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How to speak ES A guide to 

helpful terms

About ES

What you need to know about epithelioid sarcoma (ES)

Here you can find more about: 

What is epithelioid sarcoma (ES)?
ES symptoms
What causes ES?
Diagnosing ES
How ES may change

What is epithelioid sarcoma (ES)?

ES is a rare type of cancer7-9

ES belongs to a group of cancers called soft tissue sarcomas that develop in the soft tissues of the body, like muscles, fat, blood vessels, tendons, nerves, and lymph vessels.2,4,7-9,11

ES primarily affects people between the ages of 10 and 45, with an average age of 27,5,7-9,11 and often starts as a hard, usually painless lump in the soft tissue under the skin.7-9,11

An ES lump can appear anywhere in the body, but they're most often found in the fingers, hands, arms, feet, and legs.7-9,11

There are two types of ES:7

Lineart icon depicting the human body
  • Distal ES is the most common type, affecting the hands, arms, feet, legs, and other areas further away from the center of the body.7


  • Proximal ES is less common and affects areas closer to the body’s center, such as the chest, abdomen, pelvis, genitals, and back.7

ES is very rare, making up less than 1% of all soft tissue sarcomas and less than 0.01% of all cancers.8,9,11

ES is twice as common in men as in women.8,9

ES symptoms

What symptoms might someone with ES have?

People with ES may find a hard, slow-growing lump, also known as a tumor, in the soft tissues under the skin.8,9

Lineart icon showing a hand, with a lump present on one finger

These lumps are usually painless, but may hurt if they form in certain places, such as in your joints.8

A lump which appears shiny

Lumps may appear shiny and have a gray or tan color.8

A lump with an open top

The skin on these lumps may bleed regularly or develop sores called ulcers.8,9

What causes ES?

Understanding the causes of ES

The cause of ES is unknown.13 However, in most patients, it starts because of an error in a gene called SMARCB1 which codes for a protein called INI1. This error may cause cells to grow uncontrollably, forming a tumor.7-9

An error in SMARCB1 gene
Error in SMARCB1 gene
Arrow Arrow
A number of cells, one of which is dividing into two cells
Uncontrolled 
cellular growth
Arrow Arrow
Lineart icon showing a hand, with a lump present on one finger
ES tumor

ES tumors often form in parts of the body that have previously been injured, such as the hands, feet, arms, and legs. However, there's no proof that injuries can cause ES.8,9

Diagnosing ES

How is ES diagnosed?

The journey to an ES diagnosis is often lengthy and complex, typically involving consultations with multiple specialists.2,9,11,12

Early diagnosis is key, as treatment is much less effective after metastasis.11,12 However, diagnosing ES is challenging due to its rarity, slow growth, and resemblance to other cancerous, noncancerous, or inflammatory conditions, often causing delays in identification or misdiagnosis.7-9,11,14,15

A few different tests are used to diagnose ES: 

A stethoscope

Physical examination: Your doctor will need to look at and feel any lumps you have.1,2,9

An MRI machine

Scans: You may have magnetic resonance imaging (MRI), computed tomography (CT), or positron emission tomography-computed tomography (PET-CT) scans to see how big your lump is and whether you have any others.1,2,5,9

Lineart icon showing a microscope

Biopsy: This is when a doctor removes a small piece of your lump to look at under a microscope.1,2,5

  • Most of the time, a biopsy can be taken with a needle, though some need to be done surgically.1,2,5
  • The biopsy sample will be checked to see whether it looks like ES, as well as for signs of mistakes in the SMARCB1 gene or loss of the INI1 protein.7-9
A patient speaking with a doctor

If you have a lump that’s growing or changing, speak to your doctor today.

Always speak to your doctor about any symptoms you may have.

A couple standing together looking at a phone

“I had no idea that there were so many more things that could be gained from diagnostic testing”

– Natasha,* mother of a patient with ES

*Natasha has been compensated for her time in sharing her perspectives on ES

How ES may change

How might my ES change over time?

