[Dysplastic nevi] or [atypical nevi] are acquired nevi that are >5 mm in diameter and have irregular or variegate pigmentation (blues, browns, black, red, or white) with poorly defined or [irregular border lesions].
[irregular blue pigmentation][irregular brown pigmentation][irregular black pigmentation][irregular red pigmentation]
[irregular white pigmentation]
Some of these lesions may be precursors for melanomas. Patients with atypical nevi who have two or more first-degree relatives with [dysplastic nevi] and a [history of melanoma] have nearly a 100% chance of developing melanomas. Follow these patients carefully for any signs of change in their nevi. These changes can best be assessed when baseline high-quality photographs have been taken so that the current findings can be compared with previous images.
Melanomas are skin cancers arising from the malignant transformation of melanocytes. As discussed, they may arise from precursor lesions such as atypical nevi, [congenital nevi], and LM. They may also arise de novo from melanocytes within the skin. Suspect melanoma if a [pigmented lesion] displays any combination of asymmetry, border irregularity, variegate colors, or a diameter >5 mm [asymmetry lesion][border irregularity lesion][variegate color lesion][lesion diameter more than 5 mm]. Other worrisome signs are [lesion pruritus], [ulceration], [lesion bleeding], or [change in lesion color] or [change in size of the lesion].