、瘤内因出血(10例)、钙化(2例)及囊变(14例)而信号混杂;增强3例呈多发不规则环形强化,1例轻度强化,余呈明显不均一强化,且3例发生脑脊液播散。病理上,瘤组织由致密小圆细胞构成,浸润性生长,部分形成菊形团,免疫组织化学示多种神经源性标记物阳性表达;其中髓上皮瘤2例,室管膜母细胞瘤1例,神经母细胞瘤1例,未具体分型者PNET 13例。结论颅内PNET的影像表现有一定特点,MRI有助于该病的诊断和指导治疗,确诊仍依赖病理。Objective To evaluate the MRI and pathological features of intracranial primitive neuroectodermal tumors （PNET） and improve the diagnosis. Methods The MRI appearances and their pathological features of 17 patients with pathologically proven intracranial PNET were analyzed retrospectively. Results Carcinomatous meningitis was found in brain and spinal cord in 1 case. The other 16 cases showed single intracranial mass. The tumors arised from lobes surrounding bilateral ventricles in 9 cases, supratentorial ventricles in 2 cases, basal ganglia and thalamus in 3 cases, pedunculus cerebellaris medius in 1 case. The tumors commonly showed round and sharply marginated with little peritumoral edema. The solid part was iso intensity to grey matter signal,or mixed signal due to variable foci of hemorrhage（ 10 cases）, calcification（2 cases）and cystic change（ 14 cases）. On contrast images, irregular rim enhancement was showed in 3 cases, slightly enhancement in 1 case, marked inhomogeneous enhancement in the other cases. Tumor disseminating along cere- brospinal fluid was found in 3 cases. On pathological images, the malignant neoplasms consisted of crowded undiferentiated small round cells and spread invasively, some of the tumor cells appeared as rosettes. The immunohistochemistry assay showed positive expression of multiple neurogenous maker. Pathologically, 2 cases of medulloepithelioma were identified, along with 1 ependymoblastoma and 1 neuroblastoma,the other 13 cases were not specifically defined. Conclusion Certain imaging features may suggest the diagnosis of intracranial PNET. MRI is an effective technique in detecting this tumor and is helpful to treatment planning and follow up. The final diagnosis relies on pathology and immunohistochemistry.

关 键 词：神经外胚层肿瘤 原始 脑肿瘤 磁共振成像 病理学 

分 类 号：R739.4[医药卫生—肿瘤]