title: Intraoperative dermoscopic features of onychomatricoma: a review of 10 cases.
abstract: BACKGROUND
  Amelanotic nail tumours are difficult to diagnose. Dermoscopy is an accessible tool successfully used in diagnosis of amelanotic or melanotic skin tumours. We have previously shown the usefulness of dermoscopy in the preoperative diagnosis of onychomatricoma (OM). In this study, we completed this work by identifying additional intraoperative criteria to better establish the initial diagnosis of this tumour.
  
  
  OBJECTIVE
  Evaluation of intraoperative dermoscopy in a small series of OM cases in order to define relevant diagnostic criteria.
  
  
  METHODS
  In total, 10 patients with OM diagnosed in our centre were enrolled in the study. Six trained dermoscopists individually evaluated each criterion, then the data were compared and a consensus reached after discussion between the observers. For each criterion, we analysed its frequency and its interobserver accordance. We defined three architectural criteria (the 'Sagrada Familia' sign, digitations and the 'mirror sign'), and three vascular criteria (sagittal vessels, dotted vessels and irregular vessels).
  
  
  RESULTS
  The Sagrada Familia sign, digitations and mirror sign were found in 100%, 90% and 70% of the cases, respectively, with high interobserver agreement. The vascular criteria were less regularly observed: sagittal, dotted and irregular vessels were respectively found in 80%, 70% and 50% of the OM cases, and were more difficult to assess, as shown by the lower interobserver agreement rates.
  
  
  CONCLUSIONS
  Intraoperative dermoscopy of the nail matrix and bed offers useful information for the diagnosis and management of OM. Larger comparative studies should be performed to evaluate the true benefit of this approach.
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.|Université Claude Bernard Lyon, Villeurbanne, France.
authors.forename: E
authors.initials: E
authors.lastname: Ginoux
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.|Université Claude Bernard Lyon, Villeurbanne, France.
authors.forename: M
authors.initials: M
authors.lastname: Perier Muzet
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.
authors.forename: N
authors.initials: N
authors.lastname: Poulalhon
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.
authors.forename: S
authors.initials: S
authors.lastname: Debarbieux
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.|Université Claude Bernard Lyon, Villeurbanne, France.|Cancer Research Center of Lyon, Lyon, France.
authors.forename: S
authors.initials: S
authors.lastname: Dalle
authors.affiliation: Department of Dermatology, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Lyon, France.|Université Claude Bernard Lyon, Villeurbanne, France.|Cancer Research Center of Lyon, Lyon, France.
authors.forename: L
authors.initials: L
authors.lastname: Thomas