Adenomyosis: Overview

Alternative Names: Internal endometriosis.

Adenomyosis is a benign disease of the uterus in which endometrial tissue, which normally lines the uterus, extends outward into the fibrous and muscular tissue of the uterus (the myometrium).  When the endometrial tissue bleeds during menstruation, the old tissue and blood cannot get out of the muscle and flow out of the cervix as part of normal menses.  Blood and debris are thus trapped inside the uterine wall, causing swelling of the uterus, severe cramps and bleeding.

Incidence; Causes and Development

While some studies estimate that 20% of women have adenomyosis, the exact rate of incidence of adenomyosis is unknown because a diagnosis can be made only after a pathologist examines uterine wall samples obtained during surgery or biopsy.

More than 80% of women with adenomyosis have other uterine disorders as well.  Some 50% have associated fibroids (benign smooth muscle tumors of the uterus); approximately 11% have endometriosis (endometrial tissue outside of the uterus); and 7% have endometrial polyps (benign outgrowths of endometrial tissue).  The symptoms of these often obscure the diagnosis of adenomyosis.

The cause of adenomyosis is not known.  One popular theory suggests that the barrier between the endometrium and the myometrium, which normally prevents invasion of endometrial glands into the myometrium, is compromised, allowing invasion to occur.  Other reports have shown that the frequency of adenomyosis is greater in patients who have undergone cesarean sections, tubal ligations and pregnancy terminations.

Signs and Symptoms

About 50% of women with adenomyosis do not show symptoms; some women experience heavier bleeding and increased cramping as the condition worsens.  Patients who do have symptoms usually experience uterine enlargement, pelvic pain, abnormal uterine bleeding and heavy menstrual bleeding.  The uterus is usually boggy and uniformly enlarged; pain is most common during menstruation and occurs in 25% of cases; and 60% of patients have prolonged or heavy menstrual bleeding, with passage of clots.

Diagnosis and Tests

Adenomyosis is difficult to diagnose.  For one, many patients are asymptomatic, but even when women have symptoms, it is either mistaken for another common condition, such as uterine fibroids, or overshadowed by an associated condition, such as endometriosis.  Until recently, diagnoses were often made incidentally after the uterus had been removed for other reasons.  Diagnostic tools include an abdominal X-ray that is taken after ingestion of contrast (a dyelike material that is visible on X-ray); MRI with contrast medium that can often distinguish adenomyosis from fibroids (although its cost precludes its routine use); and a transvaginal ultrasound, which can provide an accurate diagnosis but, like MRI, can also yield false positives especially in the presence of fibroids.

Treatment and Prevention

Treatment is determined by the extent to which the adenomyosis is causing symptoms.  If pain is manageable, often no treatment is prescribed and a patient takes pain medication and/or birth control pills for the temporary relief of menstrual discomfort.  If symptoms are severe, however, hysterectomy is considered the most effective treatment, especially if a woman is not approaching menopause soon (symptoms of adenomyosis generally decrease with menopause).  Gonadotropin-releasing agents such as Lupron have also been used to treat adenomyosis, causing a decrease in uterine size and cessation of menstruation; however, adenomyosis seems to recur after discontinuing the therapy.


Information On This Page

Conditions that suggest Adenomyosis:


Pregnancy-Related Issues may suggest AdenomyosisPregnancy-Related Issues
Approximately 80% of women with adenomyosis have given birth, but the incidence of adenomyosis does not correlate with increasing numbers of pregnancies.
Pregnancy-Related Issues may contraindicate AdenomyosisPregnancy-Related Issues
Approximately 80% of women with adenomyosis have given birth, but the incidence of adenomyosis does not correlate with increasing numbers of pregnancies.

Adenomyosis can lead to:



Weak or unproven link: may suggest
Weak or unproven link:
may suggest
Definite or direct link: usually leads to
Definite or direct link:
usually leads to
Weakly counter-indicative: may contraindicate
Weakly counter-indicative:
may contraindicate