title: Dermoscopy and reflectance confocal microscopy of pigmented actinic keratoses: a morphological study.
abstract: BACKGROUND
  Actinic keratoses (AKs) are very common lesions on sun damaged skin and, when pigmented, represent a challenge in the differential diagnosis with early melanoma. Non-invasive diagnostic methods, such as dermoscopy and reflectance confocal microscopy (RCM) have been shown to improve the diagnostic accuracy of melanoma and non-melanoma skin cancer, however, only one case report described confocal findings of pigmented AKs up to now.
  
  
  OBJECTIVE
  The aim of our retrospective morphological study was to analyse dermoscopic and confocal images of a series of histopathologically proven pigmented AKs, located on the face and other body sites, to define peculiar features of these "difficult to diagnose" lesions.
  
  
  METHODS
  Clinical, dermoscopic and RCM images of 17 histopathologically confirmed pigmented AKs were retrospectively collected from the databases of four skin lesion clinics in Italy and USA. Dermoscopic and RCM images were analysed for prevalent morphological features.
  
  
  RESULTS
  The majority of the lesions were located on the face (n = 8); followed by scalp (n = 4) and trunk (n = 4); and one lesion was located on the lower limbs. On dermoscopy the majority of lesions were characterized by grey dots/globules/granularity and structureless brown pigmentation. The main RCM feature of pigmented AKs was as follows: (i) the presence of epidermal changes (atypical keratinocytes, parakeratosis, scaling); (ii) increased epidermal thickness; (iii) bright, small, dermal papillae with enlarged interpapillary space; and (iv) intraepidermal dendritic cells referrable to Langherans cells. Features suggestive of melanocytic lesions, such as nesting, meshwork pattern or atypical cells infiltrating the junction, were never detected in our case series at the dermal epidermal junction (DEJ) level.
  
  
  CONCLUSIONS
  Larger case series with adequate control population are warranted to validate these findings and to test their value in clinical setting.
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale s.maria Nuova, IRCCS, Reggio Emilia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Moscarella
authors.affiliation: Skin and Cancer Associates, Plantation, FL, USA.
authors.forename: H
authors.initials: H
authors.lastname: Rabinovitz
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Zalaudek
authors.affiliation: Pathology Unit, Arcispedale S.Maria Nuova, IRCCS, Reggio Emilia, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Piana
authors.affiliation: Skin Cancer Unit, IRCCS IRST Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (FC), Italy.
authors.forename: I
authors.initials: I
authors.lastname: Stanganelli
authors.affiliation: Skin and Cancer Associates, Plantation, FL, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Oliviero
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale s.maria Nuova, IRCCS, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Lallas
authors.affiliation: Department of Dermatology, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Ardigo
authors.affiliation: Oncologic Dermatology, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cota
authors.affiliation: Oncologic Dermatology, San Gallicano Dermatologic Institute, IRCCS, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Catricalà
authors.affiliation: Skin Cancer Unit, IRCCS IRST Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori, Meldola (FC), Italy.
authors.forename: L
authors.initials: L
authors.lastname: Mazzoni
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pellacani
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale s.maria Nuova, IRCCS, Reggio Emilia, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Argenziano
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale s.maria Nuova, IRCCS, Reggio Emilia, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Longo
mesh_terms: D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000175:diagnosis / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D012189:Retrospective Studies
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