This disease process afflicts approximately 10% of women and can cause infertility and/or pelvic pain. Endometriosis is a condition where cells from the endometrium, the lining of the uterus, implant outside of the uterine cavity, most commonly in places such as the pelvis and the ovaries. Sometimes, cysts in the ovaries may be composed of endometriosis. Less commonly, endometriosis can be found in other parts of the body. Treatment options for endometriosis include medical and/or surgical methods.