Illustration of the chaos and clues algorithm for the dermoscopic evaluation of pigmented skin lesions.
Chaos:
Asymmetric distribution of dermoscopic structures or colors
Clues for malignancy:
Eccentric, structureless area of any color, except skin color
Thick lines, reticular or branched
Gray or blue structures (ie, lines, circles, clods, and dots)
Black dots or clods, located along peripheral edge
Radial lines or pseudopods, segmental (or focal)
White lines, including lines arranged perpendicularly to each other (only seen with polarized dermoscopy) and reticular, white lines (seen with both polarized and nonpolarized dermoscopy)
Polymorphous vessels (more than one vessel morphology)
Lines parallel, ridges (volar) or chaotic (nails)
* Any exception to chaos? If yes, perform a biopsy.
Changing lesion in an adult
Lesion on the head or neck with gray appearance
Pigmented, nodular lesion
Acral lesion with parallel ridge pattern
Reproduced with permission from: Ashfaq A Marghoob, MD, and Natalia Jaimes, MD.
