Dots
Dots are small, round and well circumscribed structures smaller than globules (less than 0,1 mm, similar to the diameter of a terminal hair follicle) (Kittler et al., 2016a). Their color vary from brown, black, gray, blue to red. Histologically, they correspond to pigmentation along different levels of the epidermis or dermis. Black dots reveal pigmentation of the upper epidermis or the stratum corneum. Brown dots reveal small melanocytic nests in the epidermis or in the DEJ. Blue-gray dots correspond to the presence of pigment in the upper dermis or in dermal melanophages (the equivalent to peppering). In melanomas, dots are irregularly distributed and may be found focally at the periphery of lesions. Blue-gray dots can also correspond with small dermal aggregates of pigmented BCC. Red dots are equivalent to dotted vessels and can be seen in diverse cutaneous tumors such as keratinocyte carcinomas, Spitz nevi and melanomas (Massi et al., 2001b; Yadav et al., 1993). Black or brown dots may appear after acute ultraviolet exposure; however, these dots tend to disappear over time. It is interesting to note that many non–ultraviolet-induced dots that are successfully tape stripped off the skin reappear with time.
Gray-blue dots (also called granules or peppering) are due to fine melanin particles within melanophages or as extracellular “dust” in the superficial dermis; this feature is associated with regression.
Regular dots
Dots clustered at the center of the lesion, or located on the network lines (also called target network)
Irregular dots
Irregular dots tend to be heterogenous in size, shape and color and are frequently found at the periphery of a given lesion or scattered throughout the lesion.
In melanomas, dots are irregularly distributed and may be found focally at the periphery of lesions. Blue-gray dots can also correspond with small dermal aggregates of pigmented BCC. Red dots are equivalent to dotted vessels and can be seen in diverse cutaneous tumors such as keratinocyte carcinomas, Spitz nevi and melanomas [1].
