Melanoma arising from pre-existing naevus in carriers of a germline CDKN2A pathogenic variant

In this study we used total body photography (TBP) to determine whether melanoma emerges from a preexisting naevi or normal-appearing skin in individuals with pathogenic CDKN2a variant. In total, 60 melanoma cases occurred in 44 CDKN2a germline carriers. In addition, we observed that 78% of the 60 included melanoma cases developed from preexisting naevi, significantly higher than the 30% reported for sporadic melanoma. This high incidence may be due to the numerous atypical naevi and early bi-allelic loss of CDKN2A. Our findings underscore the importance of routine TBP in these patients for early detection of melanoma. More than previously appreciated, the surgical removal of melanocytic naevi in these high-risk patients may prevent melanoma development.