Novel morphological study of solar lentigines by immunohistochemical and electron microscopic evaluation

Solar lentigines (SL) are hyperpigmented lesions generally seen in elderly people. Their pathogenesis has not been completely elucidated. We examined 75 cases of SL using routine histopathology and immunohistochemistry. In addition, seven cases were evaluated by electron microscopy. Histopathologica...

Full description

Saved in:
Bibliographic Details
Published in:Journal of dermatology 2013-07, Vol.40 (7), p.528-532
Main Authors: Watanabe, Tessin, Tahira, Makoto, Morino, Shinichi, Horie, Takashi, Adachi, Koji, Tsutsumi, Reiko, Yamada, Nanako, Yoshida, Yuich, Yamamoto, Osamu
Format: Article
Language:English
Subjects:
Adult
Aged
Aged, 80 and over
CD163
electron microscopy
Female
Humans
Immunohistochemistry
Keratins - metabolism
Lentigo - etiology
Lentigo - metabolism
Lentigo - pathology
Male
Microscopy, Electron, Transmission
Middle Aged
poorly immunostimulatory macrophage
Skin - ultrastructure
solar lentigines
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Solar lentigines (SL) are hyperpigmented lesions generally seen in elderly people. Their pathogenesis has not been completely elucidated. We examined 75 cases of SL using routine histopathology and immunohistochemistry. In addition, seven cases were evaluated by electron microscopy. Histopathologically, we observed vacuolar changes in the dermoepidermal junction in 85% of the cases. Dermal melanophages were seen in 77% of the cases. The immunohistochemical expression rates in the epidermis for cytokeratin (CK)15, CK14, CK10, p63 and nestin were 76%, 100%, 100%, 100% and 17%, respectively. In 58 cases showing dermal melanophages, expression rates of CD163 and factor XIIIa on melanophages were 79% and 83%, respectively. Double positivity for both proteins was identified in 44 cases (75%). Ultrastructurally, vacuolar structures were seen in the cytoplasm of basal cells and upper dermis in all cases examined. We observed elimination processes of damaged basal keratinocytes, which were probably produced by ultraviolet (UV) irradiation, into the papillary dermis. The segregated damaged cell bodies containing melanin granules seemed to be phagocytosed by poorly immunostimulatory macrophages labeled immunohistochemically by CD163 and factor X IIIa, contributing to prolonged pigmentation of SL. In addition, repeated basal keratinocyte damages may be in association with altered CK and p63 expression patterns in the constituent cells of SL.
ISSN:0385-2407
1346-8138
DOI:10.1111/1346-8138.12165