Reflectance confocal microscopy accurately discriminates between benign and malignant melanocytic lesions exhibiting a ‘dermoscopic island’


  • Conflict of interest
    None. All authors declare that they have sufficiently participated in the submitted work to deserve authorship, all have had access to clinical material and have revised the manuscript before submission. Corresponding author (Dr Sébastien Debarbieux) endorses the scientific responsibility of the reported work herein.

  • Funding sources
    This work is supported in part by grants from Lyon 1 University (to LT), the Hospices Civils de Lyon (to LT) and the ligue contre le cancer du Rhone (to LT). Administrative, technical or material support: L Thomas. Study supervision: S Debarbieux and L Thomas.

  • Statistical analysis
    Not applicable.

  • Ethical committee approval: waived (see underneath)
    This study has not been registered in a public trial registry because it does not ‘prospectively assigns human subjects to intervention or comparison groups to evaluate the cause and effect relationship between a medical intervention and a health outcome’.

S. Debarbieux.


Background  The ‘dermoscopic island’ is a term that was recently proposed to design an area of a pigmented lesion with a uniform dermoscopic pattern different from the remainder of the lesion. The positive predictive value of this sign for the diagnosis of melanoma is about 50%.

Objective  The purpose of our study was to see if reflectance confocal microscopy (RCM) permitted to accurately distinguish between nevi and melanoma in such lesions.

Methods  Five lesions of five consecutive unselected patients, with a dermoscopic island but no feasible clear cut diagnosis on the basis of dermoscopy alone were examined by RCM before excision for histopathological evaluation.

Results  Two lesions corresponded to nevi, and three lesions were early melanomas arising on a benign naevus in one case, and on a dysplastic naevus in two cases. In all five cases, RCM permitted to make the correct diagnosis, with a very good correlation with conventional histopathology.

Conclusion  Reflectance confocal microscopy appears as a promising tool not only to enhance the early diagnosis of melanoma but also to avoid unnecessary excisions of lesions with a dermoscopic island.