Yamada Shoko M, Murakami Hideki, Tomita Yusuke, Nakane Makoto, Shibui Soichiro, Takahashi Mikiko, Kawamoto Masashi
Department of Neurosurgery, Teikyo University Mizonokuchi Hospital, 3-8-3 Mizonokuchi, Takatsu-ku, Kawasaki, Kanagawa, 213-8507, Japan.
Department of Diagnostic Pathology, Teikyo University Mizonokuchi Hospital, 3-8-3 Mizonokuchi, Takatsu-ku, Kawasaki, Kanagawa, 213-8507, Japan.
Diagn Pathol. 2016 Jul 22;11(1):65. doi: 10.1186/s13000-016-0514-2.
Pleomorphic xanthoastrocytoma (PXA) with anaplastic features should be strictly distinguished from glioblastoma multiforme (GBM).
A case of PXA that was initially diagnosed as GBM is presented. A 42-year-old man visited our clinic because of right hemiparesis and total aphasia. Head magnetic resonance imaging demonstrated enhanced multiple cystic lesions in the left temporal lobe suggesting an intra-parenchymal brain tumor. The lesion was partially removed and GBM with a Ki-67 index of 20 % was diagnosed by pathological examination of the resected specimen. Despite receiving radiation and chemotherapy, the patient died 6 months after the first admission. At autopsy, the boundary between the tumor and normal brain tissue was clear. Large parts of the tumor demonstrated typical features of PXA, including pleomorphism, clear xanthomatous cells with foamy cytoplasm, positive silver staining, and a Ki-67 index of less than 1 %.
GBM should be diagnosed only when the majority of the tumor cells are undifferentiated. Although the operative specimen appeared typical GBM histologically, the diagnosis of GBM was subsequently excluded by the autopsy finding that much of the tumor had the characteristic features of a benign PXA. Therefore, the final diagnosis in this case was PXA with anaplastic features. PXA with anaplastic features should be carefully distinguished from GBM to facilitate appropriate decisions concerning treatment.
具有间变特征的多形性黄色星形细胞瘤（PXA）应与多形性胶质母细胞瘤（GBM）严格区分。
本文报告一例最初被诊断为GBM的PXA病例。一名42岁男性因右侧偏瘫和完全性失语前来我院就诊。头部磁共振成像显示左侧颞叶有多个强化囊性病变，提示脑实质内肿瘤。病变部分切除，切除标本的病理检查诊断为Ki-67指数为20%的GBM。尽管接受了放疗和化疗，患者在首次入院后6个月死亡。尸检时，肿瘤与正常脑组织之间的边界清晰。肿瘤的大部分表现出PXA的典型特征，包括多形性、具有泡沫状细胞质的透明黄色瘤细胞、银染色阳性以及Ki-67指数小于1%。
仅当大多数肿瘤细胞未分化时才可诊断为GBM。尽管手术标本在组织学上表现为典型的GBM，但尸检发现肿瘤的大部分具有良性PXA的特征，随后排除了GBM的诊断。因此，该病例的最终诊断为具有间变特征的PXA。具有间变特征的PXA应与GBM仔细区分，以便做出合适的治疗决策。
