多形性黄色瘤型星形细胞瘤9例临床病理分析

Pleomorphic xanthoastrocytoma: a clinicopathological analysis of 9 cases

目的观察脑部少见的多形性黄色瘤型星形细胞瘤(PXA)的临床病理特点。方法复习9例此类肿瘤的临床病理资料及相关文献,并做GFAP,EMA,vimentin,Ki-67等免疫组化检测。结果患者平均年龄17.7岁。4例位于颞叶,影像学及手术均揭示病变紧邻脑膜;4例以癫为主要症状。组织学上,均可见黄瘤样细胞及核内包涵体、颗粒状小球,8例均有多少不等的淋巴细胞浸润并形成血管周袖套样结构;6例见多核巨细胞,3例见Rosenthal纤维,2例有钙化,均未见分裂象和血管内皮细胞增生。免疫组化GFAP、vimentin(+),EMA(-),Ki-67≤5%。结论PXA是一种少见的具有特殊临床病理特点的、预后良好的星形细胞来源的肿瘤。避免误诊的关键是认清其诊断陷阱,应对策略是临床、影像、病理三结合。

Objective To investigate the clinicopathological features of a rare type of brain tumor-pleomorphic xanthoastrocytoma （PXA）. Methods The clinical data, pathological changes and findings of immunohistochemistry were studied in 9 cases with review of the literatures. Results The average age at the time of surgery of 9 patients was 17.7 years old. All lesions were closed to dural meninges and that of 4 cases located at temperal lobe. The chief symptoms of four cases were epilepsy. Histologically, pleomorphic and lipidized cells, nuclear inclusions and granular bodies were seen. There were lymphocyte infiltration in eight cases, muhinucleated giant cells in six cases, Rosenthal fibers in three cases and calcifications in two cases. Mitotic figures and endothelial proliferations were not observed in all cases. Tumor cells were positive for GFAP, vimentin, and no more than 5% positive for Ki-67, but negative for EMA. Conclusions Pleomorphic xanthoastrocytoma of central nervous system is a rare astrocytic tumor with specific clinicopathologic features, most of which have a favorable prognosis. We should recognize its the pitfalls of diagnosis, and combine clinical history, image features with microscopic findings to avoid misdiagosis.