Endometrial stromal sarcoma | Sarcoma UK
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Endometrial stromal sarcoma

Endometrial stromal sarcoma is a type of sarcoma, which is a type of cancer. It begins in the connective tissue cells.

These cells are found in the inner lining of the uterus, which is called the endometrium.

Endometrial stromal sarcoma, also known as “ESS”, is a rare type of sarcoma. It is also sometimes called uterine sarcoma. ESS can be:

  • Found in the uterus
  • Found in the uterus, but has also spread to nearby parts of the body such as the pelvis
  • Found in the uterus, but has spread to other, more distant parts of the body

ESS is also described as being either high-grade or low-grade. This helps to explain how likely it is to grow and spread.

  • When ESS is low-grade, the cancer cells only look a little different from normal cells. The cancer will likely grow slowly.
  • High-grade ESS means the cancer cells look different from normal cells. The cancer may grow quickly.

ESS only occurs in people who have a uterus. It tends to affects younger females between the ages of 40 and 60.

The cause of ESS is unknown. Some research suggests a connection between ESS and hormone therapies, pelvic radiotherapy, and polycystic ovary syndrome (PCOS).

It’s important to remember that the risk of developing ESS because of hormone therapy or pelvic radiotherapy is low, and doctors will always consider the benefits of treatment compared with the small risks. Researchers are still trying to learn more about the causes of ESS.


There are an average of 79 cases of endometrial stromal sarcoma diagnosed every year in England.

Although it can affect anyone of any age, the median age at diagnosis is 55 years old.

For more information on these statistics, you can visit our soft tissue sarcoma data hub.

Signs and symptoms

Symptoms of ESS can vary depending on the size and location of your tumour.

Before you are diagnosed, you may experience all, some or none of these symptoms:

  • Abnormal bleeding from the vagina, such as:
    • Bleeding between periods
    • More bleeding than usual during a period
    • Bleeding after menopause
  • Abnormal discharge from the vagina
  • Pain in the pelvic or stomach region
  • A lump that you can feel in the pelvic or stomach region
  • Changes in how you pee, such as peeing more often
  • Constipation

If you have any of these symptoms, you should visit your GP.


A specialist sarcoma doctor or gynaecologist will diagnose ESS through a series of tests. These may include:

  • Physical examination – looking at and feeling any lump.
  • A scan – taking pictures of the inside of the body using scans such as an ultrasound, x-ray, CT, MRI or PET scans.
    • For ESS, the type of ultrasound used is often a transvaginal ultrasound. Doctors gently insert an ultrasound probe into the vagina to see a clear image of the uterus.
  • A hysteroscopy – doctors perform a hysteroscopy by inserting a thin tube through the vagina, cervix, and into the uterus. They can then look for any signs of ESS and can also take a biopsy if needed.
  • A biopsy – taking and testing a sample of the tumour. Using this biopsy, a doctor will look to see if the biopsy looks like ESS.

To read more about these scans and tests, click here.



The main treatment method for ESS is surgery. The type of surgery you have can depend on how far the cancer has spread.

  • If the cancer is very small, surgeons can remove the cancer from the uterus and “leave a margin”. This means a bit of healthy tissue is also taken to make sure that all the cancer is removed.

  • If the cancer is larger, a total hysterectomy may be done. This involves removing the whole uterus.

  • If the cancer is very large and has spread to areas near to the uterus, the following surgeries might be done:

    • A radical hysterectomy, which removes the uterus, nearby tissues, and upper part of the vagina.

    • A surgery called a total or radical hysterectomy with bilateral salpingo-oophorectomy. It removes the uterus, fallopian tubes, and ovaries.

      • If your ovaries are removed during a hysterectomy, you will go through the menopause, if you haven’t already. This is known as a surgical menopause.

After any type of hysterectomy, you’ll no longer be able to get pregnant. If you want to have children in the future, you can talk to your doctor about possible fertility treatments.


  • This treatment uses high-energy radiation to destroy cancer cells.
  • You may have radiotherapy either before or after surgery.
    • Before surgery, radiotherapy aims to shrink the tumour, making it easier to remove.
    • After surgery, radiotherapy aims to kill any cancer cells that surgery didn’t remove.


This treatment uses anti-cancer drugs to destroy cancer cells. Doctors may use it if you have a high risk of cancer returning. They might also use it if your cancer has spread (metastasis).

Hormone therapy

The growth of some ESS tumours is driven by hormones. Hormone therapy is a treatment that blocks or reduces specific hormones in the body. It can sometimes help to slow down the growth of these types of ESS tumours.

Targeted and experimental therapies

Researchers have been learning more about treatments known as “targeted therapies” and “immunotherapies”.

Targeted therapy is a treatment that stops cancer cells from growing and spreading. It targets specific characteristics within the cells.

Immunotherapy is a treatment that helps your immune system kill cancer cells.

Clinical trials have found that some targeted and immunotherapies work well for ESS. But, more research and trials are needed before these treatments are approved.

You might have a chance to join a study that looks into new ways to diagnose, treat, or use medications. Some studies also look at the care and well-being of patients. Your doctor or nurse can tell you about opportunities to join a clinical trial.

There are trials currently recruiting patients with ESS. For more information, please follow this link.

After treatment

After treatment, you will have regular follow-up appointments for several years. You should receive a follow-up schedule from your sarcoma clinical nurse specialist. The follow-ups will usually include:

  • A chance to discuss symptoms.
  • An examination to look for any signs of ESS returning. This may include scans such as CT, MRI or ultrasound scans.
  • A chest x-ray to rule out any secondary cancers occurring in the lungs.

Living with

After treating a previous tumour, ESS can come back in the same place. This is known as a “local recurrence.”

If the cancer reappears, you should have treatment as quickly as possible. Your treatment plan may include more surgery or radiotherapy, depending on what you need. You can check for recurrences by examining yourself and examining any unusual bleeding or discharge. Your doctor or sarcoma nurse can tell you what to look for.

If you are worried about your cancer returning, please contact your doctor or nurse. They might move your follow-up appointment date earlier to look into your concerns.


What if my cancer spreads to another part of my body?

A recurrence of ESS may be accompanied by cancer in other parts of the body. This is called “metastasis” or “secondary cancer”. Some people are diagnosed with sarcoma because their tumour has spread before their primary ESS tumour. In ESS patients, these secondary cancers can show up in the lungs. That’s why chest x-rays are done during follow-up appointments.

Secondary cancers may also appear in the bones, abdomen, pelvic region, and lymph nodes. If you have secondary cancer, your treatment may involve surgery, radiotherapy, or other therapies. Doctors will evaluate your treatment on a case-by-case basis.

If you have any questions or if you need to talk to someone, our Support Line team are here for you.


More information –

A scientific review on endometrial stromal sarcomas

Last reviewed: 24 November 2023

Next review due: 24 November 2026


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