As Dr Whitmore notes, for any individual pigmented lesion on the skin, the final diagnosis can only be made after biopsy of the lesion. Clinically diagnosed dysplastic nevi span a continuum from minimally abnormal nevi that barely fulfill criteria for diagnosis of dysplastic nevi to markedly abnormal nevi that cannot clinically be distinguished from early melanoma and need to be biopsied to rule out either in situ or invasive melanoma. At either end of the spectrum, the clinical diagnosis is difficult. In selecting the photographs, we chose representative samples of all of the types of nevi (in the middle of the spectrum clinically).
Patients with florid dysplastic nevi may have many, sometimes hundreds, of abnormal-appearing nevi. At the time of initial examination, of course, any lesion that is suspicious for melanoma should be removed. Removal of all unusual-appearing nevi is not recommended, however, because (1) the chance of any 1
Tucker MA, Hartge P, Halpern A, Elder DE, Guerry D, Clark WH, Holly EA, Sagebiel RW. Differentiating Dysplastic Nevi From Melanoma-Reply. JAMA. 1997;278(7):548-549. doi:10.1001/jama.1997.03550070040031