Uterine polyps, also referred to as endometrial polyps, are growths that develop from the inner lining of the uterus, known as the endometrium. These growths form when there is an overgrowth of endometrial tissue, attaching to the uterine wall by a broad base or a thin stalk and extending into the uterine cavity. They can range significantly in size, from a few millimeters to several centimeters. The presence of these growths is considered one of the most common benign gynecological conditions.
Prevalence and Contributing Factors
Uterine polyps are common, with estimates suggesting they affect up to 30% of individuals with a uterus at some point in their lives. The prevalence is notably higher in certain demographics, peaking around the perimenopausal period, with the highest incidence typically found in women in their 40s and 50s.
The primary underlying mechanism for polyp formation is thought to be an excessive response to estrogen, as these growths are estrogen-sensitive. This hormonal influence causes the endometrial tissue to multiply excessively instead of fully shedding during the menstrual cycle. Risk factors that elevate circulating estrogen levels can increase the likelihood of developing polyps, such as obesity, where fat cells produce higher amounts of estrogen.
Specific medications can also act as contributing factors to polyp development. For instance, women taking Tamoxifen, a drug used in breast cancer treatment, have a significantly increased risk of developing uterine polyps. Tamoxifen’s anti-estrogen effects on breast tissue contrast with its estrogen-like effects on the endometrium, which can promote this overgrowth. High blood pressure is another factor associated with a greater chance of developing these growths.
Recognizing the Signs
The presence of uterine polyps often manifests through abnormal uterine bleeding, which is the most common symptom experienced by patients. Abnormal uterine bleeding (AUB) covers a range of irregularities, including bleeding or spotting that occurs between expected menstrual periods (intermenstrual spotting). Individuals may also notice their normal menstrual flow has become unusually heavy or prolonged (heavy menstrual bleeding). For those who have completed menopause, any unexpected vaginal bleeding or spotting should be reported to a healthcare provider, as polyps are a frequent cause of postmenopausal bleeding. Less common symptoms may include an unusual vaginal discharge or difficulty becoming pregnant, as polyps can interfere with the uterine environment necessary for embryo implantation.
Diagnosis and Removal Procedures
Initial investigation into abnormal bleeding often begins with a transvaginal ultrasound, where a slender probe is inserted to visualize the uterus and its lining. This imaging can reveal a thickened endometrial lining or a mass suggestive of a polyp. To gain a clearer, more definitive view, a procedure called saline infusion sonohysterography (SIS) is frequently performed. This involves injecting sterile saline into the uterus through a thin catheter, which gently expands the uterine cavity and outlines any growths against the fluid, making polyps much easier to identify.
The standard course of action for symptomatic polyps, or those found in postmenopausal women, is removal. Hysteroscopic polypectomy is considered the gold standard for both confirming the diagnosis and providing treatment. This minimally invasive surgical procedure involves inserting a thin, lighted telescope, called a hysteroscope, through the vagina and cervix into the uterus. The hysteroscope allows the surgeon to directly visualize the polyp and use specialized instruments to precisely remove it.
Removal is generally recommended to alleviate the disruptive symptoms of abnormal bleeding and to ensure the growth can be sent for pathology testing. The tissue sample is microscopically analyzed to confirm the polyp is benign and to check for any signs of precancerous or cancerous cells. This procedure is highly effective, often performed in an outpatient setting, and typically results in a quick recovery.
Malignancy Concerns
The vast majority of uterine polyps are benign growths. However, a small percentage may contain atypical hyperplasia or, less commonly, malignant cells. The overall prevalence of cancer within a polyp is low, estimated to be around 2.73% of all polyps.
The risk of a polyp harboring malignancy is significantly influenced by a woman’s menopausal status. For premenopausal women, the risk is quite low, generally estimated to be about 1 to 2%. This risk increases for postmenopausal women, where the rate of malignancy found in a polyp is higher, ranging between 5 and 6%.
This is why removal and subsequent tissue analysis are important steps, particularly for postmenopausal individuals or those with other risk factors. Even though the risk is low, the potential for malignancy is why any abnormal bleeding, especially after menopause, should prompt a medical evaluation and often the removal of the polyp.