青少年多形性低级别神经上皮肿瘤的多模态MRI特征分析:5例病例复习

Multimodal Magnetic Resonance Imaging Features of Polymorphous Low-gradeNeuroepithelial Tumor of the Young:A Case Series of 5 Cases

目的 探究青少年多形性低级别神经上皮肿瘤(PLNTY)的常规MRI表现及多模态MRI特征,以提高对该罕见肿瘤的认识。方法 回顾性分析5例经手术病理确诊的PLNTY患者的临床及影像学资料。所有患者均接受MRI增强扫描,其中3例行MRI多模态扫描,1例另行头部CT检查。结果 3例男性和2例女性,中位年龄25岁,4例表现为癫痫。常规MRI示4例位于颞叶,1例位于顶叶;平均最大径约1.76 cm(1.1~3.7 cm);3例T2WI呈现“椒盐征”,3例可见钙化、囊变和不同程度强化。多模态MRI示5例均无扩散受限;磁敏感加权成像(SWI)示2例病灶内钙化,磁共振波谱成像(MRS)示N-乙酰天门冬氨酸(NAA)/胆碱(Cho)倒置;扩散张量成像(DTI)示白质纤维束受侵犯或压迫;灌注加权成像(PWI)示病灶区域灌注轻度增高。结论 PLNTY好发于年轻成人,以颞叶皮层下常见,常伴钙化和囊变。T2WI“椒盐征”可能是其特征性表现。多模态MRI提示其为低级别胶质瘤。PLNTY确诊需依靠病理学检查,但以上特征有助于鉴别诊断。

Objective To investigate the conventional MRI and multimodal MRI features of polymorphous low-grade neuroepithelial tumor of the young(PLNTY)to enrich our knowledge about this rare tumor type.Methods A retrospective analysis of clinical and radiological data was conducted on five patients with surgically and pathologically confirmed PLNTY.All patients underwent enhanced MRI scans,with three of them receiving multimodal MRI,and one patient undergoing head CT examination.Results The case series included three males and two females with a median age of 25 years.Four patients presented with epilepsy.Conventional MRI revealed that four tumors were located in the temporal lobe and one in the parietal lobe;the average maximum diameter was approximately 1.76 cm(ranging from 1.1 to 3.7 cm).Three cases exhibited the“salt and pepper”sign on T 2WI,with calcifications,cystic changes,and varying degrees of enhancement observed in three cases.Multimodal MRI demonstrated that none of the five cases showed diffusion restriction;susceptibility-weighted imaging(SWI)identified calcifications within the lesion in two cases;magnetic resonance spectroscopy(MRS)showed inversion of the NAA/Cho ratio;diffusion tensor imaging(DTI)revealed invasion or compression of white matter fiber tracts;and perfusion-weighted imaging(PWI)demonstrated a mild increase in perfusion within the lesion areas.Conclusion PLNTY predominantly affects young adults and are commonly located in the subcortical area of temporal lobe,often accompanied by calcifications and cystic changes.The“salt and pepper”sign on T 2WI may be a characteristic feature.Multimodal MRI indicates its nature as a kind of low-grade glioma.Pathological examination is essential for the diagnosis of PLNTY,but the aforementioned features can assist differential diagnosis.