Microscopic examination of 2 skin biopsy specimens showed a discrete collection of epithelioid cells in the papillary dermis abutting the epidermis in both specimens (Figure 4). The cells had variable nucleus-cytoplasm ratios, with prominent nucleoli and abundant pigment lying in the cytoplasm and in macrophages. Occasional mitoses were noted. Some sections showed similar cells in clusters in vessel lumina (Figure 5). The inflammatory infiltrate was minimal, consisting of a few lymphocytes admixed among the tumor cells. Epidermotropism was not present in either specimen.
Pigmented Papules and Weight Loss. Arch Dermatol. 1998;134(7):861-866. doi: