Endometrial polyps are hyperplastic or large growth proliferations of the endometrial glands as well as the tissue surrounding the blood vessels. It forms protrusions on the surface of the endometrium and in the internal phase of the uterine cavity, which is responsible for harboring the embryo during pregnancy, as well as menstrual cycles.
Thanks to advances in transvaginal ultrasound and diagnostic hysteroscopy, more cases of this pathology are being diagnosed. The most commonly encountered pathology is polyps, which cause the majority of surgical hysteroscopies.
Why do endometrial polyps occur?
The main cause is an alteration in the balance of estrogen or progesterone levels, the hormones that regulate the proliferation and menstrual release of the endometrium. There are higher levels of estrogen and progesterone receptors inside the polyps than in the surrounding normal endometrium. Both help this irregular growth of the endometrial glands and their vascularization, giving rise to polyps.
What symptoms do endometrial polyps produce?
Most endometrial polyps do not produce symptoms and are diagnosed with a routine examination with the specialist in Gynecology and Obstetrics.
If they do produce any symptoms it is usually as abnormal uterine bleeding, this being the main symptom, which occurs in 64 to 88% of women who have polyps. On the other hand, intermenstrual bleeding is the most common symptom in premenopausal women with polyps. However, this bleeding is usually minimal and produces only mild spotting.
Postcoital bleeding is also common, as is the finding in asymptomatic patients who present for infertility. Postmenopausal women with polyps often have intercurrent postmenopausal bleeding during hormone therapy.
It is rare that the endometrial polyp can be seen during speculum examination at the external cervical os. Polyps with prolapse may or may not produce symptoms.
What risk factors influence endometrial polyps?
Some factors increase the frequency of polyps:
- High blood pressure.
- Diabetes.
- Obesity.
- Age over 40 years, with a higher prevalence between 45-50 years of age.
- Some medications, such as tamoxifen (administered in patients diagnosed with some types of breast cancer to prevent recurrences).
What types of endometrial polyps are there?
Endometrial polyps can be divided into:
- Typical or functional (20%), which have a similar appearance to the endometrium in its normal appearance.
- Atrophic (40%), which undergo changes with a tendency to regress or retarded growth. These are the polyps usually found in menopausal patients.
- Hyperplastic (35%), which produce changes indicating accelerated growth.
- Malignant (1-5%), which contain cancerous cells inside.
The term “pseudopolyp” refers to some thickened areas of the endometrium, with the appearance of a polyp, smaller than 1 cm, which disappear with menstruation, since they do not have their own blood vessels.
As for the probability or risk of malignancy, it is estimated that 95% of endometrial polyps are benign. A review of 17 observational studies of more than 10,000 women showed that the incidence of malignant or hyperplastic polyps was higher in premenopausal women (5.4% vs. 1.7%) and in women with bleeding compared to those without bleeding (4.2% vs. 2.2%).
How are endometrial polyps diagnosed?
Ultrasound can be useful in the diagnosis of an endometrial polyp, either by direct visualization of the polyp and its vascularization with color Doppler ultrasound, or indirectly, by detecting an area of abnormal endometrial growth. Other techniques that can help are hysterosalpingography (radiography of the fallopian tubes) and sonohysterography or ultrasound with fluid infusion inside the uterus.
However, the gold standard diagnostic test for polyps is hysteroscopy, since it makes it possible to locate and confirm the lesion, evaluate the state of the endometrium and make an anatomopathological diagnosis by taking biopsies of the polyp and the endometrium, with a specificity and sensitivity of 95-100%. This test allows early diagnosis of diseases such as endometrial hyperplasia or different types of endometrial carcinoma.
Other techniques that preceded hysteroscopy, such as uterine curettage, left more than 10% of polyps undiagnosed. There is evidence that, in postmenopausal women with bleeding and thickened endometrium, and a negative blind endometrial biopsy (no hysteroscopic view), 3% of women were shown to have undiagnosed endometrial cancer, and 3% had endometrial hyperplasia with atypia in polyps.
How should an endometrial polyp be treated?
In general, the removal of any polyp that presents symptoms, that is to say, that causes some type of bleeding or infertility, is indicated.
In premenopausal patients, polyps are usually asymptomatic, of a functional type and less than 10mm. In these cases it may only be necessary to maintain an expectant attitude, doing ultrasound controls every 6 months to analyze their possible growth.
Post-surgical advice after the removal of endometrial polyps
Hysteroscopic polypectomy is a fairly simple technique that is usually performed on an outpatient basis. However, the patient may experience slight genital bleeding in the days following the procedure or mild discomfort, which usually subsides by taking anti-inflammatory drugs (NSAIDs). Most patients return to normal routine within a few days.