What is adenomyosis?
Adenomyosis is a benign uterine disorder, which is often referred to as the “sister disease” of endometriosis. In adenomyosis, the tissue lining the uterus (endometrial tissue) grows into the muscle layer of the uterine wall, also known as the myometrium. This leads to an enlarged uterus and painful, heavy periods.
What is the difference between adenomyosis and endometriosis?
Endometriosis is the growth of endometrial tissue outside the uterus, such as the pelvic cavity, ovaries, fallopian tubes, or bowels. This extraneous endometrial tissue behaves in a similar manner as the normal endometrium including responding to female hormones. However, it has no possibility of outside passage or drainage during each menstrual cycle.
In adenomyosis, the endometrial tissue grows into the uterine wall and remains within the uterus itself. This tissue also responds to monthly menstrual cycles and has an impact on overall quality-of-life often overlapping with that of endometriosis. About 50% of patients also have endometriosis, but there’s currently no evidence that one condition causes the other.
What causes adenomyosis?
So far, a definitive cause for adenomyosis has not been established. However, there are several theories including:
- Inflammation to the uterine lining during uterine surgery or childbirth
- Vaginal or tissue injury resulting in the increased immune response to the myometrium
- Movement of migratory tissue into the myometrium
- Build up of excess myometrial tissue
- Stimulation due to hormones
What are the symptoms?
Symptoms of adenomyosis include heavy menstrual bleeding including clots (menorrhagia), severe cramping and pelvic pain (dysmenorrhea), and painful intercourse (dyspareunia). Patients may also experience painful bowel movements, peripheral nerve weakness, inflammation of the uterus, and hemoglobin deficiency.
How do doctors diagnose it?
Adenomyosis is a complex disorder to diagnose. It can be diagnosed by the aforementioned symptoms and on the basis of several tests including histological examination and imaging techniques such as magnetic resonance imaging (MRI) and transvaginal ultrasonography. A pelvic exam also helps in understanding if there are any changes in the shape and consistency of the uterus.
A histological examination (or pathology sample) is the gold standard for confirming adenomyosis. However, this is possible only after completely removing the uterus (hysterectomy) and there is currently no uniform criteria among pathologists regarding the extent of invasion of endometrial tissue to fully ascertain adenomyosis.
MRI or transvaginal ultrasound provides a non-invasive method to make an initial diagnosis, although it is not as sensitive as histologic examination. Apart from these, minimally invasive techniques such as hysteroscopy, laparoscopy, and cystoscopy can also help diagnose adenomyosis. However, this cannot make the diagnosis with as much certainty as a histological examination.
Why is early diagnosis important?
Adenomyosis is a persistent and progressive disease that usually affects women who have given birth, but it can also make conceiving the first time or subsequent times very difficult. Pregnant women who have adenomyosis run the risk for miscarriages or premature labor. Therefore, an early diagnosis is important in order to plan for and manage complications arising from the first or subsequent pregnancies.
What are the differences in diagnosing adenomyosis vs. endometriosis?
Diagnosis of endometriosis and adenomyosis use similar approaches, which include imaging techniques such as MRI and ultrasonography. Endometriosis lesions can be visualized using techniques such as laparoscopy and confirmed by biopsy of samples obtained via laparoscopic excision surgery. For adenomyosis, obtaining samples for biopsy often requires hysterectomy as the lesions are within the uterus itself.
However, modern imaging techniques such as TVUS or MRI can help in visualizing a distinct zone within the inner uterine wall called the junctional zone (JZ), whose morphological changes can provide insights into adenomyosis not possible with traditional biopsy. However, the JZ enlargement may not be due to the condition per se and can occur due to factors such as age or other complications such as fibroids.
What are some of the risk factors?
There are several risk factors that can contribute to the onset of adenomyosis. These include older reproductive age, uterine fibroids, history of dilation and curettage (D&C), history of ectopic pregnancy, and endometriosis. The disease usually occurs in women between 35 to 50 years of age, though it can affect adolescents as well.
Can adenomyosis lead to infertility?
Researchers do not yet know whether adenomyosis by itself can lead to infertility. However, infertility is one of the possible clinical presentations of the condition. Since it affects the ability to have children after the first child and is often occurs together with endometriosis, infertility treatments may be necessary. Research has shown that adenomyosis can result in up to 50% higher risk of miscarriage, up to 24.4% risk of premature delivery, and up to 12% risk of delayed fetal development.
Can adenomyosis co-exist with other gynecological conditions?
Yes. About 27% to 70% of women with endometriosis also have adenomyosis. In about 15% to 57% of cases, uterine fibroids co-exist with adenomyosis. Apart from gynecological co-morbidities, adenomyosis patients also show signs of anemia
What are the available treatment options?
There are no specific drugs available for the treatment of adenomyosis. Drugs that doctors prescribe for endometriosis patients are often available in case of adenomyosis as well. The mode of treatment depends on the severity of the symptoms.
Laparoscopic deep excisional adenomyosis surgery can help in preventing total uterus removal, though it requires advanced surgical skill in ensuring that women can sustain future pregnancies. However, there is no evidence to fully support minimally invasive or conservative surgical procedures for the treatment of adenomyosis. Hysterectomy or partial hysterectomy is the last resort if disease progression is severe and debilitating.
Can adenomyosis be managed non-surgically?
Yes. Nonsteroidal anti-inflammatory drugs (NSAIDs) can help manage pain symptoms. Hormonal birth control pills (combined and progestin-only pills) or intra-uterine devices (IUDs) can stop, delay, and/or minimize menstrual bleeding. Symptoms of adenomyosis will also usually disappear after menopause but can worsen leading up to menopause.
A 2017 randomized clinical trial involving dienogest (DNG) in 67 adenomyosis patients in Japan has shown that progestin treatments can also be effective in reducing pain. Similarly, a levonorgestrel-releasing intrauterine system (LNG-IUS) can also alleviate dysmenorrhea symptoms.