What are polyps?
Polyps, along with fibroids, are among the most common gynecological conditions. Polyps are benign growths located either on the inner lining of the uterus (endometrial polyps) or on the cervix (cervical polyps).
Polyps are hormone-dependent, as their pathogenesis appears to be related to the effect of estrogen on the endometrium. They usually occur in about 10% of women around the age of 40–50.
Histologically, endometrial polyps are classified as:
• Adenomatous polyps: the most common type. They consist of fibrous tissue and endometrial glands. Squamous metaplasia of the epithelial lining is common, and very rarely adenocarcinoma develops within them.
• Placental polyps: rare; caused by retained placental tissue after childbirth or pregnancy termination. They consist of remnants of chorionic tissue and fibrous stroma.
Morphologically, polyps may have a broad, flat base or be attached to the uterus with a stalk (pedunculated polyps). Pedunculated polyps are more common. Their size ranges from a few millimeters to several centimeters, and they are supplied by small blood vessels.
Polyps rarely contain cancer cells, but the risk is higher in women over 40. About 75% of polyps are benign, while the rest represent precancerous lesions such as simple hyperplasia, complex hyperplasia, or atypical hyperplasia. The incidence of cancer within a polyp is up to 3% and increases after menopause.
What symptoms do uterine polyps cause?
Polyps rarely cause symptoms, and their diagnosis is usually incidental during routine gynecological check-ups (ultrasound for endometrial polyps or pelvic exam for cervical polyps). When symptoms occur, they may include:
• Menstrual cycle irregularities: from light spotting to heavy menstrual bleeding (menorrhagia) and prolonged periods.
• Abnormal uterine bleeding: bleeding between periods (metrorrhagia), mid-cycle spotting, or bleeding in postmenopausal women.
• Bleeding after sexual intercourse.
• Pain: rarely, pain during the first days of menstruation or general pelvic pain, especially if pedunculated polyps grow large and protrude into the vagina.
• Infertility: a large endometrial polyp may prevent implantation of the fertilized egg.
• Recurrent miscarriages: Studies (e.g., Valli et al.) show polyps are more frequent in women with recurrent pregnancy loss (32%) compared to healthy controls (9%).
Risk factors for endometrial polyps
High BMI (obesity), hypertension, hormonal replacement therapy, and use of medications such as tamoxifen increase the risk of developing polyps. Since polyps are estrogen-dependent, all these conditions affect estrogen levels. Endometrial polyps are commonly found in women with a history of cervical polyps and in about 25% of women with abnormal uterine bleeding.
Diagnosis of endometrial polyps
Diagnosis is not always easy unless the polyp protrudes through the cervix. Diagnostic tools include:
• Transvaginal ultrasound (TVS): polyps appear as small, heterogeneous areas within the endometrium. Best performed after menstruation when the endometrium is thinner. Techniques like saline infusion sonography (SIS) and 3D TVS improve detection but are not 100% accurate, and distinguishing polyps from submucosal fibroids may be challenging.
• Hysterosalpingography: involves injecting contrast through the cervix to visualize the uterine cavity and tubes. Not the preferred method for diagnosing polyps; used mainly in infertility evaluation.
• Hysteroscopy: the gold standard for diagnosing endometrial polyps. Using a small camera (hysteroscope), the physician directly visualizes the uterine cavity, identifies polyps and other abnormalities (e.g., hyperplasia), performs biopsies, and removes polyps.
Removal of endometrial polyps
Treatment is always surgical. Hysteroscopy is the modern method of choice, allowing full visualization of the endometrium and precise removal of the polyp’s stalk without damaging surrounding tissue. Blind curettage fails to remove polyps completely in 1/3 of cases.
During hysteroscopy, if a polyp is found, it is removed, and an additional endometrial curettage is performed. The tissue is sent for histology to exclude malignancy or precancerous changes. Removal improves fertility, prevents endometrial cancer, and treats menstrual irregularities—unless other causes coexist.
The likelihood of malignancy is low (0.5–4.8%).
Women with symptoms suggesting an endometrial or cervical polyp should undergo immediate evaluation, as the differential diagnosis includes endometrial cancer and cervical cancer.