Fig. 1

(a) The tumor infiltrated into the deep muscular layers. (HE; original magnification, × 25) (b) The tumor took the form of nest-like, trabecular and rosette-like structures. (HE; original magnification, × 100) (c) The tumor cells had relatively abundant eosinophilic cytoplasm and nuclei containing dense granular chromatin. The mitotic figure was observed. (HE; original magnification, × 400) (d) Immunohistochemically, the tumor cells were positive for Cg A. (e) Immunohistochemically, the tumor cells were positive for Syn. (f) The index of Ki-67 was 5%. (d-f immunohistochemical staining; original magnification, × 100)