颅内转移性恶性黑色素瘤:一例报告并文献复习

Multiple intracranial malignant melanoma metastasis:report of one case with review of literature

目的探讨颅内转移性恶性黑色素瘤临床组织病理学及免疫组织化学特征。方法应用组织病理学及免疫组织化学检测方法对1例颅内多发转移性恶性黑色素瘤患者的两次手术标本进行观察,通过复习文献分析其组织病理学和免疫组织化学特征,提出诊断与鉴别诊断要点。结果男性患者,48岁。因颅内多发占位性病变、肿瘤卒中而行右侧额颞叶肿瘤切除术。两次手术标本组织病理学表现不一:首次右侧额叶病灶表现为异型性上皮样肿瘤细胞围绕毛细血管和纤维组织呈乳头状排列;再次手术标本为右侧颞叶,病灶表现为梭形细胞呈片巢状或束状排列,胞质丰富、淡染或透亮,胞核异型性明显、核仁呈明显嗜酸性。左侧腹股沟淋巴结活检提示肿瘤转移,且肿瘤组织局部可见大量黑色素颗粒。免疫组织化学染色肿瘤细胞弥漫表达S-100蛋白、人黑色素细胞瘤抗原45、Melan-A和波形蛋白,部分表达上皮膜抗原,而细胞角蛋白、高分子角蛋白、低分子角蛋白、胶质纤维酸性蛋白、突触素、神经微丝蛋白等表达阴性。结论颅内转移性恶性黑色素瘤的组织学表现复杂多样,临床病史和影像学资料对诊断具有重要参考价值,但明确诊断仍需依靠免疫组织化学检测结果。需注意与转移癌、脑膜肿瘤、淋巴瘤及其他含黑色素的颅内肿瘤相鉴别。

Objective To explore the clinicopathological and immunohistochemical features of intraeranial malignant melanoma metastasis. Methods Analysed the clinical features, bistopathologic findings and immunohistochemical staining in 2 lesions of one case with multiple intraeranial malignant melanoma metastasis, and studied the diagnosis and differentiation of this disease with literature review. Results The pathologic findings of the 2 lesions located in the right frontal lobe and right temporal lobe were dissimilar to each other. The previous lesion presented as old hematoma was composed of a few papilliform structures within sheet of bleeding with capillaries and fibrous tissue surrounded by epithefioid cells. The following lesion in the right temporal lobe was predominantly composed of spindle cells with rich cytoplasm, marked nuclear atypia and eosinophile nucleoli that arranged in cell nests and fascicles. Brisk mitotic activity and necrosis could also be seen in the tumor. Left inguinal lymph nodes metastasis notable with thick melan in granule inside and outside the tumor cells was found, and the tumor cells were similar to those of the lesion in the right temporal lobe. Immunohistochemistry with antibodies for S-100 protein （S- 100）, HMB45, Melan- A, vimentin （Vim）, epithelial membrane antigen （EMA）, cytokeratin （CK）, glial fibrillary acidic protein （GFAP）, synaptophysin （Syn） and neurofilament protein （NF） was performed. A diffuse reactivity of the neoplastic cells for S-100 protein, HMB45, Melan-A, vimentin was observed. EMA presented partially positive. All other markers were negative. Conclusion The histopathologic findings of intracranial malignant melanoma metastasis are quite complicated. Although the clinical case history and neuroimaging are important, the diagnosis of the disease is dependent on immunobistochemieal staining method. It must be differentiated from metastatic carcinomas, meningeal tumors, malignant lymphomas and other melanocytic neoplasms.