第293课（中枢神经）病例探析（082）—巨细胞型胶质母细胞瘤

巨细胞型胶质母细胞瘤（giant cell glioblas-toma)为胶质母细胞瘤的一种少见亚型,发生率不足脑内肿瘤的1%及胶质母细胞瘤的5%,其临床及影像特点与经典的胶质母细胞瘤略有差别。该病变好发于中老年人,但比多形性胶质母细胞瘤发病年龄轻,约6%的病例发生于10岁以下,约9%的病例发生于20岁以下,约35%的病例发生于40岁以下,总平均发病年龄约42岁。男女发病之比为1:1.6。1913年首先由Meye等报道并命名。由于镜下观察含有丰富的网状纤维及血管分支,有学者曾认为巨细胞型胶质母细胞瘤是一种起源于大脑血管的间质肿瘤,并将其分为两型,一型是缺乏典型巨细胞的胶质母细胞瘤,另一型是由细胞直径>400um的典型巨细胞构成的肉瘤。而后来有学者依据在瘤体内见到类似星形细胞瘤或胶质母细胞瘤的成分,而把瘤体内多量的网状纤维认为是血管外膜细胞反应的产物,而不是肿瘤固有的结构。后来多数学者通过免疫组化的方法证实瘤细胞表达GFAP,提示其来源于星形细胞的本质。

Giant cell glioblas-toma, a rare subtype of glioblastoma, occurs in less than 1% of intracerebral tumors and 5% of glioblastomas. The disease is more common in middle-aged and elderly people, but it is younger than glioblastoma multiforme. About 6% of cases occur under the age of 10 years, about 9% occur under the age of 20 years, and about 35% occur under the age of 40 years. The total average age of onset is about 42 years. The incidence ratio of men and women was 1:1.6. It was first reported and named by Meye et al in 1913. Due to the microscopic observation contains rich reticular fibers and vascular branch, some scholars thought that giant cell glioblastoma is a originated in mesenchymal tumor of brain blood vessels, and it can be divided into two type, type 1 is the lack of a typical giant cell glioblastoma, another type is a typical giant cell by cell diameter > 400 um composed of sarcoma. Later, some scholars found ingredients similar to astrocytoma or glioblastoma in the tumor, and regarded the large amount of reticular fibers in the tumor as the product of the reaction of vascular outer membrane cells, rather than the inherent structure of the tumor. Later, most scholars confirmed GFAP expression in tumor cells by means of immunohistochemistry, suggesting that it originated from the nature of astrocytes.

发病部位常为颞叶和顶叶皮层下白质,其临床症状常以非特异性神经功能障碍为主,如头痛、恶心、呕吐、癫痫、性格改变及情绪异常等,病史通常较短,最严重的是颅内压增高症状,常由病变本身或脑水肿引起。其预后较经典胶质母细胞瘤更好,但如果肿瘤靠近脑室,易沿着脑脊液播散转移。病理上不同于一般的胶质瘤,光镜下可见巨大的瘤细胞、小圆形瘤细胞及梭形瘤细胞,非退变的异型瘤巨细胞>50%,直径>500um,伴其他形态的胶质瘤成分和间质成分。肿瘤细胞核大有核分裂,巨细胞核常为角状,含有明显的核仁,瘤内可见缺血性坏死,瘤内血管丰富,可见增生小血管,甚至出现肿瘤细胞环绕血管分布的假菊形结构。瘤细胞周围有丰富的网状纤维及常伴淋巴细胞浸润的特点。免疫组化染色GFAP标记物在巨细胞型胶质母细胞瘤中呈灶状分布,Ki67的表达为10%~30%, 核分裂像多见,细胞增殖活性较高,生长指数平均值为15%-20%。小的未分化的梭形细胞常增生活跃,CD34表达少见,CD34的表达量与肿瘤细胞分化呈正比。

Its clinical symptoms are mainly non-specific neurological disorders, such as headache, nausea, vomiting, epilepsy, personality changes and emotional abnormalities, etc. The medical history is usually short, and the most serious symptom is increased intracranial pressure, often caused by the lesion itself or cerebral edema. The prognosis of glioblastoma is better than that of classical glioblastoma, but if the tumor is near the ventricle, it is easy to spread and metastasize along the cerebrospinal fluid. Pathologically different from normal glioma, huge tumor cells, small round tumor cells and spindle tumor cells can be seen under the light microscope, non-degenerative xenomorphic giant cell >50%, diameter >500um, accompanied by other forms of glioma components and stromal components. The nucleus of the tumor has hyperkinesis, and the giant cell nucleus is often angular and contains obvious nucleoli. Ischemic necrosis can be seen in the tumor, blood vessels are abundant in the tumor, small proliferating blood vessels can be seen, and even pseudochrysanthemum structure of tumor cells distributed around blood vessels can be seen. The tumor cells are surrounded by abundant reticular fibers and are often associated with lymphocyte infiltration. Immunohistochemical staining of GFAP markers in giant cell glioblastoma showed focal distribution,Ki67 expression was 10%~30%, mitotic images were common, cell proliferation activity was high, the average growth index was 15%-20%. Small undifferentiated spindle cells often proliferate and are active, while CD34 expression is rare. CD34 expression is proportional to tumor cell differentiation.

