The distinction between malignant and benign ovarian cysts has three main aspects: first, the growth rate of ovarian cysts, if the size of ovarian cysts changes a lot and grows rapidly in a short period of time, consider the possibility of malignancy, if the growth rate is slow and changes are not significant consider benign mostly. Secondly, changes in ultrasound images, malignant ovarian cysts are realistic, cystic or mixed cysts under ultrasound, with impure internal echogenicity, papillary projections and unsmooth edges, which are considered more likely to be malignant, while benign ovarian cysts are usually of medium size or small, with pure internal echogenicity and smooth edges. Third, the difference in clinical symptoms, malignant ovarian cysts are mostly associated with ovarian cancer, for example, ovarian granulosa cell tumor and follicular membrane cell tumor are low-grade malignant ovarian tumors, which can secrete estrogenic substances, so they can cause irregular vaginal bleeding, endometrial thickening of different degrees and menstrual changes, while benign ovarian cysts do not secrete any hormones, so they will not affect the changes in the menstrual cycle and will not appear. Irregular vaginal bleeding.