The risk of malignancy with an apparently simple adnexal cyst on ultrasound.

We received data of 144 patients, who had been operated upon in the 2nd Department of Obstetrics and Gynecology in Vienna because of persisting sonographically detected "simple" adnexal cysts. Only 3 cysts were malignant (one of them borderline). All three patients were postmenopausal. The mean diameter of the malignant cysts were 7, 11 and 18 cm, respectively. 82 sonographically simple cysts were histologically benign. We found 27 cysts associated with chronic pelvic sepsis (hydrosalpinx and pseudocysts), 22 were benign cystadenomas and 10 were endometriotic.