Ben-Izhak O, Lichtig C
Department of Pathology, Rambam Medical Center, Haifa, Israel.
Pathol Res Pract. 1993 Nov;189(9):1071-6; discussion 1077-83. doi: 10.1016/S0344-0338(11)80683-7.
Amelanotic malignant melanoma can present a diagnostic problem in histopathology, especially when it presents in an extracutaneous location. In such cases electron microscopy and/or immunohistochemistry are invaluable for diagnosis. A 63-year-old women with rectal bleeding was found to have an amelanotic malignant melanoma of the anal canal, with compatible clinical and gross pathology and light and electron microscopic findings. Tumor cells showed positive staining with antibodies to vimentin, S 100 protein, and HMB-45 (melanoma-specific antibody), but also with polyclonal antibody to carcinoembryonic antigen (CEA). Tumor cells failed to stain with monoclonal antibody to CEA. The nature and significance of CEA reactivity in malignant melanoma are discussed.
无色素性恶性黑色素瘤在组织病理学上可能会带来诊断难题，尤其是当其出现在皮肤外部位时。在这种情况下，电子显微镜检查和/或免疫组织化学对于诊断非常重要。一名63岁有直肠出血的女性被发现患有肛管无色素性恶性黑色素瘤，其临床、大体病理以及光镜和电镜检查结果均相符。肿瘤细胞对波形蛋白、S - 100蛋白和HMB - 45（黑色素瘤特异性抗体）抗体呈阳性染色，但对癌胚抗原（CEA）多克隆抗体也呈阳性染色。肿瘤细胞对CEA单克隆抗体不着色。本文讨论了恶性黑色素瘤中CEA反应性的性质和意义。
