Uterine or endometrial polyps are overgrowths of the inner lining of the uterus. Women with polyps usually present with irregular or heavy vaginal bleeding. Single or multiple polyps can range from a few millimeters to several centimeters in size.
No definitive cause of endometrial polyps is known, but they appear to be affected by hormone levels and grow in response to estrogen circulating in the blood.
Endometrial polyps are rare among women younger than 20 years of age. The incidence rises steadily with increasing age, peaks in the fifth decade of life, and gradually declines after menopause. Obesity increases the levels of estrogen in the blood, so also will increase the risk of uterine polyps. Tamoxifen therapy is also a risk factor for the development of endometrial polyps; 8-36% of postmenopausal women treated with tamoxifen develop polyps.
Irregular bleeding, including spotting, is the most frequent symptom in women with endometrial polyps. Less frequent symptoms include heavy bleeding, postmenopausal bleeding, and prolapse of the polyp through the cervix. Many polyps are asymptomatic.
Diagnosis can only be confirmed after removal of a specimen. A special type of ultrasound called a saline infusion sonogram (SIS) is the most useful noninvasive modality for evaluating the presence and size of polyps.
A polypectomy is a procedure to remove a polyp. The most effective way to perform a polypectomy is through hysteroscopy, when a small camera is placed inside the uterus for visualization. This is usually performed in the operating room under anesthesia. In infertile women with endometrial polyps, removal may improve fertility. In the absence of risk factors for endometrial hyperplasia or cancer (obesity, older age, history of breast cancer, hypertension, diabetes), asymptomatic polyps of ≤2 cm in premenopausal women are likely to go away. Therefore, these patients can chose to be followed closely instead of having surgery.
Most patients with symptoms will experience improvement after removal. The great majority (>95%) of endometrial polyps are benign, but women who experience bleeding symptoms or who are postmenopausal are more likely to have a cancerous or precancerous polyp.
After removal, a polyp may recur. Other than decreasing one’s risk factors such as obesity, an oral progestin or a progestin-releasing intrauterine device (Mirena®) could be used to prevent recurrence. Endometrial ablation is also an option for women who have completed their childbearing.