Tronnier M, Wolff H H
Department of Dermatology, Medical University of Lübeck, Germany.
Am J Dermatopathol. 1995 Feb;17(1):1-6. doi: 10.1097/00000372-199502000-00001.
A causative role of UV light in the development of melanocytic neoplasms has often been suggested. In order to investigate the short-term effects of UV light on melanocytic nevi, the morphological and immunohistochemical changes in nevi after a single UV irradiation are studied in 12 nevi from 10 patients and compared with the nonirradiated part of the same nevus. After irradiation more melanocytes above the dermal-epidermal junction are observed in seven nevi, simulating a melanoma in situ in three nevi. Moreover, a marked increase in the expression of HMB-45 is found after irradiation in all investigated nevi, indicating an activation of the melanocytes and active melanosome formation. The metabolic activity correlates with the ultrastructural findings, which show a large cytoplasm, hypertrophic Golgi apparatus, abundant mitochondria, and an increased number of melanosomes of different stages. One week after irradiation, no increase in the proliferative activity of the melanocytes is found. The morphological and immunohistochemical changes after one low dose of UV irradiation should be considered in the differential diagnosis of pigmented skin lesions. The UV-irradiated nevus should be added to the list of so-called simulators of malignant melanoma.
紫外线在黑素细胞肿瘤发生过程中的致病作用常被提及。为了研究紫外线对黑素细胞痣的短期影响，对10例患者的12个痣进行单次紫外线照射后，研究其形态学和免疫组化变化，并与同一痣的未照射部分进行比较。照射后，在7个痣中观察到真皮 - 表皮交界处上方有更多黑素细胞，3个痣呈现原位黑素瘤样表现。此外，在所有研究的痣中，照射后HMB - 45表达显著增加，表明黑素细胞活化及活跃的黑素小体形成。代谢活性与超微结构结果相关，超微结构显示细胞质大、高尔基体肥大、线粒体丰富以及不同阶段黑素小体数量增加。照射一周后，未发现黑素细胞增殖活性增加。在色素性皮肤病变的鉴别诊断中应考虑低剂量紫外线照射后的形态学和免疫组化变化。紫外线照射的痣应被列入所谓恶性黑素瘤模拟物清单。
