title: Dermoscopic clues to differentiate facial lentigo maligna from pigmented actinic keratosis.
abstract: BACKGROUND
  Dermoscopy is limited in differentiating accurately between pigmented lentigo maligna (LM) and pigmented actinic keratosis (PAK). This might be related to the fact that most studies have focused on pigmented criteria only, without considering additional recognizable features.
  
  
  OBJECTIVE
  To investigate the diagnostic accuracy of established dermoscopic criteria for pigmented LM and PAK, but including in the evaluation features previously associated with nonpigmented facial actinic keratosis.
  
  
  METHODS
  Retrospectively enrolled cases of histopathologically diagnosed LM, PAK and solar lentigo/early seborrhoeic keratosis (SL/SK) were dermoscopically evaluated for the presence of predefined criteria. Univariate and multivariate regression analyses were performed and receiver operating characteristic curves were used.
  
  
  RESULTS
  The study sample consisted of 70 LMs, 56 PAKs and 18 SL/SKs. In a multivariate analysis, the most potent predictors of LM were grey rhomboids (sixfold increased probability of LM), nonevident follicles (fourfold) and intense pigmentation (twofold). In contrast, white circles, scales and red colour were significantly correlated with PAK, posing a 14-fold, eightfold and fourfold probability for PAK, respectively. The absence of evident follicles also represented a frequent LM criterion, characterizing 71% of LMs.
  
  
  CONCLUSIONS
  White and evident follicles, scales and red colour represent significant diagnostic clues for PAK. Conversely, intense pigmentation and grey rhomboidal lines appear highly suggestive of LM.
authors.affiliation: Skin Cancer Unit, Arcispedale Santa Maria Nuova IRCCS, Viale Risorgimento 80, 42100, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Lallas
authors.affiliation: Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Tschandl
authors.affiliation: Skin Cancer Unit, Arcispedale Santa Maria Nuova IRCCS, Viale Risorgimento 80, 42100, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Kyrgidis
authors.affiliation: Department of Dermatology, Allergology and Environmental Medicine II, Hospital Thalkirchner Straße, Städtisches Klinikum Munich, Munich, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Stolz
authors.affiliation: Skin and Cancer Associates, Plantation, FL, U.S.A.
authors.forename: H
authors.initials: H
authors.lastname: Rabinovitz
authors.affiliation: School of Medicine, University of Queensland, Brisbane, Qld, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Cameron
authors.affiliation: Dermatology Practice, Nemours, France.
authors.forename: J Y
authors.initials: JY
authors.lastname: Gourhant
authors.affiliation: Skin Spectrum Medical Services, Como, WA, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Giacomel
authors.affiliation: Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Kittler
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, Qld, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Muir
authors.affiliation: Dermatology Unit, Second University of Naples, Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Argenziano
authors.affiliation: Department of Dermatology and Venerology, Non-Melanoma Skin Cancer Unit, Medical University of Graz, Graz, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Hofmann-Wellenhof
authors.affiliation: Department of Dermatology and Venerology, Non-Melanoma Skin Cancer Unit, Medical University of Graz, Graz, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Zalaudek
mesh_terms: D000368:Aged; D046169:Dermoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D005153:Facial Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D018327:Hutchinson's Melanotic Freckle / Q000000981:diagnostic imaging* / Q000473:pathology; D055623:Keratosis, Actinic / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D015588:Observer Variation; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology