Uterine Adenomyosis Versus Pelvic Endometriosis

Adenomyosis is a condition that only involves the uterus itself. Uterine adenomyosis is a condition where endometrial glands, which is the layer of tissue that is shed with your period, are located in the muscle layer of the uterus called the myometrium. This glandular tissue, which is also present with its supporting tissue called stroma, enlarges the uterus and results in a number of symptoms, which will be outlined below. The peak incidence of adenomyosis is in women in their 40’s and 50’s. As a condition, it differs both in its cause, its effects and its pathology when compared with endometriosis.

Endometriosis is a situation where endometrial-like tissue or similar tissues that are located in the myometrium with adenomyosis are instead located outside the uterus, especially in the area between the uterus and the bowel called the pouch of Douglas. It can also be associated with deep infiltration of organs such as the ovaries, the pelvic sidewall, the bowel and even the bladder.

Therefore although adenomyosis and endometriosis are similar in that the tissue that is located in adenomyosis (within the muscle of the uterus) and endometriosis (in the pelvis itself) are similar, the symptoms may vary and the actual location of the disease varies significantly. Similarly in the case of endometriosis, the peak age incidence is in younger women, often women in their 20’s or early 30’s.

Endometriosis is a not uncommon cause of pelvic pain and difficulties achieving a pregnancy. As mentioned above, cells which are similar to the lining cells of the uterus called the endometrium are located outside the uterus. This results in inflammation causing symptoms particularly pelvic pain and as stated above, endometriosis is especially located on the ligaments on the back of the uterus, in the pouch of Douglas which is the space between the uterus and the bowel, the pelvic sidewalls and over the bladder. Rarely endometriosis can be located in positions outside the pelvis such as under the diaphragm or even involve organs such as the liver. These extra pelvic locations although possible are rare.

Therefore endometriosis and adenomyosis affect different age groups, have a different pathology, although the tissue involved looks particularly similar, and have different but overlapping consequences.

Symptoms of adenomyosis and endometriosis

The primary symptom associated with adenomyosis is menorrhagia or heavy periods.  Because the uterus is enlarged and sensitive, it is also possible for it to be associated with  pelvic pain as well as pain with intercourse as the sensitive uterus is moved during  intercourse. Adenomyosis is also associated with an increased risk of miscarriage and also  problems conceiving.  

Endometriosis on the other hand, is primarily associated with pain especially due to  inflammation from the endometriotic lesions as well as structures adhering to one another  and the presence of adhesions or scar tissue resulting from the inflammation. Endometriosis  is also associated with infertility but to a greater degree than adenomyosis. Both of these  conditions can significantly affect the patient’s quality of life. The bleeding with  adenomyosis usually becomes worse as the patient becomes older, can be severe, in the  case of endometriosis, the pelvic pain can be debilitating.  

In some women who have either adenomyosis or endometriosis there can be no symptoms  at all and the diagnosis is made on either ultrasound or because the patient’s pelvis is  visualised such as at a caesarean section.  

The exact cause of adenomyosis is unknown. There are a number of theories as to what may cause these rests or areas of glandular and supporting tissue that develop within the muscle layer or myometrium of the uterus. These theories include genetically placed glandular tissue, trauma causing the endometrium to be pushed into the myometrium, the lack of a good supporting layer underneath the endometrium (this layer separates the endometrium from the myometrium and prevents an invasion of glandular tissue into the muscle layer). Basically however, the exact cause is unknown. We do know that oestrogen and to a lesser extent progesterone hormone appear to be upregulated or more active in patients with adenomyosis. There have been a number of animal studies that have shown that adenomyotic tissue becomes more active and enlarges in the presence of oestrogen hormone. It is also known that adenomyotic tissue becomes less active and resolves after the menopause when there is no oestrogen stimulation.

The cause of endometriosis is also unknown. There are numerous theories as to the cause of endometriosis including backflow of menstrual blood through the fallopian tubes allowing endometriotic tissue to implant into the pelvis. There is also the theory that tissue that is going to become endometriosis is laid down in women when they are a foetus. There is also the theory of what we call metaplasia or changing of one tissue type into another tissue type. There are numerous other theories to explain endometriosis and for that reason, endometriosis is often called the “disease of theories”. However, we are not certain as to the exact cause of endometriosis.

