中枢神经系统黑色素细胞瘤10例临床病理与超微结构分析

Clinicopathological and ultrastructural features of melanocytoma in central nervous system

目的探讨中枢神经系统(CNS)黑色素细胞瘤的临床病理特点、诊断与鉴别诊断及超微结构。方法对10例中枢神经系统黑色素细胞瘤的病理标本进行光镜、免疫组化及电镜观察并复习文献。结果 10例患者中女性6例,男性4例,年龄14～69岁,平均年龄37岁。6例患者随访4～60个月,均健在,其中4例复发,另4例失访。大体观察肿瘤呈结节状生长,多为单发,少数多发。组织学上肿瘤细胞为梭形或上皮样,束状排列,核圆形或卵圆形,异型不明显,少数复发病例瘤细胞有异型,伴有出血坏死和局部浸润。免疫组化示瘤细胞HMB45、S-100和vimentin(+),GFAP、EMA、NSE、Syn和Leu-7(-),Ki-67阳性细胞数<1%～2%。超微结构观察瘤细胞胞质内可见不同阶段的黑色素小体。结论中枢神经系统黑色素细胞瘤多为良性,切除彻底可治愈。容易与恶性黑色素细胞瘤以及伴有黑色素细胞分化的其他肿瘤混淆,其诊断依赖于组织学、免疫组化及超微结构观察。

Objective To investigate the clinical pathological characteristics, diagnosis and differential diagnosis of melanocytoma in central nervous system （CNS）. Methods Ten cases of melanocytoma were studied by light and electron microscopy and immunohistochemistry, and literatures were reviewed. Results 6 patients were female and 4 were male, aged 14-69 years （mean 37 years）. In this study, 6 cases were followed-up for 4-60 months, and no one was dead, but 4 cases reoccured. Tumors were nodular, most of which were single and few were multiple. Microscopically, the tumor consisted of spindle cells and epithelioicl cells arranged in bunchiness. The nuclei were oval and had no obvious abnormity. Recrudescent tumour was atypia, hemorrhage, necrosis and locally invasive. Immunohistochemical study showed vimentin, HMB-45 and S-100 were positive, and GFAP, EMA, NSE, Syn and Leu-7 were negative. Ki-67 positive cells were 〈 1% - 2% . Ultrastructural study showed many melanosomes of different stage in the cytoplasm. Conclusion Most of melancytomas in CNS are benign and can be cured by completely surgical removal. It may be confused with malignant melanoma, and other tumors with melanin differentiation. Diagnosis is based on histological characteristics supplemented with immunohistochemical and ultrastructural findings.