Fig. 19

Effect of sectioning orientation on the histopathologic features of acral nevus. These two figures show histopathologic features of the same acral nevus on the sole. (a) In the tissue section cut perpendicularly to the surface skin markings, most melanocytes are arranged in nests mainly located at the dermo-epidermal junction, indicating that this is a benign acral nevus. (b) In contrast, in the tissue section cut parallel to the skin markings, many melanocytes are seen as solitary units within the epidermis, simulating the histopathologic features of acral melanoma in situ