색소성 피부질환에 대한 큐스위치 알렉산드라이트 레이저 치료직후의 조직, 면역조직화학, 전자현미경적 소견.

Abstract

Background : There have been only a few electron microscopic studies after laser treatment of pigmented skin lesions. Objective : The purpose was to investigate the pathologic, immunohistochemical, and electron microscopic changes following Q-switched alexandrite laser treatment of pigmented skin lesions. Methods : Three patients with acquired bilateral nevus of Ota-like macules, and 2 patients with cafe´au lait macule were irradiated with Q-switched alexandrite laser. Forty biopsies were taken before and immediately after laser treatment. Hematoxylin-eosin, Fontana-Masson, and gp100 staining were performed for the evaluation of the histopathologic and immunohistochemical findings of the specimens. Electron microscopic findings were also evaluated. Results : Histopathologically, suprabasilar separations were observed immediately after laser treatment. Vacuolar alterations of pigment-containing cells were frequently found in the epidermis and/or in the dermis. Fontana-Masson and gp100 staining positivity changed to negative or decreased in the epidermis immediately after laser treatment, while they changed to negative in the dermis. Ultrastructurally, epidermal pigment-containing cells frequently showed severe vacuolar changes in the cytoplasm, pyknotic nuclei, and vacuolated and/or fragmented melanosomes immediately after laser treatment. Dermal melanocytes frequently revealed vacuolated and/or fragmented melanosomes immediately after laser treatment. Conclusion : Histopathologic, immunohistochemical, and electron microscopic examination of pigmented skin lesions immediately after Q-switched alexandrite laser treatment demonstrated vacuolated or fragmented melanosomes and vacuolar alteration of pigment-containing cells in the epidermis and/or in the dermis, which suggested selective photothermolysis of melanosomes.