Endometrial polyps are localized overgrowths of the uterine endometrium. They may occur singly or in multiples, with diameters ranging from a few millimeters to several centimeters. Polyps can be pedunculated or sessile. The prevalence among individuals of reproductive age, perimenopausal, and postmenopausal populations is estimated at 7.8%–34.9%. Endometrial polyps account for 10%–40% and 10.1%–38.0% of abnormal uterine bleeding in premenopausal and postmenopausal women, respectively. According to the WHO histological classification of tumors of the female reproductive system, endometrial polyps are categorized as uterine tumor-like lesions.
High-Risk Factors
Endocrine Factors
The formation of endometrial polyps is strongly associated with elevated levels of estrogen. Hormone replacement therapy in perimenopausal and postmenopausal women, as well as the prolonged use of hormone-containing supplements, may increase estrogen levels in the body.
Inflammatory Factors
Long-term gynecological inflammation, the presence of intrauterine foreign bodies, childbirth, abortion, postpartum infections, surgical interventions, or mechanical stimulation are all potential triggers for the development of endometrial polyps.
Other Factors
Advanced age, hypertension, obesity, diabetes, and prolonged use of tamoxifen after breast cancer surgery are additional high-risk factors for developing endometrial polyps.
Clinical Presentation
The primary symptoms of endometrial polyps include intermenstrual bleeding, menorrhagia, extended menstrual periods, or irregular bleeding. Solitary or smaller polyps are often asymptomatic and may only be discovered during ultrasound examination, diagnostic curettage, or post-hysterectomy. While endometrial polyps are benign lesions, the concurrent or subsequent occurrence of endometrial hyperplasia and endometrial carcinoma has been reported in 11%–30% and 0.5%–3% of cases, respectively. High-risk factors for malignant transformation include abnormal uterine bleeding, postmenopausal status, and metabolic syndromes such as obesity, diabetes, and hypertension, as well as the use of tamoxifen.
Diagnosis
A preliminary diagnosis can be made based on clinical symptoms, gynecological examination, and ultrasound findings. Confirmation requires pathological examination following polyp removal. Histopathologic diagnosis typically meets at least two of the following criteria:
- Glands and stroma within the polyp show asynchronous development relative to the surrounding endometrial tissue.
- Glandular arrangement appears disorganized.
- Stromal fibrosis and thick-walled blood vessels are present.
Based on their pathogenesis and histological features, endometrial polyps can be classified as non-functional polyps, functional polyps, adenomyomatous polyps, tamoxifen-induced polyps, atrophic polyps, and endometrial-endocervical polyps.
Treatment
Treatment of endometrial polyps includes expectant management, medical therapy, and surgical intervention. For patients with fertility desires, the treatment goals focus on alleviating symptoms, preserving the endometrium, enhancing fertility, and preventing recurrence. For those without fertility requirements, the objectives include lesion removal, symptom improvement, recurrence reduction, and prevention of malignant transformation.
Expectant Management
Small, asymptomatic polyps (<1 cm in diameter) in premenopausal women have a natural regression rate of 6.3%–27% within one year. Observation and follow-up may be appropriate for premenopausal patients with no symptoms, no high-risk factors for malignancy, and polyps smaller than 1 cm.
Medical Therapy
Medical treatment is rarely used as a standalone option but is primarily employed for preoperative management in premenopausal patients or as postoperative adjuvant therapy to prevent recurrence. High-risk patients with potential malignancy require exclusion of malignant transformation prior to initiating medical therapy. Common medications include the levonorgestrel-releasing intrauterine system (LNG-IUS), progestins, combined oral contraceptives, and GnRH agonists.
Surgical Treatment
Surgical removal is the primary treatment modality for endometrial polyps. Decisions regarding the surgical approach depend on the size and location of the polyp, clinical symptoms, treatment objectives, and previous interventions. Surgical options include hysteroscopic polypectomy, endometrial ablation, hysterectomy, and curettage.
Hysteroscopic Polypectomy
This method is mainly indicated for premenopausal patients with symptoms, infertility, or those undergoing assisted reproductive techniques. It is also used for patients with high-risk factors for malignancy, polyps larger than 1 cm, recurrent polyps, inadequate response to medical therapy, or for postmenopausal patients.
Hysteroscopic Endometrial Ablation
This procedure may be considered for patients without fertility requirements, who experience heavy menstrual bleeding unresponsive to polypectomy or medical therapy, or those with recurrent polyps. Appropriateness for this procedure must be carefully assessed.
Hysterectomy
In cases of recurrent endometrial polyps without fertility requirements, particularly if accompanied by endometrial hyperplasia, uterine fibroids, adenomyosis, or suspicion of malignancy, hysterectomy may be performed with informed patient consent.
Curettage
Since this technique does not provide direct visualization of the endometrium, it is most commonly used when hysteroscopic equipment is unavailable or when significant bleeding limits the possibility of hysteroscopic surgery.