巨细胞型胶质母细胞瘤发生于大脑半球表浅部位,以颞、顶叶皮层下多见。肿瘤境界清楚，通常与周围脑实质分界清晰。瘤体可通过白质纤维束累及对侧大脑半球,也曾有报道发生于脑室者。增强示肿瘤边界清楚,这可能与瘤体内含有较多的网状纤维有关。瘤体边界清楚及瘤周水肿较轻是巨细胞胶质母细胞瘤的一个显著影像学特点,可能与其瘤周侵袭性的典型高级别胶质瘤成分较少有关。

Giant cell glioblastoma occurs in the superficial part of the cerebral hemisphere, most commonly in the temporal and parietal cortex. The tumor is well circumscribed and usually well demarcated from the surrounding brain parenchyma. The tumor may involve the contralateral cerebral hemisphere through white matter fiber bundles, and it has been reported that the tumor occurred in the ventricle. Enhancement revealed a clear border of the tumor, which may be related to the fact that the tumor contained more reticular fibers. Clear tumor boundaries and mild peri-tumor edema are significant imaging features of giant cell glioblastoma, which may be related to the low composition of typical high-grade gliomas with peri-tumor invasion.

肿瘤瘤体内富含大量新生血管,增强示病变中央坏死区域不强化,周边实性组织环状强化。肿瘤细胞高度间变和不成熟性血管、新生血管结构不良、血栓形成等导致组织坏死,也可出现出血与囊变在CT上表现高密度出血及低密度囊变,MRI表现为长T1、长T2囊变信号,以及混杂出血信号。肿瘤也可呈囊实性混杂信号,T1WI呈低或混杂信号,T2WI呈高或混杂信号,强化明显,瘤周水肿轻微,与常见的典型高级别脑胶质瘤的指状水肿不同。该肿瘤多为单发,多发者少见,多发肿瘤的发病机制尚不明确,多数学者以多灶性脑胶质瘤来解释,即肿瘤沿脑白质纤维束或脑脊液播散形成。SWI可见新生的迂曲血管影。

The tumor contains a large number of new blood vessels, and the enhancement shows that the central necrotic area of the lesion is not strengthened, and the surrounding solid tissue is ringed with enhancement. Tumor cell height interchanges and immature blood vessels, poor neophyte structure, thrombosis and other causes of tissue necrosis, bleeding and cystic changes may also occur. On CT, high-density bleeding and low-density cystic changes are presented; on MRI, long-t1 and long-t2 cystic changes are presented, as well as mixed bleeding signals. Tumors may also present cystic and solid mixed signals, low or mixed signals on T1WI, high or mixed signals on T2WI, with obvious enhancement and slight peritumor edema, which is different from the typical high grade cerebral glioma. The pathogenesis of multiple tumors is still unclear. Most scholars have interpreted the multiple glioma as multiple focal gliomas, that is, tumors spread along the white matter fiber bundles or cerebrospinal fluid. SWI can see the newborn tortuous vascular shadow.

巨细胞型胶质母细胞瘤好发于中老年人,但比经典胶质母细胞瘤发病年龄更轻。肿瘤多为单发,发生于大脑半球表浅部位,以颞、顶叶皮层下多见。病史通常较短,瘤体边界清楚及瘤周水肿较轻是巨细胞胶质母细胞瘤的一个显著影像学特点。巨细胞型胶质母细胞瘤主要与以下疾病相鉴别

Giant cell glioblastoma usually occurs in middle-aged and elderly people, but at a younger age than classical glioblastoma. Most of the tumors occurred in the superficial part of the cerebral hemisphere, especially in the temporal and parietal cortex. The history is usually short, the tumor boundaries are clear, and peritumor edema is mild. Giant cell glioblastoma is mainly distinguished from the following diseases

1.多形性胶质母细胞瘤及间变性星形细胞瘤发病年龄偏大,病灶多位于脑白质内,较巨细胞型胶质母细胞瘤位置更深,MRI多表现为大范围的混杂信号肿块,坏死囊变及出血多见,瘤体边界不清,伴有中重度的水肿及占位效应,预后差。

Pleomorphic glioblastoma and anaplastic astrocytoma older, lesions in the brain white matter, a giant cell glioblastoma position deeper, more than MRI performance for a wide range of mixed signal lump, and hemorrhage, necrosis sac tumors boundary is not clear, with moderately severe edema and to take effect, prognosis is poor.

2.转移瘤绝大部分具有原发病灶,以灰白质交界处好发,病灶周围水肿明显,增强扫描呈均匀结节样或环状强化。

The majority of metastatic tumors have primary lesions, which tend to occur at the junction of gray and white matter, with obvious edema around the lesions, and uniform nodular or annular enhancement on enhanced scan.

3.脑膜瘤属脑外肿瘤,多与硬膜关系密切,以宽基底贴于脑膜,周围可见脑脊液环绕的脑外肿瘤征象,增强可见“脑膜尾征”,部分肿瘤可见邻近骨质的破坏。肿瘤坏死囊变较巨细胞型胶质母细胞瘤少.

Meningioma is an extrarebral tumor, most of which is closely related to the dura. The wide base is attached to the meninges, and there are signs of extrarebral tumors surrounded by cerebrospinal fluid around the meninges, and the 'meningeal tail sign' can be enhanced, and the destruction of adjacent bone can be seen in some tumors. Tumor necrotic cystic degeneration is less than giant cell glioblastoma