Endometrial polyps are common growths that originate from the inner lining of the uterus, known as the endometrium. These growths protrude into the uterine cavity and can vary significantly in size, from just a few millimeters to several centimeters. They are a frequent finding, and understanding their characteristics and potential implications is important.
Understanding Endometrial Polyps
Endometrial polyps are typically soft, fleshy outgrowths of endometrial tissue. They can be single or multiple and may be attached to the uterine wall by a slender stalk (pedunculated) or a broader base (sessile). The exact cause of their formation is not definitively known, but they appear to be influenced by hormonal factors, particularly estrogen. Endometrial tissue naturally thickens and sheds in response to fluctuating estrogen levels. This overgrowth is believed to contribute to polyp development. The prevalence of endometrial polyps ranges from approximately 7.8% to 32.9% depending on the diagnostic method and population studied. They are more common as women age, peaking in the fifth decade of life, and are rare in women under 20 years old.
Cancer Risk Associated with Endometrial Polyps
Most endometrial polyps are benign. However, a small percentage can be malignant or pre-cancerous, such as atypical hyperplasia. The likelihood of a polyp being cancerous is low; approximately 95% are benign. The risk of malignancy in women with endometrial polyps is around 1.3%, with cancers confined to a polyp found in only about 0.3% of cases.
Several factors can increase the risk of a polyp being malignant. Age is a significant factor, with postmenopausal women having a higher risk compared to premenopausal women. For instance, the risk of atypical hyperplasia or cancer in postmenopausal women with bleeding can be around 3.8%, while in premenopausal women with bleeding, it is about 1.0%. The size of the polyp may also play a role, with some studies suggesting an increased risk for polyps larger than 1.5 cm. Cellular changes, specifically atypical hyperplasia, are a known precursor to endometrial cancer. The progression risk from atypical hyperplasia to carcinoma can range from 20% to 50%, influenced by factors like obesity and prolonged unopposed estrogen exposure. Endometrial carcinoma is the primary type of cancer found within polyps.
Recognizing Symptoms and Diagnosis
Endometrial polyps often do not cause any noticeable symptoms, especially if they are small or if there is only one. When symptoms do occur, they commonly involve abnormal uterine bleeding. This can manifest as bleeding between menstrual periods, unusually heavy menstrual periods (menorrhagia), or vaginal spotting.
Postmenopausal bleeding is also a symptom that warrants medical attention. Some individuals may experience an unusual appearance of brown blood after a menstrual period or bleeding after sexual intercourse. While less common, severe menstrual cramping can also occur.
If endometrial polyps are suspected based on symptoms, several diagnostic methods can be used. Transvaginal ultrasound is often the initial imaging technique, creating images of the uterine lining. If the ultrasound findings are unclear, a sonohysterography may be performed. This involves injecting sterile saline into the uterus to expand the cavity, providing clearer images of the inner lining during an ultrasound.
Hysteroscopy is the gold standard for both diagnosis and often removal. This minimally invasive procedure involves inserting a thin, lighted tube with a camera through the vagina and cervix into the uterus, allowing direct visualization of the polyps and enabling a biopsy for tissue analysis. In some cases, an endometrial biopsy may also be performed for laboratory testing.
Treatment and Follow-Up
The management of endometrial polyps often involves their removal, particularly if they are causing symptoms, are large, or raise suspicion for malignancy. Hysteroscopic polypectomy is considered the standard surgical procedure for removal. This procedure allows for direct visualization of the polyp within the uterus and its complete excision. Small, asymptomatic polyps, especially in premenopausal women, may be monitored without immediate intervention, as some can regress on their own. However, polyps in postmenopausal women are recommended for removal due to the higher risk of malignancy.
Following the removal of the polyp, the tissue is sent for pathological examination. This analysis is important to confirm the benign nature of the polyp or to identify any cancerous or pre-cancerous cells, such as atypical hyperplasia.
Post-procedure care involves a quick recovery, with many individuals returning to normal activities within a few days. Recurrence of endometrial polyps is possible. Follow-up appointments may be recommended to monitor for new polyp formation.