Ultrastructural Study of Vitiligo

ABSTRACT

BACKGROUND: There is a long-standing controversy whether melanocytes in vitiligo of more than 1 year duration are actually lost or still present. Resolving this matter is essential in understanding the underlying pathology and for the development of the treatment. On previous immunohistochemical and ultrastructural studies of vitiligo lesions, damage of melanocyte and keratinocyte in early lesions were reported and complete absence of melanocyte in long standing lesions were known. OBJECTIVE: This study aimed to determine the existence of the differences in pathologic changes in melanocytes according to the duration of the lesion. METHODS: We investigated the vitiliginous skin samples from 31 patients with early(less than 1 year duration) vitiligo and 30 patients with long standing(l to 5 years duration) vitiligo under the electron microscopy. RESULTS: Multiple degenerative changes in melanocytes were observed in the early and long standing lesions. In long standing lesions, degeneration of melanocytes including pyknotic, in-dented nuclei, vacuolated cytoplasms and blunted dendrites were more pronounced than early lesions. Even in long standing lesions, definite or presumptive melanocytes were observed in 16(53.3%) of 30 cases. CONCLUSION: Our results suggest that the melanocytes of vitiligo lesions were damaged and that the percentage of degenerative changes increase in accordance with the duration of the lesion. However, in long standing lesions as well as in early lesions, some residual melanocytes can be observed ultrastructurally.