JAMES M.GRICHNIKMD, PhD
The lesions are from the back of a 43-year-old woman (Figure 1), the left leg of a 52-year-old man (Figure 2), and the back of a 55-year-old man (Figure 3) (size bar, 5 mm). All 3 lesions reveal a similar pattern, a central network with white lines and brown holes. This feature has been called the central white network and is usually surrounded by a discrete pigment network. It is characteristic of some large dermatofibromas. The central white network is a variation of the classic central white scarlike patch in that the histopathologic correlation is similar. However, this dermoscopic feature appears particularly interesting in light of the differential diagnosis from other pigmented lesions. Histopathologically, it corresponds with a special distribution of the central fibrosis of dermatofibromas. This feature should be differentiated from a dermoscopic feature called negative pigment network or inverse of the pigment network that is observed in many Spitz nevi and some invasive melanomas. Dermoscopically, this negative pigment network consists of light areas (not white) making up the grids of the network and dark areas filling the holes. Histopathologically, it represents elongated hypomelanotic rete ridges and large nests of pigmented cells located at the dermal papillae instead of fibrosis (characteristic of central white network in dermatofibromas).
Zaballos P, Puig S, Malvehy J. Dermoscopy of Atypical DermatofibromaCentral White Network. Arch Dermatol. 2006;142(1):126. doi:10.1001/archderm.142.1.126