Description: On the left, a brown lesion with by place an irregular (thick network), some grey dots, some blue-white structures, and an excentric skin-coloured structureless area. In this area, there is a polymorphic vascular pattern, with some dotted vessels and some short thin serpentine vessels. On the right, a mirror image of the left: a crescent shaped brown lesion. The network is also thickened by place, there are some grey dots (less than on the left), and a structureless skin-coloured area with monomorphic dotted vessels. No blue-white structures.

History: These are "twin cases" which show striking similarities: shape, color, structures. But one is "evil", the other gentle. In fact the left one is a malignant Melanoma (SSM, Clark III, Breslow 0.47 (no regression). The right one (courtesy of Dr Alan Cameron)is a dysplastic compound nevus with mild atypia.