Dermoscopy features of melanoma incognito: Indications for biopsy

Background: To avoid missing melanoma, the current practice is to biopsy all suggestive skin lesions. Although most cases of melanoma exhibit clinical clues leading to the correct diagnosis, melanoma can mimic benign lesions. Dermoscopy has been shown to increase the diagnostic accuracy of clinically equivocal lesions, but little is known about its ability to detect melanoma in the context of lesions that appear clinically benign. Methods: We present 7 difficult-to-diagnose melanomas, in which additional clues provided by dermoscopy increased the index of suggestion and led us to perform a biopsy. Results: Our cases highlight the following 7 management rules: 1) Dermoscopy should not be used only for suggestive skin lesions. 2) Biopsy lesions missing clinicodermoscopic correlation. 3) Biopsy lesions with unspecific pigment pattern. 4) Biopsy lesions with spitzoid features. 5) Biopsy lesions with extensive regression features. 6) In patients with multiple nevi, biopsy lesions changing after short-term follow-up. 7) Biopsy pink lesions with an atypical vascular pattern. Limitations: The reported series of cases is small. Dermoscopy has not been rigorously compared with handheld magnification (as with a X7 loupe). Conclusions: Dermoscopy can increase the index of suggestion to perform biopsy in difficult-to-diagnose melanomas.