PMC4772936_01
A 5-mm orange-pink papule on the right frontal scalp.
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F1
A 12-year-old girl presented with a 1-year history of a slow-growing papule on her right frontal scalp (fig. 1).
Low power reveals numerous nests and fascicles of cells intersecting the collagen bundles of the superficial and deep reticular dermis. HE. x4.
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F2
Histopathologic examination revealed a diffuse proliferation of spindle and epithelioid cells within the superficial and deep reticular dermis, arranged in a nested and fascicular growth pattern (fig. 2, 3, 4).
The nests and fascicles are composed of large, oval to spindled cells with abundant amphophilic cytoplasm and little nuclear cytologic pleomorphism; occasional cells possess smudgy hyperchromatic nuclei. HE. x10.
dpa-0001-0029-g03.jpg
PMC4772936_01_dpa-0001-0029-g03.jpg
F3
Histopathologic examination revealed a diffuse proliferation of spindle and epithelioid cells within the superficial and deep reticular dermis, arranged in a nested and fascicular growth pattern (fig. 2, 3, 4).
The nests and fascicles are composed of large, oval to spindled cells with abundant amphophilic cytoplasm and little nuclear cytologic pleomorphism; occasional cells possess smudgy hyperchromatic nuclei. HE. x20.
dpa-0001-0029-g04.jpg
PMC4772936_01_dpa-0001-0029-g04.jpg
F4
Histopathologic examination revealed a diffuse proliferation of spindle and epithelioid cells within the superficial and deep reticular dermis, arranged in a nested and fascicular growth pattern (fig. 2, 3, 4).
Immunohistochemical staining positive for antibodies to NK1C3 (x20).
dpa-0001-0029-g05.jpg
PMC4772936_01_dpa-0001-0029-g05.jpg
F5
Immunohistochemical staining showed the tumor to be strongly positive for NK1C3 (fig. 5) and negative for S-100.