Dermoscopy

Dermoscopy helps to differentiate melanomas from benign naevi and from mimickers such as pigmented basal cell carcinoma, seborrhoeic keratoses or haemorrhages under the skin. A dermascope renders the stratum corneum translucent to allow for the examination of the subsurface morphological details of the skin. Reticular pattern consists of pigmented ‘lines’ and hypopigmented ‘holes’ forming a honeycomb pattern. Found in dermal naevi, a cobblestone pattern is similar to a globular pattern but consists of large aggregates of globules or dermal nests of melanocytes arranged in a square or angulated shape that resembles cobblestones. Dots and globules may occur in both benign naevi and melanomas. Two types of streak patterns can be seen: radial streaming and pseudopods. Melanomas with neovascularization may result in atypical vascular patterns with dotted, glomerular or bizarre vessels.