Endometrial polyps are a common gynecologic condition that most commonly presents clinically as abnormal vaginal bleeding. Endometrial polyps are found accidentally in asymptomatic women on physical examination for other symptoms. Ageing and hormone supplementation therapy are the main reasons for their high incidence. Malignant endometrial polyps are uncommon, but vaginal bleeding with age and after menopause often indicates the possibility of malignancy. With conservative treatment, up to 25% of endometrial polyps can regress, especially if they are <10 mm in diameter.
Hysteroscopic polypectomy is the main modality of treatment, and there is no significant difference in outcome depending on the mode of hysteroscopic polyp removal. Patients with symptomatic postmenopausal polyps require pathological sampling for evaluation, and removal of endometrial polyps in infertility may improve fertility. Blind curettage is not recommended if endometrial polyp removal can be performed under guided manipulation. The risks associated with hysteroscopic excision of polyps are low.
Endometrial polyps are localized endometrial overgrowths, either single or multiple, ranging from a few millimeters to several centimeters in diameter, and can be either non-tipped or tipped. Polyps consist of endometrial glands, mesenchyme and blood vessels. Risk factors for their development include age, hypertension, obesity and tamoxifen use. Endometrial polyps can be asymptomatic and when symptoms do develop, they usually include abnormal (including postmenopausal) uterine bleeding and infertility. Malignant endometrial polyps are rare, with a usual incidence of 0% to 12.9%, and depend on the study population.
Clinical presentation
Endometrial polyps are a common gynecologic disease, as many of them can be asymptomatic leading to an inexact incidence. The prevalence of endometrial polyps has been reported to be 7.8%-34.9%, depending on the population studied. Risk factors for the development of endometrial polyps include age, hypertension, obesity and tamoxifen use[3,4] . Increasing age seems to be a risk indicator for the development of endometrial polyps.
The prevalence of endometrial polyps seems to increase in women of childbearing age, but it is unclear whether their prevalence continues to increase or decrease after menopause. Reliable evidence confirming the above is known to be difficult to obtain. The finding of endometrial polyps seems to be associated with other benign conditions including uterine fibroids, cervical polyps and endometriosis.
Tamoxifen use is a specific risk factor for the development of endometrial polyps in women, with Class II studies reporting prevalence rates as high as 30% to 60% . The data on the ultimate relationship between hormone therapy and endometrial polyps are contradictory, as some studies report a higher prevalence of endometrial polyps in women using hormone therapy, while other studies have found the opposite. A progestin with high anti-estrogenic activity and the use of oral contraceptives may have a protective effect on the development of endometrial polyps. The efficacy of levonorgestrel IUD use as a treatment for endometrial polyps or to prevent their development has not been evaluated in low-risk groups.
The majority of women with symptomatic endometrial polyps present with abnormal uterine bleeding, which has recently been classified as AUB-P (abnormal uterine bleeding due to polyps) in premenopausal women and recognized by FIGO . Endometrial polyps are found in 10-40% of premenopausal women with abnormal uterine bleeding[14,16,20] and the severity of symptoms is not related to the number, diameter and location of polyps.
The incidence of endometrial polyps appears to be increased in infertile women. In a large prospective trial including 1000 infertile women who underwent in vitro fertilization, the prevalence of endometrial polyps was 32%. The high prevalence of endometrial polyps in infertile women suggests a causal relationship between endometrial polyps and infertility. However, the causal relationship between endometrial polyps and infertility seems to have been confirmed in a randomized trial.
Atypical hyperplasia and endometrial cancer originating from endometrial polyps are rare though. However, the results of a previous case series showed that the malignancy rate of endometrial polyps ranged from 0% to 12.9%.
Most authors believe that the risk of malignant endometrial polyps increases with age, whereas the risk of malignant polyps in premenopausal women seems to be low. The presence of symptoms (abnormal uterine bleeding) has been identified as an indicator of the risk of possible malignancy of endometrial polyps. Polyp size also appears to be a risk indicator for malignant endometrial polyps . Other known risk factors for endometrial cancer such as obesity, diabetes mellitus, and hypertension have been reported to increase the risk of endometrial polyp malignancy, although the reported results are inconsistent. The use of tamoxifen increases the risk of endometrial atypical hyperplasia and endometrial polyp malignancy.
Knowledge of the course and clinical prognosis of untreated endometrial polyps is limited. In the Class II study, the rate of spontaneous regression of endometrial polyps after 1 year of follow-up was 27% . Polyps that do resolve spontaneously tend to be smaller than those that persist .
Guidelines for identifying the presence of endometrial polyps
1, Aging is the most common risk factor for the development of endometrial polyps (Grade B).
2. For women with endometrial polyps, abnormal uterine bleeding is the most common symptom (Grade B).
3, Women who are infertile are more likely to have endometrial polyps (Grade B).
4, The spontaneous regression rate of endometrial polyps is as high as 25%, and small polyps are more likely to regress spontaneously (Grade A).
5, Such as tamoxifen-like drugs may induce endometrial polyp formation (Grade B).
Increasing age leading to polyp malignancy is rare; abnormal uterine bleeding symptoms and tamoxifen use however increase the likelihood of polyp malignancy (Grade B).
