Abstract
A diagnosis of early melanoma is difficult, as such a lesion often mimics nevus or solar lentigo. 93% of melanoma would occur de novo. It is important to know acquired nevi, namely Clark′s nevus (flat or slightly elevated), Miescher′s nevus (hemispherical, mostly on the face), Unna′s nevus (verrucous, mostly on the scalp and neck) and Reed/Spitz′s nevus (occurring in the childhood) to diagnose melanoma correctly. Congenital and blue nevi are usually easy to diagnose. Must think of melanoma if it is atypical as a nevus. Seborrheic keratosis, basal cell carcinoma and vascular lesions are sometimes clinically indistinguishable from melanoma, however it might be easy on dermoscopy. The two step procedure is helpful on dermoscopic diagnosis. The first step is differentiation between melanocytic and non–melanocytic lesion based upon criteria, and the second step is differentiation between benign melanocytic lesions and melanoma on irregularity of distribution in the colour and structures.
