Endometrial hyperplasia explained

Learn about the causes, symptoms and treatment options of endometrial hyperplasia

Endometrial hyperplasia can be caused by an imbalance of hormones
Symptoms can include heavy or irregular periods or bleeding after menopause
Treatment options and prevention tips

Endometrial hyperplasia simply means thickening of the lining of the uterus (womb), called the endometrium. It occurs when the cells that make up the endometrium grow and multiply, causing the lining to become thicker than usual.

What causes endometrial hyperplasia?

Endometrial hyperplasia is often caused by an imbalance of hormones. It can cause vaginal bleeding. It often returns to normal without any treatment. When women are having periods, hyperplasia can be common as the lining of the womb naturally builds up before it is shred (leading to a period).

Certain conditions make endometrial hyperplasia more likely. These include:

increased body weight, particularly a body mass index (BMI) over 30
taking oestrogen-only HRT
untreated polycystic ovary syndrome (PCOS)
you have a type of tumour of the ovary that secretes oestrogen, such as a granulosa cell tumour
you take a medicine called tamoxifen (a hormone therapy used to treat breast cancer)
being perimenopausal

What are the types of endometrial hyperplasia?

There are several types of endometrial hyperplasia, these vary in their degree of abnormal cell growth and the risk of developing into endometrial cancer.

The most common type is called simple hyperplasia without atypia, which has a very low risk of developing into cancer. In this type, more normal cells are being produced and accumulate, making the lining of the womb thicker. In most people with simple endometrial hyperplasia, the hyperplasia improves spontaneously without treatment.

Complex endometrial hyperplasia with atypia (also known as atypical hyperplasia) has a small risk of progressing to endometrial cancer, and it is important to identify and treat this condition promptly. In this type, abnormal (atypical) cells are being produced. This is not cancer.

What are the symptoms of endometrial hyperplasia?

Symptoms of endometrial hyperplasia usually occur in the form of abnormal uterine bleeding. This condition may also be incidentally discovered during pelvic imaging.

Common symptoms include:

heavy/ irregular periods
bleeding in between periods
unscheduled or irregular bleeding while you are taking HRT
vaginal bleeding after menopause
increasing brown/red vaginal discharge

How is endometrial hyperplasia diagnosed?

An ultrasound scan

An ultrasound scan is usually arranged if your doctor thinks you may have endometrial hyperplasia. It is performed to measure the thickness/appearance of the lining of your womb and look for other causes of abnormal uterine bleeding at the same time, such as polyps, fibroids or presence of any cysts on your ovaries.

RELATED: Fibroids and menopause

An endometrial biopsy

An endometrial biopsy is when a sample of tissue is taken from the lining of your womb. It is often an outpatient procedure and usually does not require an anaesthetic. A thin lighted tube and a camera (hysteroscope) is inserted through your cervix (the neck of your womb) to visualise the lining and obtain some cells. Alternatively, a sample can be taken though a small plastic tube without a camera (pipelle endometrial sampling).

A hysteroscopy

A hysteroscopy allows your doctor to see inside your womb using a thin tube-like camera. It can identify any abnormalities inside your womb and take a biopsy from it. This procedure can be carried out in the outpatient clinic with or without a local anaesthetic. It can also be done under a short general anaesthetic in the operating theatres, and you will be allowed home on the same day. The tissue is studied under a microscope to confirm if endometrial hyperplasia is present.

How is endometrial hyperplasia treated?

Treatment options for endometrial hyperplasia depends on which type you have.

Endometrial hyperplasia without atypia

Your doctor could recommend some form of hormone treatment, either in the form of the Mirena coil or progesterone tablets, to help the cells go back to normal. Another option is to do nothing and repeat the biopsy after around six months to see if the changes have regressed. The risk of developing cancer of the lining of the womb over 20 years is less than one in 20.

Atypical endometrial hyperplasia

If you have atypical endometrial hyperplasia, there is a higher risk of developing endometrial cancer if this condition is not treated. Your specialist may recommend you have a hysterectomy (an operation to remove your womb). This is usually done as a robotic or laparoscopic surgery (keyhole surgery). If you want to become pregnant, you can discuss the fertility preserving options with your specialist.

Follow-up of endometrial hyperplasia

The follow-up of endometrial hyperplasia depends on the type and severity of the condition, as well as your age and whether you want to have a baby. Here are some general recommendations:

Follow-up appointments are required to see if cells are going back to normal if you have endometrial hyperplasia without atypia. This could be a repeat endometrial biopsy and a hysteroscopy after six and 12 months from the start of treatment. Most patients are discharged after two negative biopsies.

Women with atypical hyperplasia may require closer follow-up than those with simple hyperplasia, including more frequent endometrial biopsies unless they have had a hysterectomy.

After treatment for endometrial hyperplasia, regular follow-up visits with a gynaecologist are important to monitor for recurrence or progression of the condition. The follow up and future trests will depend on the treatment you have received.

Women who take HRT can usually be advised they can continue but to include either continuous progesterone, or the Mirena coil – since it produces localised high progesterone dose that is only absorbed by the lining of the uterus with very minimal systemic side effects.

A hysterectomy (removal of the womb) may be considered if:

the endometrial hyperplasia persists
the condition returns after treatment
you develop atypical hyperplasia

How can I prevent endometrial hyperplasia?

You can lower the risk of endometrial hyperplasia by:

treating endometrial hyperplasia without atypia with progesterone
maintaining a healthy body weight
taking progesterone in combination with oestrogen as part of HRT
seeking an early advice for abnormal bleeding if you are taking medications such as tamoxifen

Osama Naji is a Consultant Gynaecologist at Guy’s and St Thomas’ NHS Foundation Trust, where he leads the Rapid Access Service for Cancer Diagnostics at Guy’s Cancer Centre. You can read more about Mr Naji here.