Essentials

The risk of adenomyosis is increased by childbirth, miscarriage, uterine curettage and menorrhagia.
The symptoms resemble those of endometriosis.
An underdiagnosed disease
In fertile age treated like endometriosis
Hysterectomy is the best and final treatment for older women with severe symptoms.

General remarks

Adenomyosis is characterised by the presence of intramyometrial foci of endometrial glandular and stromal cells (in endometriosis, endometriotic tissue is found outside the uterus).
The foci of adenomyosis react to oestrogen in a manner similar to that of endometrium.
The foci have either diffuse (usually in the posterior uterine wall) or local (adenomyoma) distribution where a large number of foci become localised in one area.
The aetiology remains unclear.
The risk of adenomyosis is increased by childbirth, miscarriage, uterine curettage and menorrhagia.
Currently adenomyosis is suspected to be associated also with infertility and hence to be more common than previously thought; in 5–70% of women.
Most common at the age of 35–50 years
Changes are found in 15–20% of hysterectomy patients.
About 40% of patients with endometriosis also have adenomyosis.

Symptoms

An enlarged and tender uterus
Feeling of heaviness in the lower abdomen
Chronic lower abdominal pain
Infertility; impaired attachment of the embryo to the uterine wall
40–50% have menorrhagia
10–30% have dysmenorrhoea
30–40% are symptom free
The symptoms are similar to those of endometriosis (Endometriosis) and differential diagnosis may prove to be difficult.

Diagnosis

Gynaecological examination will reveal uterine tenderness.
The ultrasound appearance is that of thickened posterior uterine wall and hypoechoic and blind areas of 1–5 mm in the myometrium.
An MRI scan will show thickening of the junctional zone (the interface between the endometrium and myometrium) or a lesion with poorly defined borders (adenomyoma).
Diagnosis is challenging and can only be confirmed with a histopathological examination carried out after hysterectomy.
Diagnosis may also be obtained by a biopsy taken through hysteroscopy or laparoscopy.

Treatment

Prostaglandin inhibitors (anti-inflammatory drugs) reduce menorrhagia and pain in one third of patients.
Tranexamic acid halves menorrhagia.
Combined oral contraceptive pills as well as progestin pills are effective in reducing both menorrhagia and pain.
Levonorgestrel-releasing intrauterine device (IUD) reduces menorrhagia and pain in up to 90% of patients.
A gonadotropin-releasing hormone agonist (GnRH agonist) will cause a hypo-oestrogenic state and amenorrhoea leading to both cessation of menorrhagia and pain as well as reduction in the size of the foci (adverse effects include menopausal symptoms if oestrogen/progestogen is not used as add-back therapy).
Uterine artery embolization reduces menorrhagia related to adenomyosis and the number of bleeding days.
Surgical excision of a localised adenomyoma is possible.
The new MRI- or ultrasound-guided focused ultrasound (HIFU, high-intensity focused ultrasound) seems to alleviate the symptoms of adenomyosis.
The aforementioned treatments alleviate symptoms but there is no scientific evidence on them in improving fertility.
Hysterectomy is the best and final treatment for older women with severe symptoms in whom the above treatment forms have proved ineffective.

References

1. Maheshwari A, Gurunath S, Fatima F et al. Adenomyosis and subfertility: a systematic review of prevalence, diagnosis, treatment and fertility outcomes. Hum Reprod Update 2012;18(4):374–92. [PMID:22442261]

2. Zhai J, Vannuccini S, Petraglia F et al. Adenomyosis: Mechanisms and Pathogenesis. Semin Reprod Med 2020;38(2-03):129–143. [PMID:33032339]

3. Struble J, Reid S, Bedaiwy MA. Adenomyosis: A Clinical Review of a Challenging Gynecologic Condition. J Minim Invasive Gynecol 2016;23(2):164–85. [PMID:26427702]

4. Pontis A, D'Alterio MN, Pirarba S et al. Adenomyosis: a systematic review of medical treatment. Gynecol Endocrinol 2016;32(9):696–700. [PMID:27379972]

5. Dueholm M. Minimally invasive treatment of adenomyosis. Best Pract Res Clin Obstet Gynaecol 2018;51:119–137. [PMID:29555380]