颅内原发性上皮样平滑肌肉瘤临床病理分析

Clinicopathological features of primary intracranial epithelioid leiomyosarcoma

目的 探讨颅内原发性上皮样平滑肌肉瘤(primary intracranial epithelioid leiomyosarcoma, PIELMS)的临床病理学特征及鉴别诊断要点。方法 收集1例PIELMS临床及影像学资料、观察其病理学形态及免疫表型,并复习相关文献,探讨该肿瘤的病理诊断和鉴别诊断要点。结果 患者,女性,39岁,发生于双侧脑室体部,因脑室肿瘤术后9个月复发入院。镜下观察肿瘤呈浸润性生长,由上皮样细胞组成,上皮样细胞不规则排列,局部呈条索状,可见大片凝固性坏死,上皮样细胞胞质丰富,嗜酸性,细胞核大小不一,细胞核呈圆形、卵圆形、不规则形,核染色质细腻,可见核分裂象。免疫组化结果:瘤细胞SMA、Desmin、Caldesmon、Vimentin、CD99、Nestin呈阳性表达,GFAP、OLIG-2、CD34、Bcl-2、CD163、CD31、CK20、CK7、ERG、FⅧ、GATA-3、HMB45、MelanA阴性,Ki-67阳性比例20%。结论 PIELMS是一种极罕见的颅内原发性间叶性肿瘤,需要与室管膜下巨细胞瘤、室管膜瘤及上皮样胶质母细胞瘤鉴别,其确诊需结合组织病理学及免疫组化表型。

Objective To investigate clinicopathologic features and differential diagnosis of primary intracranial epithelioid leiomyosarcoma(PIELMS). Methods The clinical and radiological data were collected in a case of PIELMS, and its pathological and immunohistochemical features were analyzed, and the tumor’s pathological diagnosis and differential diagnosis were analysed based on review of related literature. Results The age of the female patients at diagnosis was 39 years. The lesion was located in the bilateral ventricles. The patient was admitted to the hospital because of tumor recurrence 9 months after surgery. Microscopically, the tumor showed invasive growth, which was composed of epithelioid cells. Epithelioid cells were arranged irregularly, or in cord focally. Coagulative necrosis was seen. Epithelioid cells were rich in eosinophilic cytoplasm, and nuclei were variable in size, and round, oval, and irregularly shaped. The nuclear chromatin was fine with high mitotic activity. Immunohistochemical staining showed SMA, Desmin, Caldesmon, Vimentin, CD99 and Nestin were positive;GFAP, OLIG-2, CD34, Bcl-2, CD163, CD31, CK20, CK7, ERG, FⅧ, GATA-3, HMB45 and Melan A were negative;Ki-67 proliferation index was 20%. Conclusion PIELMS is a rare primary intracranial mesenchymal tumor. It should be differentiated from subependymal giant cell tumor, ependymomas and epithelioid glioblastomas. The diagnosis should be combined with histopathological and immunohistochemical phenotype.