An ovarian cyst is a sac or pouch filled with fluid or other tissue that forms on the ovary. It is normal for a small cyst to develop on the ovaries. In most cases, cysts are harmless and go away on their own. In other cases, they may cause problems and need treatment.
In the US, a woman has a lifetime risk of 5-10% of undergoing surgery for a suspected ovarian cyst or tumor. Out of this group, 13-21% of women are diagnosed with ovarian cancer. Thus most ovarian masses are benign. The most common ovarian mass in a menstruating woman is a functional simple ovarian cyst that resolves by her next menstrual cycle. In a post-menopausal woman, the most common ovarian mass is a non-cancerous cystadenoma. The goal of evaluation is to rule out cancer. Management decisions are often based on patient’s age, family history, patient’s symptoms, imaging studies, and blood testing results.