An ovarian cyst is a sac filled with fluid, or a semisolid material, that develops on or within the ovary. Ovarian cysts are relatively common and usually disappear without treatment.
Update Date 4/5/2016
Updated by: Irina Burd, MD, PhD, Associate Professor of Gynecology and Obstetrics at Johns Hopkins University School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.