三例貌似脑炎的幕上原始神经外胚层肿瘤的临床病理分析

目的分析幕上原始神经外胚层肿瘤(s-PNET)的临床、影像学和病理特点,以期早期诊断,早期治疗,从而改善预后。方法回顾分析3例临床上貌似脑炎的s-PNET的临床资料、脑脊液细胞学、头颅核磁共振和脑活检组织病理学特点。结果本文3例患者起病相对较急,主要表现颅高压的症状和局灶神经系统症状,如单肢或偏侧肢体无力,或癫痫发作等。例1脑脊液细胞学可见异形细胞,符合肿瘤细胞。3例患者影像学上病灶边界不清晰,无明显强化。随病情发展,病灶局部扩大或者蔓延至对侧,甚至出现脑脊液播散,并且局部囊性变。3例肿瘤组织绝大部分均由原始幼稚的小细胞构成,弥漫浸润性生长,可见Homer Wright菊形团形成。3例肿瘤细胞一致性表达CD99、Syn、NSE、Nestin和S-100,散在表达CgA、GFAP、NeuN和oligo-2;Ki-67阳性率40%～60%。结论 s-PNET临床和影像学表现多样,确诊需要脑组织病理诊断。

Clinical and pathological analysis of three cases of Supratentorial primitive neuroectodermal tumors mimicing encephalitis

Objective To analyze the clinical features,radiological presentations and pathological characteristics of supratentorial primitive neuroectodemal tumors(s-PNET) for early diagnosis and therapy in order to ameliorate the prognosis.Methods The various clinical presentations,cytology of cerebral spinal fluid(CSF),neuroimage and histopathological characteristics of three cases of s-PNET mimicing encephalitis were retrospectively reviewed.Results The most common clinical presentations were increased intracranial pressure and localized neurological symptoms such as monoplegia,hemiparesis or seizures with acute onset.Heterotypic cells coincidence with tumor cells were found on cytology of CSF of case1.Definite mass was not found radiologically and the foci with ill-defined margins were not enhanced.As disease progressed,the foci enlarged or spread to the contralateral side with cystic formation,even CSF dissemination was found.The tumor consisted of small undifferentiated cells which infiltrated the peripheral tissue diffusely and Homer-Wright rosettes were also observed.The tumor was consistently positive for CD99,synaptophysin(Syn),neuron-specifi c enolase(NSE),Nestin,S-100.The tumor cells night scattered in expression of chromograninA(CgA),glial fibrillary acidic protein(GFAP),neuronal nuclei(NeuN),oligonucleotide-2;Immunohistochemical stain for Ki67 ranged between 40%-60%.Conclusion The clinical and radiological presentations of s-PNET Varies.Brain biopsy is necessary for definite diagnosis.