Endometrial polyps are localized overgrowths of the inner lining of the uterus (endometrium) that project into the uterine cavity. Only a small percentage of these polyps are cancerous. The most common symptom is abnormal uterine bleeding. They may be seen by ultrasound (saline hysterosonography), x-ray (hysterography), or hysteroscopy. Endometrial polyps are usually removed during hysteroscopy with directed biopsy or with polyp forceps.