POU5F1 and neoplasm: The immunohistochemistry of the postoperative tumor tissue showed that cytokeratin(+), placental alkaline phosphatase (partial -/+), vimentin(-), cytokeratin CAM5.2(+), sal-like protein 4 (foci +), Ki67(65% +), human chorionic gonadotropin(-), CD34(-), Wilms’ tumor 1(-), calretin(-), D2-40(-), CD30(-), OCT3/4(-), programmed death ligand 1 (PD-L1)[combined positive score (CPS=2)](CPS was calculated as the number of PD-L1 staining tumor and immune cells divided by the total viable tumor cells multiplied by 100 with a maximum score of 100.