PMC4868937_01
a A 47 x 26 mm slightly elevated light brown plaque on the back of the patient's head. A 16 x 13 mm erosive lesion and an 18 x 17 mm dome-shaped black node were recognized in this plaque lesion. The left dotted line indicates the histopathological sections shown in fig. 2a-c, the center dotted line indicates the sections shown in fig. 2d-i, and the right dotted line indicates the sections shown in fig. 2j-l. b Dermoscopic features of the dome-shaped black node showing black homogenous areas, surface scales and arborizing vessels. c Dermoscopic features of the erosive lesion showing glomerular vessels in pink homogenous areas.
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F1
A 16 x 13 mm erosive lesion and an 18 x 17 mm dome-shaped black node were recognized in that plaque (fig. 1a). Dermoscopic analysis of the dome-shaped black node showed black homogenous areas, surface scales and arborizing vessels (fig. 1b). Dermoscopic analysis of the erosive lesion showed glomerular vessels in pink homogenous areas (fig. 1c).
a Histopathological findings from the black node showing tumor nests with a sheet-like appearance extending downward into the deep dermis and melanin deposits scattered irregularly (HE stain; original magnification, x20). b Each tumor cell was atypical and insular tumor aggregations were recognized in the tumor nests (HE stain; original magnification, x200). c Immunohistochemistry for Ber-EP4 (original magnification, x400). d Histopathological findings at the periphery of the black node showing tumor nests composed of several different components. The dotted box indicates the portion shown in e (HE stain; original magnification, x12.5). e In the upper portion, tumor nests with interlacing cords were noted (HE stain; original magnification, x100). f Numerous structures resembling follicular germinative cells were recognized and some of those structures extruded from interlacing cords (HE stain; original magnification, x200). g In the lower portion, the tumor nests exhibited lobular aggregations and had ductal and/or cystic structures (HE stain; original magnification, x100). h Tumor nests consisting of sebocytes with a foamy cytoplasm (HE stain; original magnification, x400). i Immunohistochemistry for adipophilin (original magnification, x400). j In the erosive lesion, papillated structures with apocrine epithelium were observed (HE stain; original magnification, x20). k The epithelium of tubules displayed decapitation secretion and numerous plasma cells were noted in the stroma (HE stain; original magnification, x100). l In the slightly elevated light brown plaque, the epidermis was hyperkeratotic and enlargement of sebaceous lobules was noted (HE stain; original magnification, x40).
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F2
Melanin deposition was scattered irregularly and bleeding was also observed within the tumor nests (fig. 2a). Insular tumor aggregations were recognized in the tumor nests and some of those aggregations contained melanin deposits (fig. 2b). Immunohistochemistry showed a positive reaction for Ber-EP4 in those tumor nests (fig. 2c). At the periphery of the black node, tumor nests also extended into the deep dermis and were composed of several different components (fig. 2d). Some of those tumor nests exhibited cribriform and reticular patterns (fig. 2e). Numerous structures resembling follicular germinative cells were recognized and some of those structures extruded from interlacing cords (fig. 2f). In the lower portion, tumor nests exhibited lobular aggregations, and had ductal and/or cystic structures (fig. 2g). The tumor nests consisted of sebocytes, which had a foamy cytoplasm (fig. 2h). Immunohistochemistry showed a positive reaction for adipophilin in those tumor nests (fig. 2i). Tubules lined by apocrine epithelium had an anastomosing pattern (fig. 2j). The epithelium of the tubules was lined by 2-3 layers displaying apocrine secretion of decapitation secretion and numerous plasma cells were noted in the stroma of the papillated structures (fig. 2k). Enlargement of sebaceous lobules connecting with abnormal follicular infundibula was noted (fig. 2l).