Pigmentation refers to a dark-brown to gray-black, diffuse area that precludes recognition of more subtle dermoscopic features such as pigment network or vascular structures. Evidently, pigmentation is the dermoscopic criterion that may reveal most variations on the theme as reflected by the many synonyms used for pigmentation, namely, irregular extension, blotches and black lamella. In this atlas we grouped pigmentation in a somewhat systematic approach as follows: localized regular, localized irregular, diffuse regular and diffuse irregular pigmentation.
The histopathologic correlates of the various forms of pigmentation correspond to otherwise dissimilar histopathologic structures that share pronounced melanin pigmentation throughout the different layers of the epidermis and/or upper dermis.
Because of the variability of the many faces of pigmentation its diagnostic significance is limited. Localized regular as well as diffuse regular pigmentations are suggestive of benignancy, whereas localized irregular and diffuse irregular pigmentations favor malignancy.