非典型脑室外神经细胞瘤临床病理观察

Atypical extraventricular neurocytoma: a clinicopathologic observation

[目的]探讨非典型脑室外神经细胞瘤临床病理特征,以提高对该肿瘤的认识。[方法]对1例非典型脑室外神经细胞瘤进行形态学和免疫组化观察,并结合临床资料复习相关文献。[结果]镜下可见肿瘤由一致的小至中等大小的圆或类圆形细胞构成,细胞质量中等空亮淡染,部分细胞胞质粉染,核圆或卵圆、居中。部分区域细胞密集并出现一定异型性,核分裂5个/10HPF,并可见病理性核分裂。可见单细胞坏死及神经节样细胞。血管增生明显。免疫组化:瘤细胞Syn、S-100及NSE弥漫(+),p53和GFAP灶状(+),ki-67>30%,CD3、CK、CD20、LCA、actin、desmin、HMB45、melan-A、Cg-A、EMA、nestin、NF及Vimentin均(-)。[结论]非典型脑室外神经细胞瘤非常罕见,诊断关键在于形态学特点结合免疫组化结果。

[Objective] To investigate the clinicopathological characteristics of atypical extraventricular neurocytoma and to make the acquaintance of it.[Methods] One case of atypical extraventricular neurocytoma was observed with the morphorlogical method,clinical data analysis and review of the related literature.[Results] Morphologically,the tumor was composed of uniform small-to-medium-sized cells with clear and partly eosinophilic medium cytoplasm and oval to round and central located nuclei.There were mild-to-moderate nuclear pleomorphism and focal anaplasia with increased mitotic activity,up to 5 per 10 HPF,as well as the pathologic mitosis.Single-cell necrosis and ganglionic differention were also noticed.Vascular hyperplasia was present.Immunohistochemically,the tumor cells were positive for syn,S-100 and NSE,focally positive for GFAP and p53,while negtive for CD3,CK,CD20,LCA,actin,desmin,HMB45,melan-A,Cg-A,EMA,nestin,NF and Vimentin.The MIB-1 proliferative index was over 30%.[Conclusioin] Atypical extraventricular neurocytoma is extremely rare.The definite diagnosis depends on the histopathological features and immunohistochemical findings.