Abstract

The understanding of dysplastic (also known as atypical) nevi as a precursor lesion of malignant melanoma is hampered by incongruities on different levels. Neither epidemiological data nor clinical and histomorphological features nor biological aspects are suitable to prove a sequential tumor progression from nevi to melanoma. With respect to basic mechanisms of malignant transformation such as proliferation rate and telomerase activity, no significant differences between dysplastic and other nevi could be found. Thus, the dysplastic nevus represents a type of benign nevi and is to be distinguished from early forms of malignant melanoma in diagnostics. Their use as an easy to take "emergency exits" for pathologists must come to an end.