The Elongated Dermatofibroma: A New Dermoscopic Variant?

The most common features of dermatofibromas seen in polarized and nonpolarized dermoscopy are central white scarlike patches, brown globulelike structures, vascular structures, and a peripheral fine pigmented network.² Kilinc Karaarslan et al³ described atypical dermatofibromas with linear irregular crypts, which were seen in 26.9% of all studied cases. These irregular crypts were mainly medium in size (10 lesions), with only 2 lesions being tiny and regularly distributed. Only one lesion had atypical clinical and dermoscopic features occurring as an atrophic plaque with multiple small scarlike areas and peripherally distributed pigment network.³ Based on this typology, we believe our patient represents a case of elongated dermatofibroma that could be an atrophic variant of dermatofibroma. This form would not appear as a small scarlike area with pigment network in a somewhat patchy distribution³ but as a scarlike linear chord with a bipolar pigment network. Zaballos et al¹ described 10 dermoscopic patterns of dermatofibroma (N=412); the most common was a central white patch and peripheral pigment network in approximately 35% of cases. A white scarlike patch was observed in 57.0% of dermat-ofibromas in 4 variants: (1) a solitary structure located in the center; (2) multiple white scarlike patches; (3) white scarlike patch extending throughout the lesion or irregularly distributed; and (4) white network (central, total, or irregular).¹ Agero et al² first described the new feature as a central white patch characterized by shiny white streaks. The most frequent dermoscopic pattern associated with dermatofibromas is the central white scarlike patch and peripheral delicate pigment network.^1,4 Arpaia et al⁴ observed that dermoscopic patterns may correspond to distinct sequential stages of the formation of dermatofibroma. The linear character we described may be related to a variant of scarring keloid dermatofibroma.⁵