Endometrial Polyps: Causes, Symptoms, and Treatment
The endometrium is the inner lining of the uterine cavity. Endometrial polyps (also called uterine polyps) are growths inside the uterus. They can be single or multiple. Their size ranges from a few millimeters to several centimeters.
Endometrial polyps may not cause any symptoms, but if they do, the most common symptoms are abnormal vaginal bleeding (excluding spotting before or after menstruation) or infertility (since polyps can interfere with normal implantation of the egg). Malignant tumors are rare in polyps. However, there is a small chance that a tumor diagnosed as a polyp may turn out to be malignant (this is not a diagnostic error, but a rare form of endometrial cancer that may initially appear as a polyp on ultrasound).
Article contents:
Endometrial polyps are a very common gynecological condition. Studies show that the prevalence of endometrial polyps ranges from 8% to 35%. The exact cause of polyps is unknown, but risk factors include age, hypertension, obesity, and tamoxifen use. Hormonal contraceptives can prevent the development of endometrial polyps but do not treat them.
Clinical manifestations of endometrial polyps
Polyps may be asymptomatic, but they can cause bleeding during menstruation or be a factor in infertility.
Polyps are found in 10–40% of women, with varying degrees of symptom severity.
The prevalence of endometrial polyps is higher among women with infertility. For example, the prevalence of endometrial polyps is 32% among women referred for IVF. Although a causal link between polyps and infertility has not been 100% proven, removing polyps in infertile women increases their chances of having a child.
The risk of finding a malignant tumor in polyps is low, but it increases with age. The presence of symptoms and the size of the polyp are risk factors for the likelihood of finding a malignant tumor in polyps.
Diagnosis of endometrial polyps
Ultrasound examination (US)
Ultrasound examination is the most commonly used method for diagnosing endometrial polyps. The diagnostic value of this method depends heavily on the examiner’s expertise: sensitivity ranges from 19% to 96%, and specificity from 53% to 100%.
The use of Doppler ultrasound imaging (an additional ultrasound technique) increases sensitivity to 91–97%.
Injecting a contrast agent into the uterine cavity during an ultrasound examination can increase the test’s sensitivity for detecting small polyps.
Three-dimensional ultrasound also increases sensitivity compared to two-dimensional ultrasound, but these changes are not significant enough to recommend three-dimensional ultrasound as a standard method for diagnosing endometrial polyps.
Dilation and curettage (D&C)
Dilation and curettage is not an accurate method for diagnosing endometrial polyps. The sensitivity of this approach ranges from 8% to 46%, so it is not recommended as a method for diagnosing or treating endometrial polyps.
Hysteroscopy
Hysteroscopy with targeted biopsy (examination of the uterine cavity using specialized equipment with a camera—the biopsy involves “removing” the polyp and examining the excised tissue) is the most accurate method for diagnosing endometrial polyps. It offers high sensitivity and reliability in diagnosing the condition. It is important to note that hysteroscopy without biopsy is a less informative method (it detects only 58% of polyps).
Hysterosalpingography
Hysterosalpingography (a procedure using a dye injected into the uterus—typically used to monitor eggs) offers high sensitivity but very low specificity (35%) for detecting endometrial polyps.
Magnetic resonance imaging (MRI)
Magnetic resonance imaging can detect endometrial polyps, but it is too expensive to recommend for this purpose.
Computed tomography (CT)
Computed tomography should not be used, as its sensitivity is only 53%.
A brief overview of diagnosis:
- Ultrasound is a suitable method for diagnosing endometrial polyps.
- Doppler imaging, contrast enhancement, and 3D imaging improve the diagnostic accuracy of ultrasound.
- Do not use diagnostic curettage as a method for diagnosing endometrial polyps.
Treatment of endometrial polyps
If polyps are suspected, they may be monitored if they do not cause symptoms, as malignant tumors are unlikely to be detected. In approximately 25% of cases, polyps resolve on their own. Most often, small polyps (<1 cm) disappear on their own.
Medical treatment
Options for hormonal treatment of endometrial polyps are being actively studied, but none of the treatment methods has yet proven effective and can be implemented. At the same time, some hormonal treatment options may be justified to prevent the recurrence of endometrial polyps. For example, intrauterine devices containing levonorgestrel reduce the likelihood of polyps developing in women receiving tamoxifen.
Surgical treatment
Uterine ablation removes endometrial polyps in 4–50% of patients. This may explain the high rate of “recurrence” of endometrial polyps after treatment. Due to its low efficacy, uterine ablation cannot be recommended as an appropriate treatment for endometrial polyps.
The optimal treatment for endometrial polyps is targeted biopsy and hysteroscopy with multiple excisions (a hysteroscope is inserted into the uterine cavity to identify and remove the polyp. The tissue is then sent for histological examination).
Removal of an endometrial polyp this approach eliminates intermenstrual bleeding and improves the chances of conception in women of pre-fertile age. After polyp removal, fertility rates in infertile women range from 43% to 80%.
The recurrence rate of polyps following successful treatment (hysteroscopic polypectomy) is 2–4%.
The only way to guarantee that polyps will not recur is to remove the uterus. This method cannot be recommended as the treatment of choice for endometrial polyps, since polyps very rarely cause life-threatening symptoms or lead to malignant diseases.
In summary:
- If small polyps are detected, they can be monitored if their presence is not accompanied by bleeding during menstruation or infertility.
- Treatment of endometrial polyps is not recommended.
- Hysteroscopy with polypectomy is the gold standard for treating endometrial polyps.
- After polyp removal, histological examination of the tissue obtained during the procedure must be performed.
- In infertile women, polyp removal increases the chances of conceiving a child, both in natural cycles and with IVF.
- Most pregnancies in women with polyps proceed normally. There is no need to remove the polyps or terminate the pregnancy.
