Adenomyosis

Adenomyosis is a gynaecological condition characterised by the abnormal growth of endometrial tissues (uterine lining) in the myometrium (uterine wall). Adenomyosis is relatively common, affecting between 20% to 35% of women [1].

What is Adenomyosis?

Adenomyosis is a condition characterised by the ectopic growth of endometrial tissues within the myometrium of the uterus. This causes a variety of symptoms such as heavy menstrual bleeding and painful menses. Adenomyosis lesions can take several forms [2]:

• Focal adenomyosis – Focal adenomyosis is known for isolated lesions within the myometrium.
  
• Diffuse adenomyosis – In diffuse adenomyosis, the lesions or foci are spread out within the myometrium.
  
• Adenomyoma – Adenomyoma is a more extensive form of focal adenomyosis, characterised by a nodular growth surrounded by a well-defined border of normal myometrium tissues. 

Adenomyosis vs Endometriosis

Both adenomyosis and endometriosis are relatively common gynaecological conditions. Both conditions are characterised by abnormal growth of endometrial tissues. Both of these conditions share many similarities, but they are two separate conditions. Some women can have both adenomyosis and endometriosis at the same time. The main difference of these conditions is the location of the tissue growth.

Adenomyosis	Endometriosis
Endometrial tissue growth within the myometrium or uterine wall.	Endometrial tissue growth outside of the uterine cavity, such as on the ovaries, fallopian tube, or on the outer wall of the uterus.

What are the symptoms of Adenomyosis?

Adenomyosis shares similar symptoms with many other uterine conditions, these include:

• Heavy menstrual bleeding
• Painful menstruation
• Tender or enlarged uterus
• Pain during sexual intercourse
• Pelvic pain
• Bloating or sense of pelvic fullness 

Some cases of adenomyosis may even be asymptomatic, or showing no symptoms. This is why adenomyosis can be difficult to diagnose.

Complications of Adenomyosis

Several complications associated with adenomyosis include:

• Infertility – Adenomyosis is associated with an increased risk of infertility, this is likely due to an altered uterine environment, abnormal contractions, increased inflammation, and abnormal endometrium [3].
  
• Anaemia – Anaemia can be attributed to heavy menstrual bleeding due to adenomyosis. It is important that you seek medical advice to treat anaemia if you experience heavy bleeding.
  
• Fatigue – The symptoms and complications of adenomyosis, such as anaemia and severe pain, can lead to fatigue, dizziness, and a poor quality of life.

What causes Adenomyosis?

Adenomyosis is caused by an infiltration and growth of endometrial cells in the myometrium. The exact mechanisms of how the endometrial cells are deposited within the myometrium are not fully understood, some of the proposed mechanisms include uterine injuries from surgery, childbirth, or Caesarean delivery [3].

Increased oestrogen levels contribute to the proliferation of the endometrial tissues, which leads to the formation and growth of the adenomyosis foci or lesions [1]. Consequently, the excess growth of endometrial tissue leads to the common symptoms of adenomyosis. Dysmenorrhoea, or painful menstrual cramps, is believed to be caused by prostaglandin production by these endometrial tissues. While increased menstrual bleeding is thought to be attributed to the increase in endometrial tissue, vascularisation, abnormal uterine contractions, and increased levels of prostaglandin and oestrogen [1].

What are the risk factors of Adenomyosis?

Anyone can be at risk of adenomyosis. However, considering the cause and pathogenesis of adenomyosis, the risk increases with the following factors:

• Age – Adenomyosis is commonly seen in middle-aged premenopausal women.
  
• Oestrogen levels – Similar to other uterine conditions, adenomyosis risk increases with increased oestrogen exposure. This can come in the form of increased parity, shorter menstrual cycle, high BMI, and use of medications such as oral contraceptive or tamoxifen [1].
  
• Pregnancy – Previous pregnancies can introduce minor injuries that cause the invagination of endometrial cells into the myometrium. Hormonal changes in pregnancy can also contribute to an increased risk of developing adenomyosis. Pregnancy increases oestrogen levels, which is implicated in the development of adenomyosis. Additionally, prolactin, a hormone responsible for lactation, is also thought to lead to the weakening of the myometrium, increasing the risk of endometrial cell invasion [4].
  
