李 彬         陈晓亮       西永明　    赵 鹏

Primary melanocytoma in the spinal canal of the cervical spine was rare to see in the central nervous system (CNS). Benign forms with better prognosis were even rarer. We described a 22-year-old male with a history of pain in the nape of the neck and numbness in the left limb and normal voluntary control of excretory functions. Under radiologic investigations, there was an intradural mass measuring 2.0cm×1.0cm. The lesion was surgically excised. Histopathologic examination revealed heavily melanin-pigmented cells with similar nuclei. Obvious nucleoli existed without mitotic figures. A probable diagnosis of meningeal melanocytoma was made. The diagnosis was confirmed by the results of immunohistochemical analysis, showing the strongly positive expression of HMB-45 in the tumor cells. Vimentin and S-100 were also diffusely positive, while epithelial membrane antigen was distinctly negative.