Shape and general appearance of pigmented skin tumors

For descripion of what we see with our naked eye on human skin and further more by looking through a dermatoscope there is a systematic analysis of the visual structures in human skin necessary to describe and to know what you see. Several systems for analysis patterns have been compiled by different authors, all of them focus on the degree of variation in four aspects of a skin mark:

Symmetry, border, color, and structures

The symmetry concerns the overall shape of an object. Two basic forms are considered to stand for a symmetric appearance: the outer shape having a round form or having an oval form. In a stricter sense a rectangular axis can be used to mirror a segment of the object - the skin mark - and from that judging the symmetry being either symmetric or asymmetric. The second aspect is the position of the point of deepest pigmentation being either in center or being out of center.

The outer border of a skin mark can be clear and well defined, can be dimming out in some areas, can be smooth, can be irregular.

The 5 Colors of the skin and of a lesions
Normal skin is yellowish light brown, in areas where pigment is lost, in regression areas, it is white. In skin tumors there are two shades light brown and dark brown. Then there is red for vessels, blue for deep laying pigment and black for dark superficial pigmentation

Pigment structures
There is a list of descriptive structures to be found in dermoscopy of benign and malignant pigmentcell tumors