Melan-A无助于发生于光损害皮损的原位黑色素瘤与色素光化性角化病的鉴别  

Melan-A:Not a helpfulmarker in distinction between melanoma in situ on sun-damaged skin and pigmented actinic keratosis

作　　者：El Shabrawi-Caelen L. Kerl H. Cerroni L. 牛新武 

机构地区：[1]Department of Dermatology, University of Graz, Auenbruggerplatz 8, 8036 Graz, Austria Dr.

出　　处：《世界核心医学期刊文摘（皮肤病学分册）》2005年第1期25-26,共2页Digest of the World Core Medical JOurnals:Dermatology

摘　　要：Pigmented actinic keratosis is one of the simulators of early melanoma in situ from severely sun-damaged skin. Close scrutiny of the hematoxylin and eosin stained section does not always allow an unequivocal diagnosis, because it is sometimes difficult to distinguish pigmented keratinocytes from melanocytes. Immunohistochemical stains, such as S-100 and HMB-45, are used routinely to address this problem. Melan-A, also known as MART-1, is an additional melanocytic marker and has proved to be useful in identifying metastatic tumors of melanocytic origin. The usefulness of this marker to discriminate pigmented actinic keratosis from early melanoma in situ, however, has not yet been a subject of investigation. In this study we evaluatedMelan-A expression in ten unequivocal cases of pigmented actinic keratosis and compared the staining pattern with that of S-100, HMB-45, and tyrosinase. In all ten cases the number of cells highlighted with Melan-A was by far larger than those labeled with S-100, HMB-45, and tyrosinase. Four cases showed clusters of Melan-A positive cells being suggestive of melanocytic nests. Even areas of normal skin adjacent to the actinic keratosis featured prominent staining of Melan-A, but only inconsistent labeling of intraepidermal melanocytes with S-100, HMB-45, and tyrosinase. We therefore believe that Melan-A is a more sensitive marker for intraepidermal melanocytes than S-100, HMB-45, and tyrosinase. In addition there may be expression of Melan-A in keratinocytes and nonmelanocytic cells. To avoid an erroneous diagnosis of malignant melanoma one should therefore interpret results ob-tained fromMelan-A stained slides carefully and in the context with other melanocytic markers.Pigmented actinic keratosis is one of the simulators of early melanoma in situ from severely sun-damaged skin. Close scrutiny of the hematoxylin and eosin stained section does not always allow an unequivocal diagnosis, because it is sometimes difficult to distinguish pigmented keratinocytes from melanocytes. Immunohistochemical stains, such as S-100 and HMB-45, are used routinely to address this problem. Melan-A, also known as MART-1, is an additional melanocytic marker and has proved to be useful in identifying metastatic tumors of melanocytic origin. The usefulness of this marker to discriminate pigmented actinic keratosis from early melanoma in situ, however, has not yet been a subject of investigation. In this study we evaluatedMelan-A expression in ten unequivocal cases of pigmented actinic keratosis and compared the staining pattern with that of S-100, HMB-45, and tyrosinase. In all ten cases the number of cells highlighted with Melan-A was by far larger than those labeled with S-100, HMB-45, and tyrosinase. Four cases showed clusters of Melan-A positive cells being suggestive of melanocytic nests. Even areas of normal skin adjacent to the actinic keratosis featured prominent staining of Melan-A, but only inconsistent labeling of intraepidermal melanocytes with S-100, HMB-45, and tyrosinase. We therefore believe that Melan-A is a more sensitive marker for intraepidermal melanocytes than S-100, HMB-45, and tyrosinase. In addition there may be expression of Melan-A in keratinocytes and nonmelanocytic cells. To avoid an erroneous diagnosis of malignant melanoma one should therefore interpret results ob-tained fromMelan-A stained slides carefully and in the context with other melanocytic markers.

关 键 词：黑色素瘤 MELAN-A 光化性角化病 黑素 转移性肿瘤 酪氨酸酶 角质形成细胞 细胞标志物 免疫组化染色 阳性细胞 

分 类 号：R739.5[医药卫生—肿瘤]