恶性脑膜瘤7例临床病理学分析

Malignant meningiomas:a clinicopathological analysis of 7 cases

目的探讨恶性脑膜瘤的临床病理学特点及诊断要点。方法收集7例恶性脑膜瘤病例进行临床资料、影像学、病理形态学及免疫组化分析,并结合文献探讨其诊断及鉴别诊断。结果 7例患者中男性3例,女性4例,年龄20～78岁,平均年龄55.9岁。患者因抽搐、头痛、肌力减退、视力丧失等就诊。肿瘤位于大脑镰旁、额颞部、前颅凹及鞍上斜坡等。头颅MRI示病变不均匀异常信号及等信号影,增强扫描后病变出现明显强化。其中横纹肌样脑膜瘤2例,镜下见中等偏大、偏位核及胞质红染的横纹肌样细胞;乳头状脑膜瘤1例,镜下见具有纤维血管轴心的乳头状及血管周围假菊形团结构;间变型脑膜瘤4例,镜下见排列密集、明显异型、核分裂象多见的癌样细胞。免疫组化:肿瘤细胞EMA和vimentin(+),CD34、GFAP和CK均(-);其中3例PR(+),Ki-67阳性指数为14%～57%。结论恶性脑膜瘤(WHOⅢ级)较为少见,可分为横纹肌样、乳头状、间变型3个组织学亚型,具有高复发和高侵袭性生长特点,需与黑色素瘤、非典型畸胎样瘤/横纹肌样瘤、胶质细胞来源肿瘤、转移癌等鉴别。

Objective To explore the clinicopathological features and diagnosis of maligant meningiomas. Methods Seven cases of malignant meningiomas from the General Hospital of Beijing Military Region were studied with analysis of clinical data, MRI, pathological and immunohistochemical features, and the diagnosis and differential diagnosis were discussed with review of the literature. Results There were 3 males and 4 females with age ranging from 20 to 78 years （ mean 55.9）. Tumors were located in the side of cerebral falx, front and temple, anterior cranial fossa, saddle and clivus area. The clinical manifestations were tic, headache, decrescence of muscle strength and visual loss. Head MRI showed lesions with abnormal or inequable signal and obvious enhancement after contrast scan. Microscopic examination showed rhabdoid cells with middle or slight larger size, unsymmetric nuclei and red cytoplasm in 2 cases of rhabdoid meningiomas. Papillary structures with fibriovascular axis and pseudo- cauliflowering cells surrounding vessels were observed in 1 case of papillary meningioma. Cancer-like cells with high density, obvious atypia and more mitotic figures were observed in 4 cases of anaplastic meningiomas. Immunohistochemical staining showed that tumor cells were positive for EMA and vimentin in all cases and for PR in 3 cases, but negtive for PR, CD34, GFAP and CK in all cases. The Ki-67 positive cells were ranged from 14% to 57%. Conclusions Malignant meningioma is composed of rhabdoid meningioma, rhabdoid meningioma and anaplastic meningioma, which has high recurrence rate and aggressive behaviors. It is necessary to differentiate it from melanoma, atypical teratoid/rhabdoid tumor, glioma and metastatic carcinoma.