We appreciate the insightful comments made by Drs Bauer and Garbe and welcome the additional analysis from the German population. They hypothesize that clinically inapparent nevic residua persist into the older population and that these remnants can serve as melanoma precursors. This is indeed an intriguing notion that deserves more attention. To use the maximum nevus counts in younger patients is to assume that a high percentage of moles persist into old age. Unfortunately, there are currently insufficient data to estimate the percentage of moles that undergo attrition (complete loss) vs attenuation (partial loss with nevic remnant). An appropriate analysis would involve the careful longitudinal monitoring of a cohort of nevi and the histological sampling of sites that had previously harbored moles. Our model is based on currently available data and is far from definitive. However, we believe that the question is important and deserves an initial attempt at an answer despite the inherently complex quantitative process.
Tsao H, Bevona C, Goggins W, Quinn T. Risk Estimation for Malignant Transformation of Melanocytic Nevi—Reply. Arch Dermatol. 2004;140(1):127. doi:10.1001/archderm.140.1.127-b