Endometrial hyperplasia is the proliferation and thickening of the endometrium. It is usually considered in post-menopausal women with an endometrial stripe measuring > 5 mm thick with post-menopausal bleeding, and > 10 mmthick without.
Normal endometrial thickness variations during the menstrual cycle
| Phase | Endometrial Thickness | Hormonal Influence | Ultrasound Appearance |
|---|---|---|---|
| Menstrual flow (Days 1-5) | 1–4 mm | Low estrogen & progesterone | Thin, echogenic line |
| Proliferative phase (Days 6-14) | 5–7 mm (early) → 8–12 mm (late) | Rising estrogen | Triple-line pattern (hypoechoic basal layer + hyperechoic lines) |
| Secretory phase (Days 15-28) | 7–16 mm | Progesterone dominance | Homogeneous, hyperechoic |
| Postmenopausal | <4–5 mm (without hormone replacement therapy) | Low estrogen | Thin and atrophic |
Terms used to describe the histology of endometrial hyperplasia
| Term | Description |
|---|---|
| Simple hyperplasia | Normal endometrial architecture but increased glands and stroma. The ratio may be slighly increased, i.e, > 1:1 |
| Complex hyperplasia | Changes in endometrial architecture (crowding and invaginations), and/or increased gland to stroma ratio (> 3:1) |
| Atypical hyperplasia (atypia) | Changes in the nuclear structure of the cells (prominent nucleoli, salt-pepper chromatin, and mitotic figure) |
Risk of progression to cancer
| Histology | Risk |
|---|---|
| Simple without atypia | 1% |
| Complex without atypia | 3% |
| Simple with atypia | 8% |
| Complex with atypia | 29% |
- Risk factors
- Hyperestrogenism (unopposed estrogen)
- High-dose menopausal estrogens
- Obesity (more aromatase more estrogen)
- Nulliparity
- Early menarche (≤ 11 years)
- Late menopause
- Use of Tamoxifen
- Polycystic ovarian syndrome (anovulation → unopposed estrogen)
- Type 2 diabetes
- Hypertension
- Gallbladder Disease
- Obesity
- White race
- High socio-economic sttus
- Older age
- Living in North America or Northern Europe
- Hyperestrogenism (unopposed estrogen)
- Signs and Symptoms
- Abnormal uterine bleeding
- Post-menopausal bleeding
- Menorrhagia
- Intermenstrual spotting
- Abnormal uterine bleeding
- Physical Exam
- Pelvic exam (bimanual and speculum): feel for masses (fibroid, polyps, ovarian tumours), exclude lacerations, foreign bodies, cervical cancer
- Investigations
- Transvaginal ultrasound to measure the endometrial stripe
- The normal endometrium varies from 4 – 16 mm in pre-menopausal women
- Endometrial stripe < 5mm is likely endometrial atrophy in post-menopausal women
- Endometrial stripe ≥ 5 mm is likely endometrial hyperplasia in post-menopausal women
- Endometrial biopsy if:
- Age > 40 years
- There are risk factors for endometrial carcinoma
- There is significant intermenstrual bleeding
- There is failure of medical treatment for abnormal bleeding
- Transvaginal ultrasound to measure the endometrial stripe
- Treatment
- Progestins for hyperplasia without atypia
- Medroxyprogesterone acetate
- Megestrol
- For hyperplasia with atypia:
- Hysterectomy
- High dose medroxyprogesterone acetate if fertility needs to be preserved
- Progestins for hyperplasia without atypia