The diagnosis of adenomyosis and endometriosis has been improved, especially over the last decade because of refinements in both ultrasound and MRI modalities. Adenomyosis has a particular appearance on ultrasound and on MRI examination which is classical for this condition. Sometimes it is thought to exist because the uterus feels enlarged and boggy and the symptoms fit with the diagnosis of adenomyosis. Sometimes the diagnosis is made after hysterectomy when the uterus is examined by a pathologist.

The real challenge is in diagnosing endometriosis when there is no deep infiltration (DIE of organs) and only superficial smaller deposits. The ultrasound has always been the gold standard with respect to radiological diagnosis. There are a number of gynaecological ultrasound groups that specialise in the diagnosis of endometriosis. Deposits may be visualised on the ovary (endometriomas). Nodules may be visualised on the ligaments on the back of the uterus called the uterosacral ligaments. There may be evidence of scar tissue binding organs together and for example, it may not be possible for the uterus and bowel to slide over one another due to the presence of these adhesions associated with the inflammation caused by endometriosis. MRI diagnosis may be helpful, especially in elucidating adhesions between different organs.

The definitive way to diagnose endometriosis is to perform a surgical procedure called a laparoscopy where a telescope is inserted through the navel and the actual organs can be visualised. Deposits of endometriosis have a classical appearance, and it is possible to excise these deposits or in the case of superficial small deposits they can be lasered or burnt off. Organs that are adherent to one another can be gently separated and adhesions can be divided. The real problem is where a patient has deep infiltrative endometriosis, especially involving the large bowel, particularly the rectum.

In cases involving adenomyosis, the main symptom as mentioned is menorrhagia or heavy periods. This can be treated ideally with the use of a Mirena or a progesterone releasing  IUD. This has been shown to be particularly effective with adenomyosis and also over time  helps to prevent ongoing worsening of the condition. Tranexamic acid (TXA) has been  shown to reduce the amount of blood loss if taken at the time of bleeding. It is not a  hormone and has few if any side effects. The chance of TXA reducing the blood loss to an  acceptable level is about 85%.  

Other treatment options include the use of hormonal treatment to reduce bleeding, the use  of uterine artery embolisation which blocks off the blood supply or reduces the blood supply  to the uterus, uterine endometrial ablation where the lining of the uterus is burnt off  altogether and finally where simple treatments do not appear to be effective hysterectomy  may need to be considered. 

As mentioned previously, the treatment of endometriosis involves laparoscopic surgery with  excision or ablation of endometriotic tissue or there are a number of progesterone  hormones which have been shown to especially assist in the treatment of superficial or  small deposit disease and these hormones also reduce symptoms such as pelvic pain.  Progesterone hormones can have side effects especially bloating, breast soreness, mood  changes and irregular bleeding.  

What to expect: living with adenomyosis or endometriosis

The short-term management is usually successful with both adenomyosis and endometriosis. Adenomyosis usually comes under control with the use of Mirena IUDs or other forms of hormonal treatment. Long term menorrhagia which does not readily respond to conservative treatment may require hysterectomy, especially if the symptoms are debilitating and the patient is requiring iron infusions.

The short- and long-term effects of endometriosis revolve around the treatment and management of the disease, but especially the management of pelvic pain. Endometriosis is associated often with debilitating pain which interferes with a woman’s lifestyle and ability to conceive and may interfere with her work. The use of analgesics may be beneficial, especially anti-inflammatory medication as the pain is especially due to inflammation associated with endometriosis. However, this only treats the symptoms and not the underlying disease. Laparoscopic surgery as mentioned may be a way of eradicating most of the disease but there can be a significant recurrence risk, and it may be necessary for patients to have repeat surgery over a period of time. Hormonal treatment as mentioned can have side effects and even the pill taken continuously to prevent periods has shown to be effective and there are now natural oestrogen-based pills which have a lower side effect profile. The use of progesterone hormone including a number of new drugs has shown to be particularly helpful in controlling symptoms associated with endometriosis.

Summary

In summary, endometriosis and adenomyosis are both diseases associated with significant pelvic symptoms. However, they are diseases that although they may have similar symptoms have different aetiologies and affect different parts of the pelvis. Therefore, it is not surprising that their treatment is different in controlling significant symptoms that are present.  

Both of these conditions require a careful history, a careful examination and expert radiological assessment by radiologists that are experienced in the assessment of the female pelvis. Because of the significance of the symptoms associated with these conditions, it is important that they are not ignored, that they are diagnosed adequately and the numerous treatment options available for both conditions are explained in detail to the patient, including any potential side effects.