ENDOMETRIOSIS - The presence of endometrial tissue in places where it is normally not found. Often found on the surface of the ovaries or adjacent the uterus. Common symptoms include recurrent abdominal pain with menses, and abnormally heavy or prolonged periods. Infertility is also common with this condition. Diagnosis is often confirmed via laparoscopy. Treatment may include hormonal therapy or surgical resection of the ectopic endometrial tissue. Hysterectomy is warranted in select cases.