The association between large congenital melanocytic naevi and cutaneous melanoma: preliminary findings from an Internet-based registry of 379 patients.

There is ample evidence in the literature to support the fact that there is an increased risk of the development of melanoma in individuals with a large congenital melanocytic naevus (LCMN). The published melanoma risk estimates, by and large, do not distinguish between cutaneous and extracutaneous melanomas. It is currently not known to what extent each contributes to the overall cited melanoma risk estimates. In order to obtain a better understanding of the association between LCMN and cutaneous melanoma arising within an LCMN, we report the preliminary findings of a cross-sectional study of 379 patients, with a median age of 3 years, from the first self-referred, Internet-based registry of patients with LCMN. To date, no cutaneous melanoma has been reported; possible reasons for this finding are discussed. Further research is required to clarify the risk of the development of cutaneous melanoma separate from non-cutaneous melanoma and to identify subgroups of patients with LCMN at highest risk for the development of melanoma. This information will help to formulate appropriate decisions concerning the management of patients with LCMN.