What is adenomyosis?

What is adenomyosis?  

Adenomyosis is often confused with endometriosis. 

It is a gynaecological condition that affects the inner muscular wall of the uterus, the myometrium. The junction between the myometrium and the endometrium is abnormal. The cells of the mucous membrane infiltrate and thicken the myometrium, and cause lesions and microcysts.

Adenomyosis can be superficial, up to 12mm, or deep and painful. It may or may not be related to endometriosis. Thus, adenomyosis can sometimes be the reason for persistent pain despite complete surgical removal of all endometriosis lesions.

It is estimated that 6 to 11% of the female population is affected by adenomyosis. The figures are quite difficult to estimate because, just like endometriosis, adenomyosis is not always pathological, i.e. it is only considered a disease when it causes pain or infertility. As a result, the real prevalence and incidence of adenomyosis in the general population is unknown, and a hysterectomy is necessary to establish a definite diagnosis.

There are several forms of adenomyosis depending on the spread of the endometrial cells: 

• Diffuse adenomyosis: numerous infectious foci spread over the entire myometrium, 
• Focal adenomyosis: one or a few foci located in the myometrium, 
  
• External adenomyosis: related to pelvic or deep subperitoneal endometriosis.
  

Some women are more prone to adenomyosis: those with endometrial hyperplasia (excessive growth of endometrial cells), women who have had several pregnancies and are in their forties, and women who have had placental abnormalities.

What are the symptoms of adenomyosis?  

Adenomyosis can occur in women as early as puberty with few apparent symptoms. It can also be asymptomatic.

The symptoms of adenomyosis are similar to those of endometriosis. They may include: 

• Dysmenorrhoea: pain related to menstrual cycles,
  
• Dyspareunia: pain during sexual intercourse,
  
• Menorrhagia: heavy periods that last longer than 7 days, 
  
• Metrorrhagia: bleeding in between menstrual periods, 
  
• Enlarged uterus,
  
• Pelvic heaviness or a feeling of pressure on the bladder and rectum,
  
• Fertility problems.
  

How can adenomyosis be diagnosed?  

A definite diagnosis of adenomyosis requires histological analysis, i.e. a microscopic study of the tissues. However, this can only be done following a hysterectomy, which is not possible in women who are planning a pregnancy. 

Nevertheless, other techniques are now sufficiently accurate to diagnose adenomyosis: pelvic ultrasound and pelvic MRI. 

Ultrasound, which is often performed endovaginally, can detect signs of adenomyosis such as the size of the uterus, its asymmetric wall and/or inflammation and thickening of the myometrium. 

MRI, which is performed outside of menstrual period, is a second-line examination used to confirm the signs observed via ultrasound.

How is adenomyosis treated?  

The management of adenomyosis is symptomatic and aims to improve the patient's quality of life.

Treatment options should be discussed with the doctor. They generally include drug treatment, but surgery may also be considered, as a last resort.

The choice of treatment depends mostly on the symptoms and the extent of the lesions, but also on the patient's age and pregnancy plans.

Drug treatment

• Painkillers and NSAIDs (non-steroidal anti-inflammatory drugs) to ease the pain,
  
• Hormonal contraception, which may be a suitable continuous progestin-only pill or a levonorgestrel-based intrauterine device (IUD) or another IUD prescribed for up to 3 years. Hormonal contraception aims to suppress menstruation, causing endometrial atrophy,
  
• Artificial menopause, temporary and chemically induced by taking GnRH (gonadotropin-releasing hormone) agonists that will stop menstruation and reduce pain. In order to alleviate side effects, it is combined with add-back therapy, which consists of reintroducing a little oestrogen. Artificial menopause (GnRH agonist + add-back therapy) aims to reduce uterine volume, thickening of the junctional zone and thus the symptoms of adenomyosis,
  
• GnRH antagonists (anti-gonadotropic) act as an inhibitor of the production of steroidal sex hormones and thereby lead to endometrial atrophy, treating pain during or in-between periods,
  
• Uterine fibroid embolisation, a minimally invasive radiological procedure performed by an interventional radiologist, to treat symptoms related to adenomyosis, without the need to remove the uterus.

Surgery

• Endometrectomy, or endometrial resection, is a conservative surgical treatment which consists of removing all or part of the endometrium, and which helps reduce bleeding. This allows the uterus to be preserved and is therefore compatible with the desire for pregnancy.
  
• Hysterectomy is the removal of the uterus. It is a radical surgical treatment in the case of severe symptoms, when the infiltrations in the wall of the uterus are significant and cause a lot of pain and bleeding, and after failure of drug treatments in patients who no longer wish to become pregnant.
  
  

Today, there is no way to prevent adenomyosis since the exact causes of this condition are not known. Research is underway to determine what causes the disease.