Received 13 July 2009; received in revised form 18 September 2009; accepted 18 November 2009. published online 25 January 2010.
The purpose of this study was to measure the occurrence and natural history of simple ovarian cysts in a cohort of older women.
Simple cysts were ascertained among a cohort of 15,735 women from the intervention arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial through 4 years of transvaginal ultrasound screening.
Simple cysts were seen in 14% of women the first time that their ovaries were visualized. The 1-year incidence of new simple cysts was 8%. Among ovaries with 1 simple cyst at the first screen, 54% retained 1 simple cyst, and 32% had no cyst 1 year later. Simple cysts did not increase risk of subsequent invasive ovarian cancer.
Simple ovarian cysts are fairly common among postmenopausal women, and most cysts appear stable or resolve by the next annual examination. These findings support recent recommendations to follow unilocular simple cysts in postmenopausal women without intervention.