in cords or fascicles resembling neural structures in the dermis.3,7,8 Nevi in older people are also more likely to have fatty infiltration, mucin deposition, and fibrosis.9
TABLE 12.2.1 Comparison of Types of Dermal Nevi
defined when the vertical and horizontal axes are comparable, and the verrucous type consists of any combination of 3 previously discussed types.12 The surface of these nevi can be either smooth or coarsely papillated.14 Melanocytes are located primarily in the dermis, although junctional nests may exist. Melanocytes should mature and change from epithelioid to more lymphocyte-like as they descend deeper into the dermis. They can also become thinner, elongated, and schwannian in the deep dermis as well. There may be an accompanying terminal hair and/or large sebaceous glands.14
FIGURE 12.2.2 A close-up photograph of an Unna nevus. Note the presence of milia-like cysts and comedo-like openings on the surface of the nevus.