We thank Drs Saurat and Braun for their comments. They point out that in their study they found modifications in 69\% of benign melanocytic skin lesions, which is a much higher frequency than in our study.1,2 Our study focused on enlargement as the main modification and we found a frequency of enlargement of 5.3%. This number does not include structural or color modifications. However, we reported that the frequency of modifications other than enlargement that included structural and color changes was 31.2%, which is about half the frequency as reported by Braun and al.2 This difference may be explained by differences in the design of the studies. In contrast to our study, which was a prospective cohort study, that by Braun and al may be influenced by selection bias in that lesions that were expected to change over time were preferably included, which may explain the high number of Spitz nevi. Although our study included 1612 nevi, no lesion was finally diagnosed as a Spitz nevus. In contrast, the study by Braun et al included 113 lesions of which 13 were Spitz nevi. This is a much higher frequency as expected to occur by chance alone.
Binder M, Kittler H. Changes Even in Benign Melanocytic Nevi. Arch Dermatol. 2001;137(2):228-229. doi: