目的：探讨中枢神经系统黑色素细胞瘤的临床病理特征。方法：对1例发生于脊髓的黑色素细胞瘤的临床表现、组织形态、免疫组织化学等进行分析，并复习相关文献。结果：患者女性，52岁，右侧肢体活动不灵活9个月。MRI示颈3、4椎体水平见一软圆形界限清楚肿块，大小约3.7 cm × 0.8 cm × 1.3 cm。镜检示肿瘤细胞排列呈巢团状、漩涡状及束状；瘤细胞呈软圆形或梭形，部分细胞呈上皮样，大部分细胞质内见多量黑色素颗粒；瘤细胞无明显异型，无核分裂像。免疫组织化学Vimentin、HMB45、S-100、Melan-A均为阳性，Ki67指数5%~10%；其余Ckpan、EMA、GFAP、CD34、SMA、Desmin和P53均为阴性。结论：黑色素细胞瘤是一种罕见的低度恶性中间型肿瘤，临床上易与弥漫性黑色素细胞增多症和黑色素瘤病、恶性黑色素瘤以及伴有黑色素分化的其他肿瘤混淆。其诊断主要靠病理形态学特征、免疫组化、影像学及电镜检查有助于诊断与鉴别诊断。治疗主要依靠肿块切除，必要时可局部放疗，术后随访非常重要。
Melanocytoma of central nervous system: a clinicopathological analysis
Objective: To investigate the clinicopathological features of melanocytoma of central nervous system. Methods: The clinical manifestations, histopathological and immunohistochemical results were analyzed in one case of melanocytoma occurring in the spinal cord with reviewing the related literatures. Results: The patient was a 52-year-old woman presenting a not flexible right limb for 9 months. MRI showed that an abnormal round well-circumscribed mass was observed on vertebral 3-4 level, measured 3.7 cm × 0.8 cm × 1.3 cm. Microscopically, the tumor consisted of round, oval or spindle cells, formed tight nests with a superficial resemblance, arranged in bunchiness or whorls. Heavily pigmented tumor cells and tumoral macrophages were seen at the periphery of nests. Melanocytoma cells showed oval or spindled nuclei with small nucleoli and clear to eosinophilic cytoplasm with variable fine pigment. Cytologic atypia and mitoses were absent. Immunohistochemical study showed that Vimentin, HMB45, S-100, Melan-A were positive, Ki67 proliferation index was 5%~10% , other antibodies including Ckpan, EMA, GFAP, CD34, SMA, Desmin and P53 were all negative. Conclusion: Melanocytoma is a rare tumor of intermediate malignant potential, which is difficult to be distinguished from diffuse melanocytosis and melanomatosis, malignant melanoma, and other tumors with melanin differentiation. Definitive diagnosis requires histological examination, supplemented with immunohistochemistry, radiological characterization and ultrastructural findings. The complete resection of the lump with post-operative follow-up, as well as local radiotherapy, is the main modality of treatment.