What is Adenomyosis?

The penetration and growth of endometrial tissue from the uterine lining into the myometrium (uterine muscle) is called adenomyosis or internal endometriosis. This disease may coexist with external endometriosis in which endometrial implants are located outside the uterus. The abnormally located endometrial tissue, like the normal endometrium, tends to bleed with the menses. The blood and debris may accumulate in these misplaced glands creating small fluid collections inside the uterine wall. This penetrating and functioning endometrial tissue may lead to swelling; the uterus may become larger and globular. Adenomyosis may present as a diffuse condition or it may be focal. In the latter, there are local areas of swelling, so-called adenomyomas, that may mimic other uterine masses.

Most commonly adenomyosis is mistaken for another common condition, uterine fibroids. There is however a fundamental difference between a fibroid (a distinct tumor) and an adenomyoma. Each fibroid originates from one abnormal cell. Under the effect of estrogen this cell multiplies. The growing tumor may displace and compress tissues but it does not invade the surrounding uterine muscle. Because of this growth pattern of fibroids, it is possible to remove all of the tumor without removing any normal uterine tissue during myomectomy (surgical removal of fibroids). In contrast, adenomyoma is not a discrete tumor but rather a local swelling of the uterine wall as a result of the penetration of endometrial tissue. Therefore it is not possible to remove tissue affected by adenomyosis without actually removing the involved uterine muscle.

What are the Symptoms of Adenomyosis?

Adenomyosis may be present and cause no symptoms. When this condition presents with symptoms the typical triad is uterine enlargement, pelvic pain, and heavy and abnormal menstrual bleeding. Pain, which is most common during menses (dysmenorrhea), may be severe cramping or knifelike. However, pain may be present at any time during the cycle and not only during the period. Uterine enlargement may be generalized with a large globular uterus or it may present as localized “tumors”. Periods may be very heavy and prolonged, with the passage of clots. Heavy bleeding may lead to anemia. Later, abnormal bleeding may be present at any time during the cycle besides the heavy periods.

The effect of adenomyosis on fertility and pregnancy is not clear. Adenomyosis may well lower fertility. The information available suggests that adenomyosis may be present in up to 17% of pregnant women over the age of 35. It is infrequently associated with obstetric or surgical complications. In most of these cases, adenomyosis was an incidental finding at cesarean section or hysterectomy. Complications reported during pregnancy include uterine rupture or perforation, placenta accreta or increta, uterine atony, or hemorrhage. A few cases of ectopic pregnancy inside the uterine wall or within an adenomyoma have been reported. Further studies are needed to determine the correlation between uterine size, the extent of adenomyosis, and the occurrence of infertility and obstetric complications. However, there is little doubt that adenomyosis is the cause of infertility in many women, especially when the condition is advanced.

How Can Adenomyosis Be Diagnosed?

Adenomyosis is frequently an incidental, clinically unsuspected finding in uteri removed for other reasons. Occasionally adenomyosis is diagnosed by a hysterosalpingogram (pelvic x-ray after filling the uterus with a contrast medium). The x-ray may show the diagnostic sign of contrast-filled spaces in the uterine wall. However, this finding is not consistently present and its extent on the x-ray may not reflect the extent of the disease. MRI (magnetic resonance imaging) has more recently proved to be an effective diagnostic modality, capable of detecting the presence and extent of adenomyosis and distinguishing it from fibroids. Pelvic MRI should be performed with the IV contrast medium Gadolinium and include contiguous 4mm sections through the uterus. High-resolution transvaginal ultrasound, in expert hands, also provides an accurate diagnosis. Overall, both MRI and ultrasound (in expert hands) detect adenomyosis in over 90% of cases.

Adenomyosis is a relatively common condition. It must be considered in the evaluation of any woman with abnormal uterine bleeding. This condition tends to be underdiagnosed, frequently resulting in an erroneous diagnosis of dysfunctional uterine bleeding. Consequently, such women may be treated with hormones or other ineffective measures, ultimately leading to hysterectomy because of failure to respond to treatment.

Is There Medical Treatment for Symptomatic Adenomyosis?

Frequently the moderately enlarged uterus is asymptomatic and no treatment is necessary. Temporary relief of very painful heavy periods can be achieved with GnRH agonists such as Lupron. These medications cause a menopause-like state with complete cessation of ovarian function and menses, causing the abnormal tissue to shrink. This temporary reversible state permits an anemic patient to restore a normal blood count, especially when iron supplements are prescribed. However, GnRH agonists are not easy to tolerate, causing menopausal symptoms such as hot flashes. Other consequences include weakening of the bones, and alteration of the cholesterol profile (decrease in “good” cholesterol, HDL, and increase in “bad” cholesterol, LDL) For these reasons, this type of medical treatment is usually limited to six months. Upon cessation of GnRH treatment, the painful heavy periods tend to resume. GnRH agonists are also used to treat infertility associated with adenomyosis. There are a few anecdotal reports of successful pregnancies after a six to eight-month course of GnRH agonists. One should be aware that such treatment may be successful in mild cases of adenomyosis but may fail in more severe cases. Progesterone is usually ineffective in the treatment of adenomyosis or, at best, is only temporarily and partially helpful. Similarly, birth control pills are ineffective or only temporarily and partially helpful. Levonorgestrel containing IUD helps relieve pain and heavy bleeding but only temporarily. Uterine volume may also decrease but then it starts to increase again.  

What is the Surgical Treatment for Adenomyosis?

Hysterectomy is currently considered by most the only effective treatment for symptomatic adenomyosis. In recent years I have successfully treated many patients with adenomyosis by surgically removing only specific areas of the uterus containing the bulk of the disease (as carefully defined by transvaginal ultrasound). In addition, I have found it helpful to surgically remove the lining of the upper portion of the uterine cavity, since this is the source of regrowth of adenomyosis and this, in effect, prevents the recurrence of adenomyosis. This is followed by reconstruction of the uterus, resulting in a near-normal-sized uterus. This results in the resolution of the pain and normal to very light periods. The drawback of this surgical treatment is that pregnancy is no longer an option. Nonetheless, patient satisfaction has been high because this more limited operation avoids all the other drawbacks of hysterectomy. (See “Why would a woman resist hysterectomy”). The story of such a patient is described in an article in the New York Times (February 18, 1997, Science Section, by Natalie Angier). Also, see case studies of women with adenomyosis in Case Studies.

Endometrial ablation is unlikely to help women with symptomatic adenomyosis. This is simply because the destruction of the endometrium does not eliminate adenomyosis, which is located much deeper in the uterine wall. Uterine artery embolization in most cases also fails to resolve the symptoms of adenomyosis. I have personally helped numerous women with the resection of adenomyosis after failed treatment with uterine artery embolization. See one such case described in the Case Studies