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.
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: Marcial Álvarez-Salafranca; Mar García-García; Andrea Montes-Torres; Mariano Ara-Martín Journal: An Bras Dermatol Date: 2021-05-15 Impact factor: 1.896
Authors: Gabriella Fabbrocini; Maria Vastarella; Paola Nappa; Maria C Annunziata; Elisa Camela; Vincenzo Greco; Francesca Gaudiello; Maria Alessio; Luca Pierri; Andrea Catzola; Alfredo Guarino Journal: JAAD Case Rep Date: 2020-10-01