• History of surgery – Previous uterine surgeries such as dilation and curettage, Caesarean births, or fibroid removal, can introduce microtraumas within the uterine walls.
  
• Endometriosis – Both endometriosis and adenomyosis are associated with each other. Some women can have both conditions at the same time. 

How is Adenomyosis diagnosed?

Adenomyosis can be challenging to diagnose, as the condition shares many similar symptoms with other uterine conditions and some cases may even be asymptomatic. A thorough diagnosis with your gynaecologist can help diagnose your condition and determine a treatment plan.

Adenomyosis can be diagnosed with the following tests [1, 2]:

• Physical examination – During your visit to the clinic, your doctor will ask you to describe your symptoms and take your medical history. Your history of surgeries, pregnancy or childbirth, can help the doctor identify the possible causes of your symptoms. A physical examination will involve a pelvic examination, your doctor may palpate and feel your pelvic organs to look for any signs of tenderness, pain, or enlargement of the uterus.
  
• Ultrasonography – A transvaginal ultrasound allows your doctor to detect the adenomyosis foci. A transvaginal ultrasound involves inserting the ultrasound probe from your vagina to observe the uterus and other pelvic organs to look for signs of adenomyosis foci.
  
• Magnetic resonance imaging (MRI) – Similar to an ultrasound, an MRI scan allows your doctor to observe and locate the adenomyosis foci in the uterus.
  
• Laboratory tests –  Laboratory tests such as tissue biopsies and histological examination can be performed if your doctor suspects other conditions that may appear similar to adenomyosis, such as uterine cancers. The tissue samples for these lab tests can be obtained from hysteroscopic or laparoscopic procedures [4].

How is Adenomyosis treated?

Adenomyosis can be left untreated if they are asymptomatic or only cause mild symptoms. Typically, once you reach menopause, adenomyosis can go away on its own. However, patients who do experience symptoms can receive treatment depending on the severity of the symptoms [5].

Non-surgical treatment

• Pain medication – Pain medications such as non-steroidal anti-inflammatory drugs (NSAIDs) can relieve painful menstrual cramps in adenomyosis patients. NSAIDs can also reduce heavy bleeding associated with adenomyosis. However, common side effects of NSAIDs include gastrointestinal irritation and potential renal toxicity, hence it is recommended to follow your doctor’s instructions when taking these medications.
  
• Hormone therapy – Hormone therapy for the management of adenomyosis include oral contraceptives, levonorgestrel-releasing intrauterine devices (IUDs), progestins, and gonadotropin-releasing hormone agonists/antagonists. These work by reducing the excessive growth of endometrial tissues, hence reducing heavy bleeding.
  
• Tranexamic acid – Certain non-hormone medications such as tranexamic acid, reduces heavy bleeding by slowing down the breakdown of blood clots. This can be an alternative for those who prefer not to take contraceptive pills or hormone therapy. 

Surgical treatment

• Uterine artery embolisation – Uterine artery embolisation is commonly indicated for the treatment of uterine fibroids, but can be used to treat focal adenomyosis as well [5]. The procedure is minimally invasive, and involves blocking the artery that supplies blood into the adenomyosis lesion, leading it to be starved and eventually shrink.
  
• Adenomyomectomy – Adenomyomectomy is a surgical procedure involving the removal of the adenomyosis foci from the myometrium. This procedure is recommended for those with severe symptoms who wish to preserve fertility and be able to get pregnant in the future. However, certain risks are associated with the procedure, including adenomyosis relapse, adhesion, and potential uterine rupture during pregnancy [6].
  
• Hysterectomy – A hysterectomy is the removal of the uterus. This procedure is considered the definitive cure for severe adenomyosis. Patients who no longer wish to get pregnant can be recommended for a hysterectomy. 

Treatment of adenomyosis can vary according to the symptoms and severity of the disease. An in-depth discussion with your doctor can allow you and your doctor to select the most appropriate treatment methods for your condition and future pregnancy plans. 

Summary

Adenomyosis is a condition of the overgrowth of endometrial tissues in the uterus musculature. Although some cases of adenomyosis may be asymptomatic and require no treatment, other patients may experience serious symptoms and complications, such as anaemia and infertility. Treatment of adenomyosis can depend on your symptoms and severity, as well as your plans for future pregnancy. 

Book a consultation with us for a detailed diagnosis and personalised treatment plan.