非典型脑室外神经细胞瘤临床病理观察

Atypical extraventricular neurocytoma:a clinicopathological analysis

目的探讨非典型脑室外神经细胞瘤的临床病理特征。方法对1例非典型脑室外神经细胞瘤的临床表现、影像学、组织形态、免疫组化等进行分析并复习相关文献。结果患者男性,32岁。间断癫发作2年余。术前MRI提示右侧颞叶巨大囊实性占位。组织学上,瘤细胞为弥漫一致的中等大小透明细胞,其间可见小片状分布的神经毡样结构,细胞有一定异型性,核分裂象5个/10HPF,可见血管增生及栅栏样坏死。免疫组化显示瘤细胞Syn和S-100弥漫(+),少数瘤细胞GFAP、nestin和Neu-N(+),而Oligo-2、EMA、neurofilament和p53均(-),Ki-67约为20%。结论非典型脑室外神经细胞瘤临床上罕见,组织学形态上类似间变性少突细胞瘤、间变性室管膜瘤及多形性胶质母细胞瘤等,易误诊。特征性的组织学特点及免疫表型有助于鉴别。

Objective To explore the clinicopathologic characteristics of atypical extraventricular neurocytoma. Methods The clinical manifestations, image, histopathological features and immunohistochemical results were analyzed in one case of atypical extraventricular neurocytoma, with review of the related literatures. Results A 34-year-old man presented with two-year-long history of intermittent epileptic seizure. MRI scan revealed a large solid-cystic mass in right temporal lobe. Histologically, the tumor was composed of uniform medium-sized clear cells with small neuropil-like structures. The nucleus had slightly heteromorphism and the mitoses were about 5 per 10 high power field. Pseudopalisading necrosis and mierovaseular hyperplasia were also noticed. Immunohistochemieally, the tumor cells were positive for synaptophysin and S-100, focally positive for GFAP, Nestin and Neu-N, while negative for EMA, neurofilament, TP53 and Oligo2. The MIB-1 proliferative index was 20%. Conclusion Atypical extraventricular neurocytoma is a rare tumor, which is difficult to be distinguished histopathologieally from anaplastie oligodendroglioma, glioblastoma and anaplastic ependymoma, and so on. The characteristic hJstopathologieal features and immunohistochemical findings may help for differential diagnosis.