探讨伴菊形团结构脑膜瘤的临床病理特征、免疫表型、诊断及鉴别诊断。

分析1例伴菊形团样特征且合并颅骨侵犯的非典型脑膜瘤的临床病理学及影像学资料，并复习相关文献。

患者男性，56岁，体检行头颅MRI示顶部颅骨下见不规则团块状软组织影。病理检查见肿块共计11.0 cm×9.5 cm×1.5 cm，破坏骨组织。镜下见肿瘤由梭形细胞和上皮样细胞组成，显著特征为可见的弥漫性分布的大菊形团结构，中央形成嗜伊红的少细胞区，部分菊形团由细长的肿瘤细胞呈放射状排列而成，其内未见明显血管样腔隙结构。免疫组织化学染色显示肿瘤细胞EMA、SSTR2a、Vimentin、PR、E-cadherin、D2-40、p53阳性，GFAP、S-100、STAT6、CD99、bcl-2、Fli-1、NSE、Syn、CD45、Melanoma、SATB2均为阴性。二代测序显示NF2基因第四外显子突变和MGMT启动子甲基化。

伴菊形团样结构特征的脑膜瘤罕见，其诊断主要依赖典型的脑膜上皮分化区域及免疫组化，在低分化病例中出现菊形团样结构时，应考虑脑膜瘤的可能性。

To investigate the clinicopathological features, immunophenotype, diagnosis, and differential diagnosis of meningioma with rosettes.

The clinical, pathological, and imaging data of an atypical meningioma with rosettes with skull invasion were analyzed and the relevant literature was reviewed.

A 56-year-old male patient underwent a head MRI scan showing an irregular massive soft tissue shadow under the top skull. On pathological examination, the mass measured 11.0 cm×9.5 cm×1.5 cm, which destroyed the bone tissue. Microscopically, the tumor was composed of spindle cells and epithelioid cells. It was characterized by the diffuse distribution of rosettes, with the eosinophilic and oligocellular zone in the center. Some of rosettes were composed of elongated slender tumor cells, and there was no obvious vessel-like cavum structure in it. Immunohistochemical staining revealed that the tumor cells were positive for EMA, SSTR2a, Vimentin, PR, E-cadherin, D2-40, and P53, but negative for GFAP, S-100, STAT6, CD99, Bcl-2, Fli-1, NSE, Syn, CD45, Melanoma, and SATB2. Second-generation sequencing revealed a mutation in the fourth exon of the NF2 gene and MGMT promoter methylation.

Meningioma with rosettes is rare, and its diagnosis mainly depends on the presence of typical meningoepithelial differentiation region and immunohistochemistry. When rosette-like structure appears in poorly differentiated cases, meningioma should be considered.