Definition

The endometrium is the lining of the inside of the womb (uterus). Overgrowth of this lining can create polyps. Polyps are fingerlike growths that attach to the wall of the uterus. They can be as small as a sesame seed or larger than a golf ball. There may be just one or many polyps.

Alternative Names

Uterine polyps; Uterine bleeding - polyps; Vaginal bleeding - polyps

Causes

The exact cause of endometrial polyps in women is not known. They tend to grow when there is more of the hormone estrogen in the body.

Most endometrial polyps are not cancerous but they can be cancerous or precancerous. The chance of cancer is higher if you are postmenopausal, on tamoxifen, or have heavy or irregular periods.

Other factors that may increase the risk for endometrial polyps are:

• Obesity
• Tamoxifen, a treatment for breast cancer
• Postmenopausal hormone replacement therapy
• Family history of Lynch syndrome or Cowden syndrome (genetic conditions that run in families)

Endometrial polyps are common in women between 20 to 40 years of age.

Symptoms

You may not have any symptoms of endometrial polyps. If you do have symptoms, they may include:

• Menstrual bleeding that is not regular or predictable
• Long or heavy menstrual bleeding
• Bleeding between periods
• Bleeding from the vagina after menopause
• Trouble getting or staying pregnant (infertility)

Exams and Tests

Your health care provider may perform these tests to find out if you have endometrial polyps:

• Transvaginal ultrasound
• Hysteroscopy
• Endometrial biopsy
• Hysterosonogram: a specialized type of ultrasound in which fluid is put into the uterine cavity while an ultrasound is performed
• Three-dimensional ultrasound

Treatment

Many polyps should be removed because of the small risk for cancer.

Endometrial polyps are most often removed by a procedure called hysteroscopy. Sometimes, a D and C procedure (Dilation and Curettage) can be done to biopsy the endometrium and remove the polyp. This is less commonly used.

Postmenopausal women who have polyps that are not causing symptoms may also consider watchful waiting. However, the polyp should be removed if it is causing vaginal bleeding.

Outlook (Prognosis)

In rare cases, polyps can return after treatment.

Possible Complications

Endometrial polyps may make it hard to get or stay pregnant.

When to Contact a Medical Professional

Contact your provider if you have:

• Menstrual bleeding that is not regular or predictable
• Long or heavy menstrual bleeding
• Bleeding between periods
• Bleeding from the vagina after menopause

Prevention

You cannot prevent endometrial polyps.

References

Bulun SE. Physiology and pathology of the female reproductive axis. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 17.

Dolan MS, Hill CC, Valea FA. Benign gynecologic lesions: vulva, vagina, cervix, uterus, oviduct, ovary, ultrasound imaging of pelvic structures. In: Gershenson DM, Lentz GM, Valea FA, Lobo RA, eds. Comprehensive Gynecology. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 18.

Gilks B. Uterus: corpus. In: Goldblum JR, Lamps LW, McKenney JK, Myers JL, eds. Rosai and Ackerman's Surgical Pathology. 11th ed. Philadelphia, PA: Elsevier; 2018:chap 33.