Chromosomal changes in dysplastic nevi

The dysplastic nevus is considered to be a precursor lesion of melanoma, re presenting one of the first steps in the progressive transformation from no rmal melanocyte to melanoma. Various risk degrees of developing cutaneous m elanoma in patients with dysplastic nevi have been advanced, based on the p resence of dysplastic nevi or melanoma or both in members of the patient's family. We report on the cytogenetic study of three nevi in a young patient with a family history of melanoma. Each nevus showed a simple clonal chrom osome change. The t(6;15)(q13;q21) translocation found in one of them seems of particular significance in view of the fact that a similar one, with br eakpoint at 6q13 was reported both in an acquired nevus from a patient with a family history of melanoma and in a case of cutaneous metastatic melanom a. These observations seem to support the hypothesis of the existence of a biological continuum between normal melanocyte and melanoma. Furthermore, t he finding of chromosome changes similar to those associated with melanoma reinforces the need for a careful follow-up of patients with dysplastic nev i. (C) Elsevier Science Inc., 1999. All rights reserved.