Acquired melanocytic lesions and the decision to excise: role of color variegation and distribution as assessed by dermoscopy.
BACKGROUND
Because melanoma may sometimes be difficult to differentiate from nevi with clinical atypia, many benign lesions also undergo surgical removal.


OBJECTIVE
To assess color type and distribution in dermoscopic melanocytic lesion images and to analyze the influence of color parameters on the diagnostic process and the decision to excise.


METHODS
Overall, 603 images, referring to 112 melanomas and 491 nevi, were retrospectively subdivided into four groups: "clearly benign," "follow-up," "dermoscopic atypical nevi," and "dermoscopic melanomas," according to their dermoscopic aspects. The frequency of color type, number, and asymmetry were evaluated on digital images.


RESULTS
With respect to lesions not eligible for excision according to dermoscopy (but excised for cosmetic reasons), those excised with a suspicion of malignancy showed a higher number of colors, whose distribution was also more asymmetric. Moreover, the frequency of the presence of black and blue-gray progressively increased from clearly benign lesions to atypical nevi and dermoscopic melanomas.


CONCLUSIONS
In dermoscopic images, color parameters are essential elements for the diagnosis of atypical nevus, which can be differentiated from both a clearly benign lesion and a melanoma. Furthermore, pigmentation asymmetry and the presence of blue-gray represent the main color features, which should lead to the decision to excise.
Seidenari
Stefania
S
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy. seidenari.stefania@unimo.it
Pellacani
Giovanni
G
Martella
Alessandro
A
D003661:Decision Support Techniques; D006801:Humans; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D008853:Microscopy / Q000379:methods*; D009508:Nevus, Pigmented / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*