JAMES M.GRICHNIKMD, PhD
The lesions shown are from the shoulder of a 52-year-old white woman (Figure 1), the leg of a 34-year-old white woman (Figure 2), and the thigh of a 38-year-old white woman (Figure 3) (size bar, 2.5 mm). All 3 lesions reveal similar findings. White patchy areas in the center of the lesions, confluent or multiple, and peripheral pigment network are present in some lesions (Figure 1 and Figure 2), absent in others (Figure 3). This pigmented network corresponds to hyperplastic epidermis with hyperpigmentation of the basal layer and elongated rete ridges, whereas the whitish patch structure is caused by the presence of a clear (Grenz) zone from the spindle cell tumor in the dermis, and is composed of fibroblastlike spindle cells, histiocytes, and blood vessels in varying proportions. Capillaries may be plentiful in the stroma, giving a special appearance (Figure 3).
Puig S, Romero D, Zaballos P, Malvehy J. Dermoscopy of Dermatofibroma. Arch Dermatol. 2005;141(1):122. doi:10.1001/archderm.141.1.122