Endometrial Hyperplasia: Thickened Womb Lining

These two phrases are often mixed up, but they are not the same thing.

• “Thickened endometrium” on an ultrasound is a measurement. It tells you the lining looks thicker than expected. It does not tell you why. A thick lining can be normal at certain times of the month, or can be caused by a polyp, hyperplasia or, less often, cancer.
• “Endometrial hyperplasia” on a biopsy report is a diagnosis. A pathologist has looked at a sample of the lining under a microscope and seen that the glands of the lining have overgrown.

So there is no “normal range” for endometrial hyperplasia, and a scan alone cannot confirm or rule it out. What a scan can do is help decide whether a biopsy is needed. Before menopause, the thickness changes through the monthly cycle, so the number must be read with the day of your cycle. After menopause, if you have had any bleeding, a lining of 4 mm or less is reassuring, and a biopsy is usually advised if it is thicker, looks unusual or the bleeding comes back.

Our uterus cancer page has a simple table that explains what “thickened endometrium” on a scan report means, including the numbers usually used after menopause with and without bleeding. A thickened endometrium alone is not cancer.

The most important word on a biopsy report is atypia. It means some of the cells look abnormal under the microscope. Doctors now group hyperplasia into two types:

• Hyperplasia without atypia. The lining is overgrown, but the cells look normal. The risk of this turning into cancer is low, and many cases go back to normal once the hormone imbalance is corrected or treated.
• Atypical hyperplasia, also called endometrial intraepithelial neoplasia (EIN). The overgrown lining contains abnormal-looking cells. This is a pre-cancer. If it is left untreated, the chance of it turning into womb (endometrial) cancer is much higher, and in some women a small cancer is already present alongside it when the womb is removed and examined.

Older reports may use words such as simple, complex or cystic hyperplasia. “Simple” and “complex” describe how crowded the glands look. “Cystic” usually describes a simple pattern where the glands are widened. What matters most for your plan is still whether atypia is present or not.

The womb lining grows under the effect of oestrogen. Progesterone, which the body makes after ovulation, stops that growth and lets the lining shed as a period. Hyperplasia usually develops when the lining is exposed to oestrogen for a long time without enough progesterone (doctors call this unopposed oestrogen). Common reasons include:

• PCOS (polycystic ovary syndrome), where ovulation is irregular, so the lining is not shed regularly. Our PCOS page explains how the lining can be protected.
• Extra body weight, because body fat makes oestrogen, especially after menopause.
• The years around menopause (perimenopause), when cycles without ovulation are common.
• Oestrogen-only hormone replacement therapy (HRT) in a woman who still has her womb. Adding a progestogen protects the lining, which is why women with a womb are usually given combined HRT.
• Tamoxifen, a medicine used for breast cancer, which can act like oestrogen on the womb lining.
• Diabetes, and, rarely, a hormone-producing ovarian tumour.

Women who develop hyperplasia or womb cancer at a young age, or who have a strong family history of womb, bowel or ovarian cancer, may be offered a test for Lynch syndrome, an inherited condition that raises the risk of these cancers.

The main symptom is abnormal bleeding from the vagina. This can include:

• periods that are heavier or longer than usual;
• periods that become irregular or come too close together;
• bleeding or spotting between periods;
• any bleeding after menopause, even a single episode.

Hyperplasia itself does not usually cause pain, weight gain or bloating. Some women have no symptoms at all, and the thick lining is found on a scan done for another reason.

Bleeding after menopause should always be checked, even if it happens only once. Most women who bleed after menopause do not have cancer, but the check is quick and important. Read more about bleeding after menopause.