    Unfortunately, ES comes back after initial treatment in around 40%-50% of patients.16,17
    • ​​​​When ES comes back after treatment, this is called recurrence8,9,18
    • Recurrence usually happens within 1 to 2 years, but can happen at any time after treatment9
    • Local recurrence comes back in the same general area as the original tumor.9 If it occurs distantly, it's referred to as metastasis8
    • If your ES recurs, your doctor or healthcare team will work with you to explore and discuss available treatment options3
      ES can spread to other parts of the body, which happens in around 50% of patients.16,17
      • ​​​​​When a cancer, like ES, spreads to another part of the body, this is called metastasis, and cancer that has spread is called metastatic cancer19
      • The most common areas for distant metastasis are the lungs, bones, and brain8,9
      • Cancer that has spread may be harder to treat8
      • ES can spread via the lymphatic system – a part of your immune system that “cleans” the blood, helps your body absorb fats, and makes white blood cells to defend the body against harmful particles20
        • ES can spread to nearby lymph nodes, which are “centers” for the lymphatic system and can be found all around the body; from your lymph nodes, ES can spread to other parts of your body7,9
        • If your doctor thinks your ES has metastasized, they may take a biopsy of nearby lymph nodes8,9
      • ​​​​​Your doctor may recommend surgery to remove lymph nodes near the ES tumor to help stop ES spreading to other parts of your body8,9
      Learn about treatment of ES
      References
      1. National Cancer Institute. Soft Tissue Sarcoma Treatment (PDQ®)–Patient Version. Available at https://www.cancer.gov/types/soft-tissue-sarcoma/patient/adult-soft-tissue-treatment-pdq. Accessed February 2025.
      2. Shakya S, Banneyake EL, Cholekho S, et al. Soft tissue sarcoma: clinical recognition and approach to the loneliest cancer. Explor Musculoskeletal Dis. 2024;2:56-68.
      3. von Mehren M, Kane JM, Bui MM, et al. NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 1.2021. J Natl Compr Canc Netw. 2020;18:1604-1612.
      4. Bansal A, Goyal S, Goyal A, et al. WHO classification of soft tissue tumours 2020: an update and simplified approach for radiologists. Eur J Radiol. 2021;143:109937.
      5. National Cancer Institute. Soft Tissue Sarcoma Treatment (PDQ®)–Health Professional Version. Available at https://www.cancer.gov/types/soft-tissue-sarcoma/hp/adult-soft-tissue-treatment-pdq. Accessed February 2025.
      6. National Cancer Institute. Osteosarcoma Treatment (PDQ®)–Patient Version. Available at https://www.cancer.gov/types/bone/patient/osteosarcoma-treatment-pdq#_1. Accessed February 2025.
      7. Czarnecka AM. Epithelioid sarcoma. NOWOTWORY Journal of Oncology. 2023;73(3):154-161.
      8. Czarnecka AM, Sobczuk P, Kostrzanowski M, et al. Epithelioid sarcoma – from genetics to clinical practice. Cancers. 2020;12:2112.
      9. Needs T, Fillman EP. Epithelioid sarcoma. Updated July 2, 2024. Available at https://www.ncbi.nlm.nih.gov/books/NBK532911/. Accessed February 2025.
      10. Barrett L, Elliott E, Voorhaar M, et al. A mixed-methods study to better measure patient-reported pain and fatigue in soft tissue sarcoma. Oncol Ther. 2023;11(1):129-143.
      11. Recommendations from the Epithelioid Sarcoma Collaborative: a white paper. Available at https://www.jons-online.com/issues/2021/september-2021-vol-12-no-9/3914-recommendations-from-the-epithelioid-sarcoma-collaborative-a-white-paper. Accessed February 2025.
      12. Soomers V, Husson O, Young R, et al. The sarcoma diagnostic interval: a systematic review on length, contributing factors and patient outcomes. ESMO Open. 2020;5(1):e000592.
      13. Alves A, Constantinidou A, Thway K, et al. The evolving management of epithelioid sarcoma. Eur J Cancer Care (Engl). 2021;30(6):e13489.
      14. Martin S, Clark SE, Gerrand C, et al. Patients' experiences of a sarcoma diagnosis: a process mapping exercise of diagnostic pathways. Cancers (Basel). 2023;15(15):3946.
      15. Younger E, Husson O, Bennister L, et al. Age-related sarcoma patient experience: results from a national survey in England. BMC Cancer. 2018;18(1):991.
      16. de Visscher SA, van Ginkel RJ, Wobbes T, et al. Epithelioid sarcoma: still an only surgically curable disease. Cancer. 2006;107(3):606-612.
      17. Halling AC, Wollan PC, Pritchard DJ, et al. Epithelioid sarcoma: a clinicopathologic review of 55 cases. Mayo Clin Proc. 1996;71(7):636-642.
      18. National Cancer Institute. Recurrence. Available at https://www.cancer.gov/search/results?swKeyword=recurrence. Accessed February 2025.
      19. National Cancer Institute. Metastatic cancer: when cancer spreads. Available at https://www.cancer.gov/types/metastatic-cancer. Accessed February 2025.
      20. Null M, Arbor TC, Agarwal M. Anatomy, lymphatic system. Updated March 6, 2023. Available at https://www.ncbi.nlm.nih.gov/books/NBK513247/. Accessed February 2025.
      21. National Cancer Institute. Localized therapy. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/localized-therapy#. Accessed February 2025.
      22. National Cancer Institute. Systemic therapy. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/systemic-therapy. Accessed February 2025.

