726815.fig.002a
(a)
726815.fig.002b
(b)
726815.fig.002c
(c)
726815.fig.002d
(d)
726815.fig.002e
(e)
726815.fig.002f
(f)
726815.fig.002g
(g)
726815.fig.002h
(h)
Figure 2: Photomicrographs of histological and immunohistochemical findings. Nests containing biphasic cell populations within dense connective tissue are shown. The presence of small neuroblast-like cells with delicate fibrils between them (indicated by dashed arrows) and large melanin-containing cells (indicated by arrows) were observed (H&E, magnification 400) (a). Large epithelial-like cells were positive for cytokeratin AE1/AE2 (b) (magnification 100), epithelial membrane—EMA (c) (magnification 400), and HMB45 (d) (magnification 100). Both cell types were positive for vimentin, but the signal intensity was stronger in large cells (e). Both cell types were also positive for chromogranin, but the signal intensity was stronger in small cells (f) (magnification 100). Synaptophysin was expressed by small neuroblast-like cells (magnification 100) (g). Nuclear expression of Ki67 was also observed (magnification 100) (h).