Endometrial Hyperplasia

Endometrial hyperplasia is excessive thickening of the endometrium, the lining of the womb. It is not cancer, but diagnosis and follow-up matter because some types can predispose to cancer over time. It is often noticed through abnormal uterine bleeding, and diagnosis requires microscopic examination. The information below offers a general overview and does not replace an individual diagnosis or treatment advice.

What is endometrial hyperplasia?

During the menstrual cycle, oestrogen causes the endometrium to thicken, progesterone causes it to mature, and it is shed with menstrual bleeding. When oestrogen's effect is not balanced by progesterone, the tissue grows irregularly and thickens. This is called hyperplasia. Classification depends on the cellular features of the thickened tissue. Ultrasound thickness alone cannot make this distinction.

What types of hyperplasia are there?

Current medical guidance divides hyperplasia into forms without atypia and atypical forms; some sources also use the term endometrial intraepithelial neoplasia (EIN) for the same problem. The systems overlap substantially but are not identical.

How do hyperplasia with and without atypia differ?

Atypia means structural changes in cells that may be precancerous. Hyperplasia without atypia has a lower cancer risk, with management mainly involving hormonal treatment and monitoring. In atypical hyperplasia, the risk is markedly higher, and both exclusion of coexisting cancer and treatment are pursued more actively. The word hyperplasia on a biopsy report does not make these two conditions the same.

What causes endometrial hyperplasia, and what are its risk factors?

The common factor is an oestrogen effect unbalanced by progesterone. Situations that may increase this effect include:

• Irregular ovulation, for example in polycystic ovary syndrome
• Excess weight
• Use of certain hormonal medicines

Risk factors do not mean hyperplasia will necessarily develop. It can also occur without them.

What symptoms can endometrial hyperplasia cause?

The most common symptom is abnormal uterine bleeding: bleeding outside periods, prolonged or heavy periods, or bleeding after menopause. Periods may become irregular before menopause. Some people have no symptoms, and hyperplasia is noticed during investigations for another reason. A new irregular bleeding pattern should be assessed.

How is endometrial hyperplasia diagnosed?

Is ultrasound sufficient for diagnosis?

No. Transvaginal ultrasound may show a thickened lining, which raises suspicion but does not establish hyperplasia. Polyps, fibroids or normal cyclical changes can look similar.

Which sampling methods are used for diagnosis?

Diagnosis requires histological examination of endometrial tissue. Outpatient endometrial biopsy is often the first step. Hysteroscopy is recommended if the biopsy is insufficient or not diagnostic. Current medical guidance holds that hysteroscopy-guided biopsy is more sensitive than blind curettage for diagnosing uterine lesions.

Does a Pap smear screen for hyperplasia?

No. A Pap smear screens cervical cell changes, not the uterine lining reliably. A normal smear or HPV result does not remove the need for endometrial assessment, particularly with postmenopausal bleeding.

How is coexisting cancer excluded after a hyperplasia diagnosis?

The priority after a hyperplasia diagnosis is to establish whether endometrial cancer is also present. Current medical guidance holds that hysteroscopy with additional sampling is among the most reliable methods for detecting coexisting cancer. Assessment is more comprehensive in atypical hyperplasia because coexisting cancer is more likely. If cancer is found, treatment follows a separate pathway with a gynaecological oncology team.

How is endometrial hyperplasia treated?

How is hyperplasia without atypia treated?

For hyperplasia without atypia, current medical guidance recommends a levonorgestrel-releasing intrauterine system as the first option. Oral progestins may be used by those who do not prefer this method. The doctor determines treatment duration and dose individually. Biopsies are performed during treatment to demonstrate regression at tissue level. Side effects should be shared with the doctor.

How is atypical hyperplasia treated?

Current medical guidance holds that hysterectomy, or removal of the womb, is the main treatment for atypical hyperplasia. Progestin treatment with close monitoring may be used in selected people wishing to preserve fertility or unsuitable for surgery. This is an individual decision. The doctor explains the benefits, risks and limitations of surgery and hormonal treatment together.

Can it recur after treatment?

Yes. Hyperplasia may return after hormonal treatment, so regular review matters. Hysterectomy may be considered if tissue does not regress with treatment, atypia develops or pregnancy is no longer wanted and recurrence risk remains high. Report new bleeding during hormone treatment.

Can hyperplasia affect pregnancy plans?

For someone wishing to become pregnant, demonstrating regression at tissue level before trying is recommended. Referral to a reproductive medicine specialist may be made for this purpose. As irregular ovulation can be a cause of hyperplasia, pregnancy plans are considered alongside treatment planning.