小脑常见肿瘤的生物学特性与MRI鉴别诊断

目的:探讨小脑星形细胞瘤、髓母细胞瘤和血管母 细胞瘤的生物学特性与MRI特点.方法:收集术前行MRI检 查并经手术病理证实的51例小脑肿瘤.结合临床表现,观察 其发生部位、信号、结构和病理.结果:星形细胞瘤<15岁10 例(10/2);髓母细胞瘤<15岁9例,16～27岁7例;血管母细 胞瘤<15岁4例(4/19).67%的星形细胞瘤好发于小脑半 球;69%的髓母细胞瘤位于蚓部;血管母细胞瘤66%见于中线 半球旁;92%星形细胞瘤为囊性或囊实性.髓母细胞瘤儿童 多起自四脑室顶部髓帆生殖中心的胚胎残余细胞(8/2),成人 多源于小脑软膜下原始的外颗粒层细胞,以实性为主.血管母 细胞瘤源于原始血管形成中残余的胚胎细胞,70%为大囊小 结节;星形细胞瘤多为长T1,T2信号.髓母细胞瘤为混杂稍 长T1,T2信号,增强呈中度强化.血管母细胞瘤,增强时壁结 节明显强化.结论:小脑星形细胞瘤好发于半球,儿童多

Biological features of common cerebellar tumors and MRI differential diagnosis

AIM: To discuss the biological features of astrocytoma, medulloblastoma and hemangioblastoma as well as their MRI characteristics. METHODS: The location, shape, signals, anatomical structures, histopathological presentations and clinical manifestations were analyzed in 51 cases with cerebellar tumors, who had had pre-surgery MRI and whose tumor had later been surgically confirmed. RESULTS: In the subjects under the age of 15 years old, 10 had astrocytoma (10/2) and 67% of which occurred in the cerebellar hemisphere; 9 had medulloblastoma (7 other subjects in age 16 to 27) and 69% of which occurred in the vermis; 4 had hemangioblastoma (4/19) and 66% of which occurred by the cerebellar midline. 92% of the astrocytoma was cystous or cystous-consolidated. Medulloblastoma originated from the remaining embryo cells of the reproductive center on top of the fourth ventricle in children (8/2) and from cells in the external granular layer beneath the cerebellar pia mater on the cerebellar surface in adults. Hemangioblastoma originated from the remaining and disrupted embryo cells during the original blood vessel formation in the early embryo and 70 % of which was macro-cyst with micro-nodules. Astrocytoma presented long T 1 and T 2 MRI signals, medulloblastoma presented mixed longer T 1 and T 2 MRI signals with medium intensification, and hemangioblastoma presented significant wall nodule intensifying effects. CONCLUSION: Astrocytoma mostly occurs in children, in the cerebellar hemisphere with cystous or cystous-consolidated presentation. Medulloblastoma occurs mostly in young adults, in the vermis with consolidated presentation. Hemangioblastoma occurs mostly in adults, by the cerebellar midline with significant wall nodule intensifying effects.