      How to speak ES A guide to 

      helpful terms

      Cross icon 

      How to speak epithelioid sarcoma (ES)

      A guide to some helpful terms

      Biopsy

      A procedure to remove a tiny piece of tissue from the body so it can be examined under a microscope.1

      Bone sarcoma

      A cancer of the bone that usually affects the large bones of the arm or leg. Also referred to as osteosarcoma or osteogenic sarcoma.2

      Cancer

      A type of disease that happens when cells in the body divide and grow out of control or do not die when they naturally should.3

      Computed tomography (CT)

      A scan that uses X-rays and computer technology to take detailed pictures of the inside of the body.4

      Distal ES

      The most common type of ES that typically affects the hands, arms, feet, legs, and other areas further away from the center of the body.5,6

      Epithelioid sarcoma (ES)

      A rare type of cancer that forms in the soft tissues of the body. It may start in the soft tissue under the skin of a finger, hand, arm, leg, or foot.5,6

      Gene

      A piece of the DNA that contains the instructions for making a specific protein in the body.7

      Immune system

      The body's defense system that protects against infections and diseases by identifying and attacking harmful invaders like bacteria, viruses, and abnormal cells.8

      Localized treatment

      Treatment that is directed to a specific organ or limited area of the body, such as an abnormal growth on the skin.9

      Lymph nodes

      Small structures that filter out harmful substances and help the body fight infections.10

      Lymph vessels

      Thin tubes that transport lymph fluid and white blood cells throughout the body to support immune function.11

      Lymphatic system

      A network of vessels, tissues, and organs that help remove waste and toxins, as well as fight infections in the body.11

      Magnetic resonance imaging (MRI)

      A scan that uses powerful magnets and radio waves to take detailed pictures of the inside of the body.12

      Malignant

      A term used to describe cancer. Malignant cells grow uncontrollably, can invade nearby tissues, and may spread to other parts of the body through the bloodstream or lymphatic system.13

      Metastasis

      The spread of cancer from where it started to another part of the body.14

      Metastatic cancer

      Cancer that has spread from where it first started to another part of the body.15

      Positron emission tomography-computed tomography (PET-CT)

      A procedure that combines the pictures from a positron emission tomography (PET) scan and a computed tomography (CT) scan. The combined scans give more detailed pictures of areas inside the body than either scan gives by itself.16

      Proximal ES

      A type of ES that forms in areas close to the center of the body, such as the chest, abdomen, pelvis, and back. It is less common than distal ES.5,6

