小脑多形性黄色星形细胞瘤临床病理分析

目的 分析和讨论发生在小脑的多形性黄色星形细胞瘤的临床病理特点。方法 采用免疫组织化学DAKO EnVison法、组织化学网质纤维染色和HE染色及形态学观察的方法，报道1例极罕见于年轻人小脑的多形性黄色星形细胞瘤，探讨其临床病理特点。结果 患18岁，以复视2个月就诊，CT显示小脑蚓部有圆形高密度影，组织学检查显示瘤细胞具有多形性，可见黄色瘤样细胞、多核或单核的巨细胞、Rothensal纤维和嗜酸性透明小滴。免疫组织化学染色显示瘤细胞胶质纤维酸性蛋白(GFAP)阳性，网质纤维染色显示单个瘤细胞间着色。结论 多形性黄色星形细胞瘤可发生在青年人小脑，极其罕见。结合形态学、组织化学和免疫组织化学特征，可以对这种罕见的星形细胞瘤作出正确的病理诊断。在小脑肿瘤的鉴别诊断中应该考虑到多形性黄色星形细胞瘤。

Clinicopathological analysis of pleomorphic xanthoastrocytoma in cerebellum

Objective To discuss the clinicopathological features of pleomorphic xanthoastrocytoma (PXA) in cerebellum.Methods We reported a case of PXA located in the cerebellum of a young adult in view of its extremely unusual location. Morphologic observation, immunohistochemical staining using DAKO EnVision system , histochemical stains including hematoxylin eosin (HE) and Gordon Sweet's reticulin methods were used.Results A 18 year old patient presented with 2 month's history of ambiopia. Computed tomography(CT) scan showed a round focus with high intensity and contrast enhancement in the cerebellar vermis. Histologic examination revealed pleomorphic cellular proliferation with xanthomatous, multi and mono nucleated giant cells. Rothensal fibers and eosinophilic hyaline granules were seen in the cytoplasm. Immunohistochemically, tumor cells showed reactivity to glial fibrillary acidic protein (GFAP). Reticulin staining revealed a fiber network surrounding individual tumor cells.Conclusion It is extremely unusual to find PXA in the cerebellum in young adults . To make a correct pathological diagnosis of this uncommon form of astrocytoma, analysis on combination of morphologic features , histochemical and immunohistochemical stains are necessary. This observation reinforces the argument that pleomorphic xanthoastrocytomas should be considered when making the differential diagnosis of cerebellar neoplasms .