Adenomyosis: causes, symptoms, diagnosis, and treatment

Medically reviewed by Andrew HorneProfessor of Gynaecology and Reproductive Sciences at Edinburgh University’s MRC Centre for Reproductive Health.

What is adenomyosis?

Adenomyosis occurs when tissue similar to the endometrium is found in the muscle of the wall of the uterus. Adenomyosis is a menstrual health condition that is distinct from endometriosis, although the incidence of endometriosis existing in patients with adenomyosis is estimated to be up to 80%[1]. Much like endometriosis, it is a poorly understood condition and people often struggle to secure a diagnosis. 

Who does it affect?

Adenomyosis can affect women of all ages, including young women under the age of 17, and those assigned female at birth (AFAB). It is believed that adenomyosis can affect up to two-thirds of women, but the exact number of individuals affected is unknown due to the prevalence of misdiagnosis [2]. Research has also shown that up to one third of individuals with adenomyosis can be asymptomatic.  

There are some risk factors associated with the likelihood of having adenomyosis. Most commonly this includes: 

  • Women or AFAB who experience heavy menstrual bleeding or dysmenorrhoea  
  • Prior caesarean delivery 
  • Prior uterine surgery 
  • Women or AFAB over 40 years of age 
  • Genetics or prior family history. 

What are the symptoms of adenomyosis?

  • Heavy bleeding
  • Painful menstruation
  • Chronic pelvic pain
  • Pain before, during, or after sex (dyspareunia)

What causes adenomyosis?

The exact cause of adenomyosis is unknown.

  • The most accepted theory is that the layers between the endometrium and uterine muscle are not separated, which leads to cells growing in places they shouldn’t.
  • A second theory is that uterine muscle cells transform into endometrial-like cells but stay in the muscle area, which leads to a mixture of cells growing in incorrect places.
  • Some researchers also suspect that prior trauma, caused by caesarean section (C-section), uterine surgery, or childbirth may trigger inflammation leading to adenomyosis.  

How is adenomyosis diagnosed?

During your initial appointment, after your GP understands your symptoms, they will perform an abdominal or pelvic exam, or both. Adenomyosis requires further tests to confirm it since many of the symptoms suggestive of adenomyosis will be shared with endometriosis.  

 Your GP will refer you to a gynaecologist or specialist to perform imaging tests (ultrasound or MRI).

  • Transvaginal ultrasound is the first-line imaging choice for symptoms suggestive of adenomyosis because it is more affordable and readily available than an MRI. These ultrasound (or MRI) images should be reviewed by an experienced radiologist to identify the presence of an enlarged uterus and/or an irregularly thick muscle layer. However, one study showed that 48% of patients had normal ultrasounds but still showed symptoms of adenomyosis [3]. This can occur if the individual has diffuse adenomyosis instead of focal adenomyosis. Diffuse adenomyosis is when the tissue similar to the endometrium is spread over a wide area across the muscle layer, and focal is when there are aggregates or groups of cells that grow in the muscle layer [4].  

The only way to fully confirm adenomyosis is to examine the uterus after a hysterectomy has been performed.  

What are the treatments for adenomyosis?

Adenomyosis can significantly impacts sufferers’ quality of life due to the abnormal uterine bleeding and pain symptoms. Doctors should work with patients to create a lifelong management plan based on factors such as age, reproductive status, and symptoms. A key consideration for selecting a treatment method is knowing whether you want to have children – currently or in the future.  

  • Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can be used to relieve pain symptoms.
  • Hormonal therapies such as oral contraceptive pills, progestin pills, GnRH drugs, or intrauterine devices are commonly used to treat adenomyosis. They preserve the uterus and treat the pain symptoms. Some of these treatments will have unwanted side effects. For instance, long-term use of GnRH blocker drugs can cause bone loss, so add-back hormone therapy is commonly used to minimise these side effects. GnRH blocker drugs will also prevent you getting pregnant whilst you are taking them, and the symptoms will return if you choose to stop the therapy.  
  • Hysterectomy is the definitive and permanent treatment for women with adenomyosis, particularly those who are past childbearing age, do not wish to get pregnant, or if they are non-responsive to other treatments. In a partial (or subtotal) hysterectomy, the uterus is removed, leaving the cervix. Patients may prefer partial hysterectomy (leaving the cervix in place) because some women report that the cervix contributes to their sexual enjoyment.  In contrast, a total (or full) hysterectomy removes the uterus and cervix – this procedure is more commonly performed. An experienced gynaecologist will help you determine which procedure is necessary.  

Your gynaecologist or specialist can help you make a decision based on your condition, symptoms, and personal preferences.  

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Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Joii Care website.

References

[1] Leyendecker G, Bilgicyildirim A, Inacker M, Stalf T, Huppert P, Mall G, Böttcher B, Wildt L. Adenomyosis and endometriosis. Re-visiting their association and further insights into the mechanisms of auto-traumatisation. An MRI study. Arch Gynecol Obstet. 2015 Apr;291(4):917-32. doi: 10.1007/s00404-014-3437-8. Epub 2014 Sep 21. PMID: 25241270; PMCID: PMC4355446.

[2] Upson K, Missmer SA. Epidemiology of Adenomyosis. Semin Reprod Med. 2020 May;38(2-03):89-107. doi: 10.1055/s-0040-1718920. Epub 2020 Oct 26. PMID: 33105509; PMCID: PMC7927213.

[3] Orlov, Sofie, and Ligita Jokubkiene. “Prevalence of endometriosis and adenomyosis at transvaginal ultrasound examination in symptomatic women.” Acta obstetricia et gynecologica Scandinavica vol. 101,5 (2022): 524-531. doi:10.1111/aogs.14337

[4] Van den Bosch, T et al. “Sonographic classification and reporting system for diagnosing adenomyosis.” Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology vol. 53,5 (2019): 576-582. doi:10.1002/uog.19096

Written by Joii Team