Ribé Adriana, McNutt N Scott
Department of Pathology, New York Presbyterian Hospital-Cornell University Weill Medical College, New York, New York, USA.
Am J Dermatopathol. 2003 Apr;25(2):93-9. doi: 10.1097/00000372-200304000-00001.
Lentigo maligna (LM), a type of malignant melanoma in situ, and pigmented actinic keratosis (PAK) may have similar clinical appearances but are different in prognosis and treatment. Diagnosis is established by skin biopsy. In certain cases, microscopic features may be very similar in both entities, making it difficult to determine whether the pigmented atypical cells are keratinocytes or melanocytes. Immunohistochemical markers can be useful for the identification of melanocytes in these cases. There are limitations to the use of some standard immunohistochemistry markers, however. S100 proteins are a varied group of proteins that are of special interest because of their dysregulated expression in neoplastic disorders. Their expression is changed during malignant transformation, progression, and/or metastasis in various cell lines and tumors, including melanomas. Our study analyzed the expression of several of the S100 protein subtypes (S100A2, S100A6, and S100A8/A9 or A12) in 38 LM cases and 44 PAK cases to define their potential value in the distinction between these entities together with their role in the development of early malignant melanoma of the skin. The results showed an upregulation of S100A2 protein in atypical keratinocytes in PAK and in normal keratinocytes adjacent to melanoma cells in LM. There was also an upregulation of S100A8/A9 or A12 protein, as detected by the antibody MAC387, in normal keratinocytes adjacent to both atypical keratinocytes and melanocytes in PAK and LM, respectively. There were statistically significant differences in the level of positive cells and in the pattern of immunoreactivity for anti-S100A2 and MAC387 in each entity, however. Moreover, the findings of our study support the notion that melanocyte-keratinocyte interactions are abnormal in both of these disease entities and may be involved in their progression.
恶性雀斑样痣（LM）是一种原位恶性黑色素瘤，与色素性光化性角化病（PAK）可能具有相似的临床表现，但预后和治疗方法不同。通过皮肤活检进行诊断。在某些情况下，两者的微观特征可能非常相似，难以确定色素性非典型细胞是角质形成细胞还是黑素细胞。免疫组织化学标志物在这些病例中有助于黑素细胞的识别。然而，一些标准免疫组织化学标志物的使用存在局限性。S100蛋白是一组多样的蛋白质，因其在肿瘤性疾病中表达失调而备受关注。它们的表达在各种细胞系和肿瘤（包括黑色素瘤）的恶性转化、进展和/或转移过程中发生变化。我们的研究分析了38例LM病例和44例PAK病例中几种S100蛋白亚型（S100A2、S100A6和S100A8/A9或A12）的表达，以确定它们在区分这些实体中的潜在价值以及在皮肤早期恶性黑色素瘤发生中的作用。结果显示，PAK中非典型角质形成细胞以及LM中黑素瘤细胞相邻的正常角质形成细胞中S100A2蛋白上调。通过抗体MAC387检测，PAK和LM中分别与非典型角质形成细胞和黑素细胞相邻的正常角质形成细胞中S100A8/A9或A12蛋白也上调。然而，每个实体中抗S100A2和MAC387的阳性细胞水平和免疫反应模式存在统计学显著差异。此外，我们的研究结果支持这样一种观点，即这两种疾病实体中黑素细胞与角质形成细胞的相互作用均异常，且可能参与其进展。
