The study in the ARCHIVES by Kittler et al1 of common melanocytic nevi using digital epiluminescence microscopy was illuminating. Circumferential enlargement was frequently identified in common nevi of children, though rarely in adults, over a period of almost 1 year.1 This adds to what we know from previous studies about the natural history of common acquired nevi. Benign acquired nevi progress from lentigo simplex, to flat pigmented junctional nevi, to elevated pigmented compound nevi, to more elevated skin-colored intradermal nevi over decades.2,3 When intradermal nevi from hundreds of patients were examined, the intradermal depth measurement (the distance between the dermoepidermal junction and the top of the underlying intradermal nevus) increases with age.4 In other words, intradermal nevi continue to elevate as collagen is laid down over nests of nevus cells in the upper dermis. Therefore, moles slowly evolve and change during the entire life of any individual.
Brodell RT. Enlarging Common Melanocytic Nevi and the Diagnosis of Malignant Melanoma. Arch Dermatol. 2001;137(2):227. doi: