Adenomyosis is uterine enlargement due to focal or diffuse ectopic rests of endometrial tissue within the myometrium. It is most likely due to direct invasion of the endometrium into the myometrium. It is characterised by abnormal uterine bleeding and secondary dysmenorrhea.
It peaks between 40 and 50 years.

- Risk factors
- Age: 80% of cases in 40s-50s
- Multiparity
- 90% of cases in parous women
- Prior uterine surgery
- Smoking
- Antidepressants
- These alter the balance of prolactin
- Tamoxifen
- Estrogen agonist in the uterus
- Pathophysiology
- Increased vascularization of the endometrium near the adenomyotic foci and ectopic estrogen production → menorrhagia
- Similarities between fibroids and adenomyosis
- Signs and symptoms
- Abnormal uterine bleeding
- Secondary Dysmenorrhea
- Pelvic pain
- Similar to uterine contractions in labour
- May not be localized to the uterus or pelvis
- Dyspareunia (10%)
- Subfertility
- Physical exam
- Enlarged and tender uterus
- Diffusely enlarged and boggy
- Focal adenomyosis can presents a fibroids
- Enlarged and tender uterus
- Investigations
- Transvaginal ultrasound is the best initial test
- Increased thickness of the myometrium
- Myometrial heterogeneity
- Small hypoechoic cysts in the myometrium
- Striated projections from endometrium into myometrium
- MRI to distinguish adenomyosis from fibroids
- Transvaginal ultrasound is the best initial test
- Treatment
- Combined oral contraceptives or Progestins to control bleeding
- NSAIDs to relieve pain
- NSAIDs can also be used in place of contraceptives if pregnancy is desired
- Surgery
- Hysterectomy is the most definitive treatment
- Endometrial ablation
- Uterine artery embolization