Endometrial polyps are common growths that develop from an overgrowth of tissue lining the inside of the uterus, known as the endometrium. This condition frequently occurs, especially as women approach and navigate the menopausal transition. When a growth is discovered, the possibility of cancer is a primary concern. This article provides clear, evidence-based information addressing the risk of malignancy associated with these uterine growths.
Understanding Endometrial Polyps
Endometrial polyps are fleshy, finger-like masses that extend into the uterine cavity. They typically attach to the inner wall of the uterus either by a thin stalk (pedunculated) or by a broader, flat base (sessile). These growths can vary significantly in size, ranging from a few millimeters up to several centimeters.
The presence of these polyps often causes no noticeable symptoms, and they may be discovered incidentally during imaging for other issues. When symptoms do occur, they are most commonly related to abnormal uterine bleeding (AUB). This bleeding can manifest as irregular menstrual periods, spotting between cycles, or unusually heavy flow. For postmenopausal women, any vaginal bleeding or spotting frequently leads to the discovery of a polyp.
Assessing Malignancy Risk
The vast majority of endometrial polyps, approximately 95% or more, are noncancerous (benign). The overall risk of a polyp being malignant is low, typically reported to be around 1% to 5% of all cases. The primary reason for evaluating and often removing these growths is the small chance that they contain cancerous or pre-cancerous cells.
The likelihood of malignancy is strongly influenced by a woman’s age and menopausal status. For premenopausal women, the risk of cancer is extremely low, with some studies showing it around 1.3%. This risk increases significantly for postmenopausal women, particularly those experiencing abnormal vaginal bleeding. In women over 65, the rate of malignancy found within a polyp can increase substantially.
Beyond fully developed endometrial carcinoma, polyps may also contain cells showing signs of endometrial hyperplasia. Hyperplasia refers to an overgrowth of the endometrial lining that can sometimes precede cancer, especially if it involves cellular changes known as atypia. Tissue analysis after removal is important for evaluating this entire spectrum—from benign growth to hyperplasia to carcinoma.
Diagnostic Procedures and Evaluation
The initial step in evaluating a suspected endometrial polyp is typically an imaging test, such as a transvaginal ultrasound. This procedure involves inserting a device into the vagina to create an image of the uterus and its lining. A subsequent test, called saline infusion sonography (SIS), often provides a clearer picture. During SIS, a sterile saline solution is gently instilled into the uterine cavity, which helps expand the space and clearly outline the polyp against the fluid on the ultrasound screen.
While imaging can identify the presence, size, and location of a growth, it cannot definitively determine whether a polyp is benign or malignant. For a confirmed diagnosis, tissue analysis is required, usually obtained during a hysteroscopy. Hysteroscopy involves inserting a thin, lighted telescope (hysteroscope) through the cervix into the uterus, allowing the clinician to visualize the polyp directly.
The definitive procedure is a hysteroscopic polypectomy, where the polyp is removed under direct visualization. Once the polyp is excised, the tissue is sent to a pathology lab for microscopic examination. This tissue analysis is the only way to confirm the exact cellular composition of the growth and rule out the presence of hyperplasia or cancer.
Management and Treatment Options
Hysteroscopic polypectomy is considered the standard treatment for removing endometrial polyps. This minimally invasive surgical procedure involves using specialized instruments passed through the hysteroscope to cut the polyp away from the uterine wall. Removal is often recommended even for polyps presumed to be benign, including resolving symptoms like abnormal bleeding and ensuring that no malignancy was missed.
For symptomatic polyps, removal typically leads to an improvement in symptoms. The ability to visualize the uterine cavity during hysteroscopy allows for complete removal of the polyp and its base, which can help prevent recurrence. In cases where symptoms are absent, particularly in premenopausal women with small polyps, a conservative management approach with periodic monitoring may be considered.
For high-risk patients, such as postmenopausal women with bleeding or those with multiple risk factors, surgical removal is strongly recommended. After the procedure, the pathology report guides any further post-treatment management. If the tissue analysis confirms the polyp is noncancerous, no further treatment is usually necessary, though a small chance of new polyps forming exists.