Blind examination
Blind dilatation, curettage or endometrial biopsy is inaccurate for the diagnosis of endometrial polyps, i.e. its specificity and positive predictive value is 100% . Compared to hysteroscopy-guided biopsy, blind examination has a low sensitivity of 8% to 46% and a negative predictive value of 7% to 58%, so this technique should not be used for diagnosis. Blind examination can also lead to fragmentation of polyps and make histological diagnosis difficult.
Hysteroscopically guided biopsy
Hysteroscopy-guided biopsy is the most common method for the diagnosis of polyps than other methods because it is the conservative measure with the highest sensitivity and specificity. Diagnostic hysteroscopy alone allows only subjective evaluation of lesion size and characteristics and has been reported to have a sensitivity of 58% to 99%, specificity of 87% to 100%, positive predictive value of 21% to 100%, and negative predictive value of 66% to 99% compared to hysteroscopy-guided biopsy [13,54,56,72,78,79]. The choice of diagnostic (and therapeutic) method for inpatients or outpatients depends on the availability of instruments, patient selection and the skill level of the physician.
Other diagnostic methods
Compared to hysteroscopy for the diagnosis of endometrial polyps [70] iodine oil imaging of the uterine tubes has a higher sensitivity of 98%, but a lower specificity (34.6%). Ionizing radiation, iodine-containing contrast agents and the discomfort caused by this test limit the use of this test for the diagnosis of endometrial polyps. With magnetic resonance imaging systems, endometrial polyps can be visualized as low signal intensity shadows surrounded by high signal intensity fluid in the uterine cavity, and the endometrium is visualized by T2-weighted magnetic resonance imaging. The very high cost, limited availability and limited advantages over ultrasound prevent the routine use of this technique. Compared to vaginal ultrasound, computed tomography and even contrast-enhanced CT are of limited clinical use due to their 53% lower sensitivity.
Diagnostic guidelines for endometrial polyps
1, Vaginal ultrasound provides reliable information for the detection of endometrial polyps and should be selected among those suitable for application (class B).
2, Color or energy Doppler improves the ability of vaginal ultrasound to diagnose endometrial polyps (Level B).
3, The application of intrauterine contrast ultrasound (with or without 3D imaging) improves the diagnostic ability of endometrial polyps (Grade B).
4, Blind dilation, scraping or biopsy should not be used for the diagnosis of endometrial polyps (Grade B).
[Treatment
Conservative treatment
Given that most polyps are nonmalignant, one approach is expectant therapy without intervention. class II evidence shows that about 25% of polyps regress spontaneously and that smaller polyps are more likely to regress than polyps greater than 10 mm in length. Postmenopausal asymptomatic polyps are unlikely to be malignant and, after discussion and information with the patient, may be treated conservatively with observation.
Medication
Medication has a limited role in the management of endometrial polyps. Although gonadotropin-releasing hormone analogs may be used as adjuvant therapy prior to hysterectomy, this must be done considering the cost of the medication, its side effects and the advantages and disadvantages of the resection procedure alone. There are no data to support treatment with gonadotropin-releasing hormone analogs in this setting.
The use of certain types of hormone therapy may have a preventive effect on polyp formation. The use of levonorgestrel IUDs in women taking tamoxifen has been reported to reduce the incidence of endometrial polyps. However its use in polyp treatment is currently limited to the research field[85] .
Conservative surgical treatment
In a Class II study, blind dilation and curettage was reported to remove endometrial polyps 4/51 (8%), while the rate of polyp clamp removal increased to 21/51 (41%). class II-2 and II-3 studies have shown that removal of endometrial disease by blind curettage is less than 50% successful and in many cases incomplete[74,75,86-88] . When hysteroscopic treatment is feasible, blind curettage should not be used as a diagnostic or therapeutic intervention. When endometrial polyps are diagnosed or suspected and hysteroscopy is not feasible, the patient should be converted to give the appropriate treatment.
Hysteroscopic electrodesiccation
Hysteroscopic polyp removal is effective and safe as a diagnostic and therapeutic intervention. There are various methods of hysteroscopic removal of polyps; however, there are no comparative studies based on efficacy or cost of these methods, and the choice of method is related to the training and proficiency of the clinician.
Hysteroscopic polypectomy is commonly used and relatively inexpensive. Its visualization and direct removal have been reported to be effective and reduce recurrence rates compared to visual removal of polyps with polyp forceps. Other devices include bipolar systems and hysteroscopic crushers, whose availability is limited based on the availability of these techniques, single-use costs, and specialized equipment.
Few prospective studies have evaluated the efficacy of polypectomy for symptom improvement. A Class I study on this issue showed that 150 women with endometrial polyps underwent hysteroscopic excision and were observed for 6 months. Although there was a significant improvement in symptoms after polypectomy, such as intermenstrual bleeding, there was no significant difference in the amount of menstrual blood loss between the groups.
The risk of uterine adhesions was low because polypectomy did not involve the myometrium, and the Class I study reported no uterine adhesions after hysteroscopic polypectomy .
Radical surgical treatment modalities
Hysterectomy has no potential for polyp recurrence or malignancy; however, it is a costly and important surgical procedure with some potential for morbidity. The procedure should only be performed appropriately if the implications of the procedure are discussed with the patient and the risks are clear. There are no comparable data on conservative and radical treatment options.