title: Rosettes and other white shiny structures in polarized dermoscopy: histological correlate and optical explanation.
abstract: BACKGROUND
  Rosettes are a specific form of a white shiny structure seen with polarized dermoscopy. The precise morphological correlate and optical explication are not known.
  
  
  OBJECTIVE
  To estimate the frequency of rosettes in ex vivo dermoscopy and to find explication and morphologic correlate of this dermoscopic feature.
  
  
  METHODS
  A series of 6108 consecutive skin biopsies were examined with ex vivo dermoscopy and when rosettes were present serial transverse sections with polarization were examined.
  
  
  RESULTS
  In this series of 6108 consecutive skin biopsies, rosettes were found on ex vivo dermoscopy in 63 cases. When multiple we observed that they are always oriented at the same angle. Transverse sections with polarization of these lesions proved that smaller rosettes are mainly caused by polarizing horny material in adnexal openings, and larger rosettes by concentric perifollicular fibrosis.
  
  
  CONCLUSIONS
  Rosettes are an optical effect of crossed polarization by concentric fibrosis or horny material and hence are not lesion-specific.
authors: Dermpat, Ardooie, Belgium.
authors: M
authors: M
authors: Haspeslagh
authors: Dermpat, Ardooie, Belgium.
authors: M
authors: M
authors: Noë
authors: Dermpat, Ardooie, Belgium.
authors: I
authors: I
authors: De Wispelaere
authors: Dermpat, Ardooie, Belgium.
authors: N
authors: N
authors: Degryse
authors: Dermatology, Maldegem, Belgium.
authors: K
authors: K
authors: Vossaert
authors: Dermatology, Maldegem, Belgium.
authors: S
authors: S
authors: Lanssens
authors: Pathology, Spedali Civili, Brescia, Italy.
authors: F
authors: F
authors: Facchetti
authors: Pathology, UZ Antwerp, Antwerp, Belgium.
authors: K
authors: K
authors: Van Den Bossche
authors: Dermatology, UZ, Gent, Belgium.
authors: L
authors: L
authors: Brochez
mesh_terms: D001706:Biopsy / Q000379:methods; D046169:Dermoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D006801:Humans; D015203:Reproducibility of Results; D012867:Skin / Q000473:pathology*; D012871:Skin Diseases / Q000175:diagnosis*