ABSTRACT
Lesions on volar skin that manifest any of the melanoma-specifi c structures listed in Table 17.5 should be biopsied. With that said, most melanocytic lesions on volar skin will not display any of these structures. Instead, they will predominantly manifest a parallel pigment pattern with pigment visible in the furrows or ridges. The dermoscopic patterns suggestive of benignity in melanocytic tumors on volar skin (Green et al., 1998) include the parallel furrow pattern, lattice-like pattern, fi brillar or fi lamentous pattern, globular pattern, homogenous pattern, reticular pattern and globule-streak, and transition pattern (Saida et al., 2002; Saida et al., 2004; Miyazaki et al., 2005) (Fig. 8b.3). These patterns are described in further detail in the chapter 9a. In contrast to acral nevi, ALM on volar skin most often exhibits a parallel-ridge pattern and/or irregular diffuse pigmentation (Fig. 8b.3 and also Figs. 8b.4-8b.9). More advanced ALM tends to manifest a combination of colors and structures producing a multicomponent pattern (Fig. 8b.3 and also Figs. 8b.10, 8b.11). A word of caution is warranted here regarding the fi brillar pattern (Fig. 8b.12). The fi brillar pattern is created as a result of the shearing lateral pressure forces placed on the stratum corneum on the weight bearing portions of the sole. In nevi this pattern is created by fi ne transversely oriented lines in respect to the furrows and ridges. This pattern can also be seen in ALM on the sole but the lines making up the fi brillar pattern in ALM will be thicker, darker, gray, and more irregular. Because there are no shearing forces on the palms, the fi brillar pattern is almost nonexistent on this location and any lesion of the palm manifesting a fi brillar pattern should be viewed with suspicion. Lastly, it is important to be aware that a parallel ridge pattern can also be seen in benign conditions, such as in pigmented
Furrow = sulcus superficialis
Crista intermedia
Crista limitans
Eccrine Ductus Dermis
Stratum corneum
Epidermis
Ridge = crista superficialis
Eccrine openings
Figure 8b.1 Schematic representation of the anatomy of volar skin.