The tests usually go in this order, and many women need only the first one or two:

• Transvaginal ultrasound. A thin probe placed in the vagina measures the lining and looks for polyps or fibroids. It can show a thick lining, but it cannot tell whether hyperplasia is present.
• Endometrial biopsy (Pipelle). A thin, soft tube is passed through the cervix to take a small sample of the lining. It is done in the clinic, takes a few minutes, and results usually come in about 1–2 weeks. It may cause cramping for a short time.
• Hysteroscopy. A thin camera is passed into the womb so the doctor can see the lining and take samples from any area that looks abnormal. It is used if a Pipelle biopsy is not possible, does not give enough tissue, or a polyp needs removing.
• D&C (dilatation and curettage). Lining is removed under anaesthesia and sent for testing. It helps with diagnosis, but the lining grows back, so a D&C on its own does not treat hyperplasia.

If atypical hyperplasia is found and you are considering keeping your womb, an MRI scan and a hysteroscopy are often advised first, to look carefully for any hidden cancer before hormone treatment is chosen.

For most women, hyperplasia without atypia is treated without an operation. The plan depends on your age, your symptoms, whether you want a future pregnancy and what is causing the hormone imbalance.

• Treating the cause. Stopping oestrogen-only HRT, reviewing other medicines, and losing weight where needed can help the lining settle and lower the chance of it coming back.
• Hormone-releasing coil (LNG-IUS, for example Mirena). This small device is placed inside the womb and releases a progestogen directly onto the lining. For many women it is the first choice. If it suits you, it is often left in place for up to 5 years.
• Progestogen tablets. These are an alternative for women who do not want or cannot use a coil. Some women notice bloating, mood changes or irregular spotting while taking them.
• Watching alone. In some women the lining goes back to normal by itself once the cause is removed, so careful follow-up without treatment is sometimes discussed. Hormone treatment usually works better.

Treatment usually continues for at least 6 months. A repeat biopsy is commonly done about every 6 months until two in a row are clear. A hysterectomy is not usually the first treatment for this type, but it may be considered if the hyperplasia does not go away, comes back, turns atypical, the bleeding continues, or you prefer not to have repeated follow-up.

Because atypical hyperplasia is a pre-cancer, and because a small cancer is sometimes already present, the usual advice for women who do not want a future pregnancy is a total hysterectomy: removal of the womb and cervix, usually together with the fallopian tubes. Whether the ovaries are also removed depends mainly on your age and whether you have reached menopause, and is discussed with you beforehand.

In many women this operation can be done by keyhole (laparoscopic) or robotic surgery, which usually means smaller cuts and a quicker recovery. It is not right for everyone; the choice depends on the size of the womb, your general health and any previous surgery. Robotic surgery is available at Sterling Hospitals and KD Hospital in Ahmedabad.

If you still hope to become pregnant, a fertility-sparing route may be possible in selected women. After an MRI and hysteroscopy to look for hidden cancer, the lining is treated with a hormone-releasing coil or high-dose progestogen tablets, and a repeat biopsy is done about every 3 months to check that the atypia has gone. This needs close follow-up and is not suitable for everyone. Once your family is complete, a hysterectomy is usually recommended because the condition can come back. Our page on fertility-sparing hormone treatment for early womb cancer explains how this kind of plan works, since atypical hyperplasia is treated in a similar way.

Endometrial hyperplasia is not cancer. Hyperplasia without atypia is usually looked after by a gynaecologist. A women’s cancer specialist (gynaecological oncologist) should usually be involved if:

• your biopsy shows atypical hyperplasia or EIN, or the report mentions possible cancer;
• you want to keep your fertility despite atypical hyperplasia;
• hyperplasia keeps coming back or does not respond to treatment;
• you have a strong family history of womb, bowel or ovarian cancer.

If a hysterectomy shows that a small cancer was present, it is usually at a very early stage. Our endometrial cancer page explains what happens next. If you have been advised surgery and would like an independent review of your report and plan, you can ask for a second opinion.

If your scan or biopsy report mentions a thickened lining or endometrial hyperplasia and you are not sure what it means for you, Dr. Nishtha Tripathi Patel, an ESGO-certified gynaecological oncologist, can review your reports and explain your options in plain words. She sees patients at Sterling Hospitals, KD Hospital and Welcare Speciality Hospital in Ahmedabad, and video consultations are also available. Please book an appointment and bring your scan and biopsy reports with you.