Endometrial hyperplasia explained

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

Osama Naji

Endometrial hyperplasia is a medical condition characterised by the abnormal thickening of the lining of the uterus, called the endometrium. It occurs when the cells that make up the endometrium grow and multiply in an uncontrolled way, causing the lining to become thicker than usual.

Here, Consultant Gynaecologist Osama Naji takes us through the causes, symptoms, diagnosis and  treatment for endometrial hyperplasia

What causes endometrial hyperplasia?

Endometrial hyperplasia is often caused by an imbalance of hormones, such as an excess of estrogen, which if left to continue for long time, may lead to endometrial hyperplasia.

Certain conditions make endometrial hyperplasia more likely due to increased oestrogen. These include:

• increased body weight, particularly a body mass index (BMI) over 30
• taking estrogen only HRT
• if you have never been pregnant
• untreated polycystic ovary syndrome (PCOS)
• you have a type of tumour of the ovary that secretes estrogen, such as a granulosa cell tumour
• you take a medicine called tamoxifen (a hormone therapy used to treat breast cancer).
• diabetes
• a family history of ovarian, bowel or womb cancer.

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 low risk of developing into cancer. In this type, more normal cells are being produced and accumulate, making the lining of the womb thicker.

Complex endometrial hyperplasia with atypia (also known as typical hyperplasia) has a higher 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 type of hyperplasia is more likely to become cancerous over time, if not treated.

What are the symptoms?

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 on HRT.
• vaginal bleeding after the 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 the womb and look for other causes of abnormal uterine bleeding at the same time, such as polyps, fibroids or presence of any cysts on the ovaries. 

An endometrial biopsy

An endometrial biopsy is when we take a sample of tissue from the lining of the 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 the cervix (the neck of the 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 the 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 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 Mirena coil or progesterone tablets, to help the cells go back to normal. Another option is to do nothing and repeat the biopsy after 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 in such scenarios. 

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 the womb). This is usually done as a robotic or laparoscopic surgery (keyhole surgery). If you want to get 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 the woman’s age and reproductive goals.

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 to monitor for progression or recurrence, as they have a higher risk of developing endometrial cancer and require more aggressive management.

After treatment for endometrial hyperplasia, regular follow-up visits with a gynaecologist are important to monitor for recurrence or progression of the condition. This may include periodic endometrial biopsies, imaging studies, and blood tests.

Women who have undergone hysterectomy for atypical hyperplasia should also receive regular pelvic exams and may require further testing if any signs of genital tract bleeding develop. Women who take HRT can 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
• bleeding persists despite a normal biopsy.

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 estrogen as part of HRT
• taking the oral contraceptive pill or progesterone to regulate your menstrual cycle if you have PCOS
• seeking an early advice for abnormal bleeding if you are taking medications such as Tamoxifen.

About the author

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.

He offers a “one-stop” gynaecology clinic for instant detection of various gynaecological cancers as well as providing all the diagnostic and treatment services needed under one roof.

You can read more about Mr Naji here.