Definition

Adenomyosis is a thickening of the walls of the uterus. It occurs when endometrial tissue grows into the outer muscular walls of the uterus. Endometrial tissue forms the lining of the uterus.

Alternative Names

Endometriosis interna; Adenomyoma; Pelvic pain - adenomyosis

Causes

The cause is not known. Sometimes, adenomyosis may cause the uterus to grow in size.

The condition most often occurs in women ages 35 to 50 who have had at least one pregnancy.

Symptoms

In many cases, there are no symptoms. When symptoms occur, they can include:

• Long-term or heavy menstrual bleeding
• Painful menstrual periods, which gets worse
• Pelvic pain during intercourse

Exams and Tests

The health care provider will make the diagnosis if a woman has symptoms of adenomyosis that are not caused by other gynecologic problems. The only way to confirm the diagnosis is by examining the tissue of the uterus after a surgery to remove it.

During a pelvic exam, the provider may find a soft and slightly enlarged uterus. The exam may also reveal a uterine mass or uterine tenderness.

An ultrasound of the uterus may be done. However, it may not give a clear diagnosis of adenomyosis. An MRI can help distinguish this condition from other uterine tumors. It is often used when an ultrasound exam does not provide sufficient information to make a diagnosis.

Treatment

Most women have some adenomyosis as they get close to menopause. However, only a few will have symptoms. Most women do not need treatment.

Birth control pills and an IUD that has progesterone can help decrease heavy bleeding. Medicines such as ibuprofen or naproxen can also help manage pain.

Surgery to remove the uterus (hysterectomy) may be done in women with severe symptoms.

Outlook (Prognosis)

Symptoms most often go away after menopause. Surgery to remove the uterus often gets you rid of symptoms completely.

When to Contact a Medical Professional

Contact your provider if you develop symptoms of adenomyosis.

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.

Gambone JC. Endometriosis and adenomyosis. In: Hacker NF, Gambone JC, Hobel CJ, eds. Hacker & Moore's Essentials of Obstetrics and Gynecology. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 25.

Wei PK, Savicke AM, Levine D. The uterus. In: Rumack CM, Levine D, eds. Diagnostic Ultrasound. 6th ed. Philadelphia, PA: Elsevier; 2024:chap 28.