PMC3975198_01
a Clinical appearance of an asymptomatic blue-blackish plaque 2 mm in size on the left upper extremity. b Dermoscopy showed a homogeneous dark blue-black pigmentation at the center and peripheral blue-brownish streaks with branches (arrow) at the periphery. c The histopathologic specimen from the central lesion showed spindle cells with melanin pigments in the upper dermis, but not in the epidermis (hematoxylin and eosin stain, original magnification x100). d, e The histopathologic specimen from the peripheral lesion showed focally aggregated and isolated spindle cells with melanin pigments in the upper dermis [hematoxylin and eosin stain, original magnification, x100 (d), x400 (e)]. With the deep sections, we confirmed that the dermal dendritic melanocytes were distributed in the direction of the streaks.
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F1
A physical examination revealed an asymptomatic blue-blackish plaque 2 mm in size on the left upper extremity (fig. 1a). Dermoscopy showed a central homogeneous dark blue-black pigmentation and peripheral blue-brownish streaks with branches (arrow) (fig. 1b). The specimen from the central lesion showed spindle cells with melanin pigments in the upper dermis, but not in the epidermis (fig. 1c). A deep section of the peripheral lesion identified focally aggregated and isolated spindle cells with melanin pigments in the upper dermis (fig. 1d, e).