title: Perilesional vs. lesional skin changes in senile lentigo.
abstract: BACKGROUND
  Senile lentigo (SL) is a common component of photoaged skin. It is characterized by hyperpigmented macules which affect chronically irradiated skin mostly after 50 years of age. This study was undertaken to assess the basic morphology of SL on dorsum of hands.
  
  
  METHODS
  A systematic comparison between lesional vs. perilesional skin using immunohistochemistry and electron microscopy was done to detect precursor lesions of SL and to determine whether melanocytes or keratinocytes were first affected in the evolution of lesions.
  
  
  RESULTS
  In 12 cases studied, the main findings show that clusters of perilesional keratinocytes accumulate melanin in large melanosomial complexes, and that melanocytes counts are increased respective to total length of section in lesional skin, but the increment is probably due to the development of characteristic epidermal rete ridges. Melanocytes had overall a normal ultrastructure, with mostly quiescent features in perilesional skin and melanosomial transport seeming more active in lesional skin.
  
  
  CONCLUSIONS
  Our data indicate that SL may represent a loss of epidermal melanin unit homeostasis due to chronic irradiation, where keratinocytic changes predominate over melanocytic changes. We hypothesize that abnormal pigment retention in keratinocytes is the primary defect in SL, which may partly explain the therapeutic effect of retinoids.
authors.affiliation: INSERM E217, University V. Segalen, Bordeaux, France. muriel.cario-andre@dematol.u-bordeaux2.fr
authors.forename: Muriel
authors.initials: M
authors.lastname: Cario-Andre
authors.forename: Sebastien
authors.initials: S
authors.lastname: Lepreux
authors.forename: Catherine
authors.initials: C
authors.lastname: Pain
authors.forename: Carine
authors.initials: C
authors.lastname: Nizard
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Noblesse
authors.forename: Alain
authors.initials: A
authors.lastname: Taïeb
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006225:Hand / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D007911:Lentigo / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008543:Melanins / Q000378:metabolism; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D020460:Melanosomes / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D012867:Skin / Q000378:metabolism / Q000473:pathology*
chemical_list: D008543:Melanins