J Shin1, J-Y Park1, S J Kim1, H Y Kang1. 1. Department of Dermatology, Ajou University School of Medicine, Suwon, Korea.
Abstract
BACKGROUND: Flattened rete ridges occurring on the face are not uncommon in solar lentigo (SL). AIM: To investigate the morphological changes of keratinocytes in facial SL with flattened rete ridges and melasma. METHODS: In total, 25 patients with facial SL showing flattened rete ridges and 20 patients with melasma, in which rete ridge flattening is also a common feature, were included in the study. Skin biopsies were performed on lesional skin and perilesional normal skin. RESULTS: The histological findings showed that the epidermis was significantly thicker in SL skin with flattened rete ridges compared with perilesional normal skin. Comparative quantitative analysis of epidermal morphology revealed that the individual keratinocytes were larger in size in lesional skin, without a significant change in the number of cells. Anti-p16 antibody staining was more intense in lesional epidermis, suggesting senescence of keratinocytes in the thickened epidermis. By contrast, melasma samples showed no significant difference in epidermal thickness or keratinocyte morphology in terms of number or size compared with normal skin. CONCLUSIONS: These findings suggest that senescent changes in keratinocytes are important in the development of SL, even in the absence of rete ridge elongation, and the removal of keratinocytes harbouring melanin could be a possible strategy for SL treatment.
BACKGROUND: Flattened rete ridges occurring on the face are not uncommon in solar lentigo (SL). AIM: To investigate the morphological changes of keratinocytes in facial SL with flattened rete ridges and melasma. METHODS: In total, 25 patients with facial SL showing flattened rete ridges and 20 patients with melasma, in which rete ridge flattening is also a common feature, were included in the study. Skin biopsies were performed on lesional skin and perilesional normal skin. RESULTS: The histological findings showed that the epidermis was significantly thicker in SL skin with flattened rete ridges compared with perilesional normal skin. Comparative quantitative analysis of epidermal morphology revealed that the individual keratinocytes were larger in size in lesional skin, without a significant change in the number of cells. Anti-p16 antibody staining was more intense in lesional epidermis, suggesting senescence of keratinocytes in the thickened epidermis. By contrast, melasma samples showed no significant difference in epidermal thickness or keratinocyte morphology in terms of number or size compared with normal skin. CONCLUSIONS: These findings suggest that senescent changes in keratinocytes are important in the development of SL, even in the absence of rete ridge elongation, and the removal of keratinocytes harbouring melanin could be a possible strategy for SL treatment.
Authors: Stefan Hacker; Rainer Mittermayr; Stefanie Nickl; Thomas Haider; Diana Lebherz-Eichinger; Lucian Beer; Andreas Mitterbauer; Harald Leiss; Matthias Zimmermann; Thomas Schweiger; Claudia Keibl; Helmut Hofbauer; Christian Gabriel; Mariann Pavone-Gyöngyösi; Heinz Redl; Erwin Tschachler; Michael Mildner; Hendrik Jan Ankersmit Journal: Sci Rep Date: 2016-04-29 Impact factor: 4.379