What is Ewing sarcoma?
Ewing sarcoma is a type of malignant (cancerous) tumor that mainly affects children, teens, and young adults. These tumors are most often found in bones—particularly the pelvis and longer bones of the arms and legs—but also occasionally develop in soft tissues.
Ewing sarcomas are the second most common cancer starting in bones of patients age 18 or younger, but are still fairly rare. They represent just 1 percent of pediatric cancers, with about 200 children and teens in the U.S. receiving a diagnosis each year. While treatable, Ewing sarcomas are often aggressive, damaging bone and potentially metastasizing (spreading), usually to the lungs or other bones.
The Sarcoma Program at Penn Medicine’s Abramson Cancer Center is home to one of the nation’s most experienced Ewing sarcoma care teams. Our specialists work closely with the sarcoma program at the Children’s Hospital of Philadelphia to bring children the most effective treatment for Ewing sarcoma.
Types of Ewing sarcoma
Ewing sarcoma includes several types of related tumors. While there are some differences between them, their cells are similar and their treatments are the same. Together, these tumors are referred to as the Ewing family of tumors and include:
- Ewing sarcoma of bone: This bone sarcoma most commonly develops in the middle of bones but can occur at either end as well. While it’s mainly found in the pelvis and longer bones of the shins, thighs, and upper arms, it can also affect the hips, ribs, and shoulder blades. It’s the most common form of Ewing sarcoma.
- Extraosseous Ewing tumor (EOE): These Ewing tumors form as soft tissue sarcomas, often in the muscles. They’re typically found in the chest, abdomen (belly), arms, or legs. Doctors also call these tumors extraskeletal Ewing sarcomas.
- Primitive neuroectodermal tumor (PNET): These rare tumors form as either bone sarcomas or soft tissue sarcomas. In the chest, they’re called Askin tumors.
How Ewing sarcoma can affect the body
Ewing sarcomas may not cause symptoms until the tumor has grown large enough to be seen or felt. These tumors start in the bone but can break into the surrounding muscle and may cause a bump. These bumps typically appear in the pelvis, arms, or legs, but may also occur in the chest.
Ewing sarcoma symptoms you may experience include:
- Bone pain at the site of the tumor
- Lump or bump that may feel soft or warm, if the sarcoma has progressed out of the bone
- Broken bones from even moderate injuries
- Fever
- Unexpected weight loss
What causes Ewing sarcoma?
Researchers don’t fully understand why Ewing sarcoma forms. Understanding these tumors is difficult because they are rare and form in tissues that are still developing as children grow.
Unlike some other bone cancers, we don’t have evidence that Ewing sarcomas run in families or have ties to previous medical treatments. For now, there’s no known way to reduce the risk of developing Ewing sarcoma.
Testing for Ewing sarcoma
If our care team suspects Ewing sarcoma, we’ll talk with you about symptoms and perform a physical exam focused on any concerning lump, bump, or area of pain.
You may begin with imaging tests to examine the area of concern and identify any growths that need a closer look. If a tumor is suspected, we may recommend additional imaging to learn more about its size, location, and relationship to nearby tissues.
In addition to scans, we typically take a small sample of the tumor during an image-guided procedure called a biopsy. Analyzing the sample and using sophisticated molecular tests helps our team confirm a diagnosis and learn more about the cancer.
Together, the exam, imaging, and biopsy help us better understand the Ewing sarcoma. This process, called staging, provides important information about the tumor and helps us plan the most appropriate treatment.
Building the right treatment plan
The outlook for Ewing sarcoma depends on where the tumor forms, its size, and whether it has spread. Age is also an important consideration because treatment may affect growing bones. Because Ewing sarcoma is rare, it’s important to receive care from a team with extensive experience treating these tumors.
Your care team will develop a treatment plan based on the tumor's characteristics and your individual needs. Depending on the location and extent of the cancer, this may involve a combination of approaches designed to remove or destroy the tumor while preserving function whenever possible.
When surgery is recommended, our surgeons use advanced techniques to remove the tumor while preserving limbs whenever possible. We also work closely with plastic surgeons to help restore appearance, function, and future growth potential when reconstruction is needed.
Even after successful treatment, Ewing sarcoma can return. Regular follow-up visits allow us to monitor your recovery, watch for signs that the cancer has come back, and recommend additional treatment if needed.
Researchers are developing other treatment options for Ewing sarcoma, including targeted therapy and immunotherapy. Our program offers clinical trials for sarcoma.
Experience matters in Ewing sarcoma care
Ewing sarcoma requires a highly specialized approach. At Penn Medicine, surgeons, medical oncologists, radiation oncologists, radiologists, pathologists, and other sarcoma specialists work together to diagnose and treat these tumors. During weekly tumor board conferences, the team reviews complex cases and develops tailored treatment recommendations based on each person's needs.
As a member of the Sarcoma Alliance for Research through Collaboration (SARC), Penn Medicine helps advance research into rare cancers like Ewing sarcoma. Our program offers access to sarcoma clinical trials evaluating promising new therapies and treatment approaches that may not be widely available.
Rated “exceptional” by The National Cancer Institute
Penn Medicine’s Abramson Cancer Center is a world leader in cancer research, patient care, and education. Our status as a national leader in cancer care is reflected in our continuous designation as a Comprehensive Cancer Center by the National Cancer Institute (NCI) since 1973, one of 7 such centers in the United States. The ACC is also a member of the National Comprehensive Cancer Network, one of a select few cancer centers in the U.S., that are working to promote equitable access to high-quality, advanced cancer care.