儿童脑原始神经外胚层肿瘤的CT、MRI和病理比较分析

Evaluation of CT and MRI findings and pathology of primitive neuroectodermal tumors in children

目的:儿童幕上原始神经外胚层肿瘤(PNETs)的影像学表现复杂,肿瘤可发生囊变、坏死、出血,与幕下髓母细胞瘤不同,本研究的目的是探讨幕上原始神经外胚层肿瘤的影像学表现特征。方法:对13例(男7例,女6例)儿童幕上PNETs患者的CT、MRI和病理资料进行回顾性比较分析。结果:13例患者中,4例肿瘤位于额叶,3例位于顶叶,2例位于颞叶,2例位于基底节区,1例跨居额顶叶区,1例位于枕叶。13例肿瘤中囊实性11例,囊性2例。肿瘤实性部分CT扫描呈略高密度,1例见点状钙化,肿瘤实性部分T1WI呈低或等信号,T2WI呈等高信号(9例)或高低等混合信号(4例),增强后均呈明显强化。肿瘤的囊壁CT扫描呈等密度,MRI呈等信号,1例囊壁增强后无强化。13例中,8例有瘤周水肿,5例无水肿。结论:儿童幕上PNETs多呈囊实性混合密度或信号肿块,实性部分CT扫描呈略高密度,T1WI呈低等信号,T2WI呈等高信号或高低等混合信号,增强后明显强化。肿瘤易发生囊变、坏死。

Objective： Supratentorial primitive neuroectodermal tumors（PNETs） tend to show a highly various heterogeneous features with an apparent areas of cystic degeneration, necrosis and hemorrhage which are different from medulloblastoma, The purpose of this study was to investigate imaging features of supratentorial PNETs. Methods： Clinical data, CT and MRI findings of 13 patients with PNETs were retrospectively analyzed. Results： CT and MR imaging demonstrated cystic and solid masses in 11 patients and cystic in 2 cases. Four tumors were located in the frontal lobes, 3 in the parietal lobes, 2 in the temporal lobes, 2 in the basal ganglion regions, 1 in the frontal and parietal lobes, and 1 in the occipital lobe. Imaging features were： （1）Mass lesion with large cystic or necrotic changes in 11 cases, the solid components of tumors were increased or decreased density when compared to surrounding normal brain tissue. （2）Mass with large central necrosis in 2 cases, the cystic wall of tumor was isodense. Punctate calcifications were seen in 1 case. In all patients, the solid components of tumors were isointense on T1WI and mild hyperintense on T2WI. Solid components of tumors were enhanced intensely. Of 13 patients, 8 had little peritumoral edema and 5 without peritumoral edema. Conclusion： Supratentorial PNETs has a more variable radiographic manifestations in children that characterized by： usually consist of solid and cystic components or only cystic, and solid portions usually show high density on CT, and iso-intense on T1WI and slight hyperintense on T2WI.