Fig. 3

Immunostaining findings. Actin (sm) was positive in the smooth muscle cells (black arrow) in the muscularis of the rectum and negative in the submucosa (gray arrow) of the rectum and the endometrial interstitium (the white arrow). CD10 was positive in the endometrial interstitium (black arrow). CK and ER were positive in the epithelial cells of the endometrium (black arrows). The Ki67 index in the ectopic endometrial tissues was approximately 5% (black arrow). Negative control shows a representative negative control for CK immunostaining obtained by the omission of the primary antibody. Scale bar: actin (sm) (left), CK, CD10, ER, negative control: 20 μm; actin (sm) (right), Ki67: 40 μm