      Radiotherapy

      High-energy rays used to destroy cancer cells and shrink tumors.17

      Recurrence

      The return of cancer after successful treatment and a period when no cancer could be detected.18

      Sarcoma

      A type of cancer that starts in the bones or soft tissues of the body, like muscles, fat, cartilage, blood vessels, or other tissues that support or connect parts of the body.19

      SMARCB1

      A gene that provides instructions for a protein called INI1, which is involved in many processes, including DNA repair, DNA replication, and cell growth, division, and maturation.20 Most cases of ES involve an error or mutation in this gene.5,6

      Soft tissue sarcoma

      A group of different cancers that form in the soft tissues of the body, like muscles, fat, blood vessels, tendons, nerves, and lymph vessels.21

      Systemic treatment

      A treatment that circulates through the bloodstream, reaching cells throughout the body.22

      Tumor

      An abnormal clump of tissue that forms when cells divide and grow out of control or do not die when they naturally should.23

      Ulcer

      An open sore on the skin that fails to heal normally.24

      References
      1. National Cancer Institute. Biopsy. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/biopsy. Accessed February 2025.
      2. National Cancer Institute. Osteosarcoma. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/osteosarcoma. Accessed February 2025.
      3. National Cancer Institute. What is cancer? Available at https://www.cancer.gov/about-cancer/understanding/what-is-cancer. Accessed February 2025.
      4. National Cancer Institute. Computed tomography (CT) scans and cancer. Available at https://www.cancer.gov/about-cancer/diagnosis-staging/ct-scans-fact-sheet#what-is-computed-tomography. Accessed February 2025.
      5. Needs T, Fillman EP. Epithelioid sarcoma. July 2, 2024. Available at https://www.ncbi.nlm.nih.gov/books/NBK532911/. Accessed February 2025.
      6. Czarnecka AM, Sobczuk P, Kostrzanowski M, et al. Epithelioid sarcoma – from genetics to clinical practice. Cancers. 2020;12:2112.
      7. National Cancer Institute. Gene. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/gene. Accessed February 2025.
      8. National Cancer Institute. Immune system. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/immune-system. Accessed February 2025.
      9. National Cancer Institute. Localized therapy. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/localized-therapy. Accessed February 2025.
      10. National Cancer Institute. Lymph node. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/lymph-node. Accessed February 2025.
      11. National Cancer Institute. Lymphatic system. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/lymphatic-system. Accessed February 2025.
      12. National Cancer Institute. Magnetic resonance imaging (MRI). Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/magnetic-resonance-imaging. Accessed February 2025.
      13. National Cancer Institute. Malignant. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/malignant. Accessed February 2025.
      14. National Cancer Institute. Metastasis. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/metastasis. Accessed February 2025.
      15. National Cancer Institute. Metastatic cancer. Available at https://www.cancer.gov/types/metastatic-cancer. Accessed February 2025.
      16. National Cancer Institute. Positron emission tomography-computed tomography. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/positron-emission-tomography-computed-tomography-scan. Accessed February 2025.
      17. National Cancer Institute. Radiotherapy. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/radiotherapy. Accessed February 2025.
      18. National Cancer Institute. Recurrence. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/recurrence. Accessed February 2025.
      19. National Cancer Institute. Sarcoma. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/sarcoma. Accessed February 2025.
      20. MedlinePlus. SMARCB1 gene. Available at https://medlineplus.gov/genetics/gene/smarcb1/. Accessed February 2025.
      21. National Cancer Institute. Soft tissue sarcoma. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/sarcoma. Accessed February 2025.
      22. National Cancer Institute. Systemic therapy Available https://www.cancer.gov/publications/dictionaries/cancer-terms/def/systemic-therapy. Accessed February 2025.
      23. National Cancer Institute. Tumor. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/tumor. Accessed February 2025.
      24. National Cancer Institute. Ulcer. Available at https://www.cancer.gov/publications/dictionaries/cancer-terms/def/ulcer. Accessed February 2025.