An endometrial polyp or uterine polyp is a mass in the inner lining of the uterus. They may have a large flat base (sessile) or be attached to the uterus by an elongated pedicle (pedunculated). Pedunculated polyps are more common than sessile ones. They range in size from a few millimeters to several centimeters. Small blood vessels may be present, particularly in large polyps. Bleeding from the blood vessels of the polyp contributes to an increase of blood loss during menstruation and blood "spotting" between menstrual periods, or after menopause. If the polyp protrudes through the cervix into the vagina, pain (dysmenorrhea) may result. The use of an intrauterine system containing levonorgestrel in women taking tamoxifen may reduce the incidence of polyps.
Diagnosis
thumb|right|200px|[[Micrograph of an endometrial polyp. H&E stain.]]
thumb|Myometrium (smooth muscle cells) versus endometrial stroma (more cellular) versus endometrial polyp stroma (more collagenous). H&E stain
Endometrial polyps can be detected by vaginal ultrasound (sonohysterography), hysteroscopy and dilation and curettage.
Endometrial polyps can be solitary or occur with others. They are round or oval and measure between a few millimeters and several centimeters in diameter. When curettage is performed without hysteroscopy, polyps may be missed. To reduce this risk, the uterus can be first explored using grasping forceps at the beginning of the curettage procedure.
Prognosis
Endometrial polyps are usually benign although some may be precancerous or cancerous. Polyps can increase the risk of miscarriage in women undergoing IVF treatment.
Epidemiology
Endometrial polyps usually occur in women in their 40s and 50s.