A post-menopausal woman presented with an asymptomatic 3.0 cm simple ovarian cyst. Of the following statements, the one that is TRUE is that the cyst should be removed if the patient has an increased serum CA-125 level. A simple cyst under 5.0 cm in diameter in a post-menopausal woman has a very low risk of malignancy and can be followed with serial ultrasounds without surgery. The most common neoplasm found on surgical removal of these cysts is a serous cystadenoma, not a fibrothecoma.