Ovarian cancer can be large or small, small ones can be as small as 2-3 cm, and large ones can be as large as 10 to 20 cm or even larger. When the ovarian tumor invades the pelvic cavity, abdominal cavity or even distant metastasis, it becomes an advanced ovarian tumor, so the size of ovarian tumor cannot be judged as benign or malignant by its size. Ovarian cancer is one of the more difficult tumors to treat among the three major gynecological tumors, because most ovarian cancer patients have already reached advanced stage when obvious symptoms appear. Therefore, it is very necessary for women to have regular gynecological checkups every year, which can detect early ovarian tumors in time and allow patients to receive timely treatment.