[The dysplastic nevus. An Ariadne's thread through a conceptual labyrinth].

The concept of the dysplastic nevus is flawed by inconsistencies regarding the clinical presentation, histological features and biological considerations. With regard to basic mechanisms of malignancy, dysplastic nevi exhibit neither increased proliferation indices nor elevated telomerase activity. These traits denote a benign lesion that is highly prevalent among Caucasians. In rare cases, the distinction from malignant melanoma may pose problems.