Ovarian teratoma is a common type of ovarian germ cell tumor. It does not evolve after a woman has conceived a freak baby, but is caused by abnormal germ cell proliferation and is a tumor that grows in the ovarian tissue formed by abnormal germ cell proliferation and aggregation. Because germ cells contain ectodermal, mesodermal and endodermal tissues, the tumor may contain ectodermal tissues such as hair, oil, skin, teeth and bone fragments, and may also contain mesodermal or endodermal tissues such as muscle, gastrointestinal and thyroid tissues. The cause of ovarian teratoma is unknown, and there are several types, including mature teratoma and immature teratoma. Ninety-seven percent of them are mature teratomas, also known as dermatomal cysts. Cortical cysts are one of the most common types, accounting for 10-20% of all ovarian tumors and 85%-97% of germ cell tumors. Because it is not related to pregnancy, ovarian teratoma can occur at any age. It can occur in newborns, adolescents, middle-aged or elderly people, but 80%-90% are women in their 20-40 years of reproductive age, accounting for about 1/4-1/3 of ovarian tumor patients. Ovarian teratoma is usually clinically The tumor is usually asymptomatic, but when it grows up, it may have abdominal distension, mild abdominal pain and pressure symptoms. Ovarian teratoma is usually clinically asymptomatic. When is the best time to treat ovarian teratoma? In principle, ovarian teratoma should be treated as soon as it is detected, regardless of its size, to avoid malignant transformation of benign teratoma and to prevent complications such as tumor reversal, infection, rupture and bleeding. The key point of surgery for ovarian teratoma is to remove the tumor completely without opening the abdomen and treat it with minimally invasive laparoscopic surgery.