Ovarian teratoma 16mmx15mm suggests observation and regular review. Ovarian teratoma is a tumor originating from ovarian germ cells, and there is no indication for surgery for an ovarian teratoma of 16mmx15mm size. Gynecological ultrasound and tumor markers are recommended to be repeated every six months. If the ovarian teratoma is not enlarged and the tumor marker is normal, regular review is sufficient. If the tumor marker is abnormal or the ovarian teratoma is larger than 30mmx30mm, surgery is needed as soon as possible. Surgery is preferred to laparoscopic ovarian teratoma excision. Postoperative specimens are routinely sent for pathological examination, and if the pathology report is malignant, it is necessary to perform hysterectomy plus double adnexectomy again, or even radiotherapy. If you find ovarian teratoma in the clinic, you should go to the regular hospital, complete the examination, and follow the doctor’s instructions for diagnosis and treatment.