Within the uterus, there are two distinct layers: The endometrium is the inner layer, which is sensitive to hormone receptors. It will grow thicker in the first half of the menstrual cycle and finally gets expelled as periods in regular intervals (28 days). The myometrium is a thick layer of smooth muscle tissue surrounding the endometrium and normally does not change throughout the menstrual cycle.
Adenomyosis is a condition in which cells of the endometrium are dispersed throughout the myometrium. As a consequence, the uterus will swell up during the build up of the endometrium and then the body will try to expel the endometrium tissue from the myometrium, which is impossible, thus causing pain.
(Endometriosis is a condition in which endometrial tissue is dispersed throughout the pelvis).
Incidence
Has not been established accurately. Up to 20% of women could be affected by mild, moderate or severe adenomyosis.
Risk factors: Unclear. Adenomyosis is commonly diagnosed with other gynaecological conditions, such as fibroids (in about 50%) and endometriosis.
Symptoms
The main symptoms include heavy menstrual bleeding (menorrhagia, clots) and painful periods (dysmenorrhoea). Symptoms typically develop between 30 and 40 years of age. One third of women diagnosed with adenomyosis (incidentally at hysterectomy) have had no symptoms.
Diagnosis
A definitive diagnosis can only be made from the tissue (histopathology) examination of a hysterectomy specimen. The diagnosis is suspected when typical symptoms occur.
Ultrasound may provide information and in particular Doppler ultrasound may reveal some blood flow within the smooth muscle layer that is normally absent. Also, doctors are suspicious of adenomyosis if patients present with the above symptoms but don’t have fibroids or any other pathology on ultrasound.
A preoperative diagnosis of adenomyosis is difficult to establish but can be attempted through MRI scan. It can show strong signal intensity within the myometrium on T2 weighted scans. MRI scanning is also the best to distinguish adenomyosis from fibroids. Unfortunately, MRI scanning is expensive in Australia and unavailable in a number of countries for cost reasons.
Computed tomography (CT scan) is unreliable to diagnose or exclude adenomyosis.
Treatment options:
- Medical treatment – There are no large or well controlled studies on the treatment of adenomyosis. This means that treatment relies heavily on the opinion of experts and their experience. It is also accepted that medical treatment (Mirena, systemic Progestins, oral contraceptives, Danazole) can provide initial symptom relief for some patients, but symptoms will recur once treatment has stopped.
2. Surgery
- Local excision is not a surgical option because there is no clear surgical plane between adenomyosis and the surrounding uterus.
- Endometrial ablation is a good option for treatment of bleeding irregularities that are caused by diseased endometrium but not a great choice for the treatment of processes within the myometrium.
- Hysterectomy is the definitive procedure with no chance of recurrence of bleeding or pain beyond the postoperative recovery. Hysterectomy should be done vaginally or laparoscopically (key hole or minimally invasive surgery); if the opening of the abdomen is recommended, I recommend that patients look for a second opinion. Information on hysterectomy can be found here.
3. Interventional radiology
- Uterine artery embolisation is an option for women who wish to preserve the uterus but are not interested in pursuing fertility. It is a minimally invasive procedure but associated with a much higher risk of treatment complications and readmissions to hospital than hysterectomy. In addition, half of women treated with uterine artery embolisation require additional treatments and one in three end up having a hysterectomy because of persistent symptoms.
- Magnetic resonance guided focused ultrasound is an emerging and novel procedure with very limited data to date. It was introduced to Australia in 2009.