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Leukoderma induced by rhododendrol is different from leukoderma of vitiligo in pathogenesis: A novel comparative morphological study
Author(s) -
Tsutsumi Reiko,
Sugita Kazunari,
Abe Yuko,
Hozumi Yutaka,
Suzuki Tamio,
Yamada Nanako,
Yoshida Yuichi,
Yamamoto Osamu
Publication year - 2019
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/cup.13396
Subject(s) - vitiligo , melanosome , pathogenesis , pathology , histopathology , melanin , melanocyte , dermis , immunohistochemistry , tyrosinase , biology , dermatology , medicine , melanoma , cancer research , biochemistry , genetics , enzyme
Background Rhododendrol (rhododenol), an inhibitor of tyrosinase activity, is used as a skin‐whitening component. Many cases of leukoderma after the application have been reported, termed rhododenol‐induced leukoderma (RIL). The aim of this study was to clarify the pathogenesis of RIL morphologically through comparison with vitiligo. Methods We examined 14 cases of RIL and 15 cases of vitiligo using routine histopathology and immunohistochemistry. Thirteen cases of RIL, six cases of vitiligo and specimens of the RIL mouse model were evaluated by electron microscopy. Results There were common findings in RIL and vitiligo at the light‐microscopic level: (a) vacuolar changes in the dermo‐epidermal junction, (b) melanophages in the papillary dermis, (c) perifollicular lymphocyte infiltration, (d) loss or decrease of basal melanin pigment and (e) decrease of melanocytes in the lesions. The ultrastructural observations showed specific findings of RIL: (a) remaining melanocytes in depigmented lesions, (b) inhomogeneous melanization in melanocytes and (c) degenerated melanosomes in melanocytes. Some of the findings were observed in a RIL mouse model. Furthermore, it is notable that cell organelles of melanocytes were intact in our RIL cases. Conclusion Morphological changes of RIL targeting melanosomes in melanocytes without degeneration of organelles reflect the reversible clinical course of most cases.